00:00:08.080 Hello, so we're up to chapter 4 today. Before I begin, someone asked if I'd be doing video
00:00:14.960 similar to these but for people who haven't read the book and the answer I suppose is no
00:00:20.560 because that's the purpose of the book. If you haven't bought the book, if you haven't read the book
00:00:26.000 then I think that people should buy the book and maybe this can help you to understand some of
00:00:31.040 the parts. I often find it far better to have someone to discuss ideas with. I know there's
00:00:36.240 people out there that maybe aren't surrounded by others who are interested in philosophical
00:00:40.480 discussions and so maybe this can serve as a sort of support for that. So this is to help people
00:00:48.080 to understand the book. It's an extremely dense book, it's probably one of the most fascinating
00:00:53.680 broad-ranging deep books that have ever been written and so it is helpful to have someone else
00:01:01.120 I think to bounce ideas off and so if you hear someone else reading it and commenting on it,
00:01:06.080 that can help but as for people who haven't read the book at all and just wanted to spread the
00:01:12.560 ideas out there. Certainly that's great if people do that but I'm not going to provide a summary
00:01:19.360 I guess of the book if you want. People can buy the book to get the summary at the end of every
00:01:23.920 chapter is indeed a summary of that chapter. So that's all you wanted to do. That would be a great
00:01:29.680 way of at least getting an overview of the Deutcheon worldview for a wonderful better word.
00:01:34.960 So up to chapter four today, chapter four is called Creation. I find that it's essentially in two
00:01:41.120 parts. The first part is very much about biological knowledge and how it comes into being and
00:01:48.240 it's impact upon what is neodilinism or just evolution by natural selection as another way of
00:01:56.000 putting that. And the second part is really about fine tuning which is something I'm very interested
00:02:01.680 in. I'm fascinated by this concept of the fine tuning of the physical constants of nature.
00:02:07.200 There's been a number of books written specifically on that topic over the years and David has a
00:02:11.280 section here in chapter four and he makes a good contribution to the corpus of knowledge that's
00:02:16.160 been written there. So an interesting philosophical ideas. So in chapter four we do find that there are
00:02:22.320 many misconceptions about how stuff in general is created that people have become subject to
00:02:32.240 over the years of trying to understand the appearance of design in nature. These misconceptions
00:02:39.440 pervade not only biological evolution but other kinds of creation like knowledge creation for
00:02:46.960 example which has a bearing on the psychology of learning how it is our minds learn. So in chapter
00:02:53.440 four David does go through the usual Dawkins and Harris and Hitchens, the atheist objections
00:03:00.720 to creationism but he does something a little bit deeper. He goes more fundamental than just
00:03:05.840 the biological. So in all cases he's trying to understand how the knowledge has become
00:03:12.880 instanciated where it is. In all cases he's trying to understand how the knowledge has been
00:03:16.400 created there. From my perspective it's only possible for knowledge to be created in one broad way
00:03:23.120 and I'm going to be a little bit lazy with the synonyms here but essentially the idea is that
00:03:27.760 you have a conjecture which is a mutation of some existing idea or some existing trial in the case
00:03:34.720 of biological organisms, possibly an adaptation or a change, a mutation of a gene in particular.
00:03:42.000 So this conjecture or this mutation is iterated with criticism or selection.
00:03:47.120 So this has a bearing on also bucket theories of mind which are still operative everywhere
00:03:53.200 and it shows how alternative epistemology is a false. The spontaneous generation of anything
00:04:01.440 that is sufficiently complicated is false and that's usually the error that's at
00:04:06.080 heart of any of these attempts to understand how it is that knowledge has come to be instanciated
00:04:12.080 where it is. So in the case of biological evolution and biological knowledge the issue there
00:04:19.920 is that we cannot have spontaneous generation of life as we will see because that would
00:04:25.200 presume that the knowledge somehow has come from nowhere. Creationists will say it's come from
00:04:31.600 God but then we merely have to ask the question how did God get the knowledge and if he always
00:04:35.760 had the knowledge then that doesn't solve any problems. We may as well say that nature already
00:04:41.200 had the knowledge there. Similarly bucket theories of mind are spontaneous generation theories
00:04:48.880 of how we learn. So someone who sits in a classroom and passively is supposed to be the recipient
00:04:55.040 of the knowledge passed on by the teacher or through reading a book is a spontaneous generation concept
00:05:02.160 that merely by virtue of the empty vessel remaining in a room and someone pouring knowledge into
00:05:09.120 the empty vessel that a person can learn. They won't because they need to conjecture the knowledge
00:05:15.200 themselves first and just as a related point this will only happen if they're interested in what
00:05:20.400 they're hearing or if they have some other kind of motivation but really they need interest.
00:05:26.400 Any other kind of motivation that you try and give them is probably going to be immoral,
00:05:29.920 for example if you say we punished if you don't gain this knowledge and this is why I
00:05:35.200 continue to argue that Iq was really an interest quotient. It just tells people how interested
00:05:40.960 an individual happens to be in doing the kind of tasks associated with intelligence tests,
00:05:47.200 so-called intelligence tests. Really what we have is a class of tasks, questions, kinds of knowledge
00:05:54.480 that people value and that yes sure might help you to be successful out there in the world
00:06:00.880 but some people aren't interested in that kind of thing. It doesn't mean that their brains are
00:06:04.400 any less capable of doing certain tasks. It means they're not interested in doing certain tasks
00:06:10.240 but this is taking us far afield or it's taking us a little afield from the central points
00:06:16.560 in chapter 4. So let me get into the reading and to also at this point I think people for the
00:06:21.760 email sort of been coming in I've been enjoying responding to those. They're great. So chapter 4
00:06:26.960 creation. I'll start from the beginning and read until I think it's time to comment.
00:06:32.560 You're right. The knowledge in human brains and the knowledge in biological adaptations are
00:06:36.880 both created by evolution in the broad sense. The variation of existing information
00:06:41.520 alternating with selection. In the case of human knowledge the variation is by conjecture and the
00:06:46.480 selection is by criticism and experiment. In the biosphere the variation consists of mutations,
00:06:52.240 random changes, in genes and natural selection favors the variance that most improve the ability
00:06:57.600 of their organisms to reproduce. Thus causing those variant genes to spread through the population
00:07:02.640 and natural selection favors the variance that most improve the ability of their organisms to
00:07:08.080 reproduce. Thus causing those variant genes to spread through the population. That
00:07:13.120 a gene is adapted to a given function means that few if any small changes would improve its
00:07:18.400 ability to perform that function. Some changes might make no practical difference to that ability
00:07:24.320 but most of those that did would make it worse. In other words good adaptations like good
00:07:29.840 explanations are distinguished by being hard to vary while still fulfilling their functions.
00:07:35.520 This is me speaking now. The concept of hard to vary discovered by David Deutsch,
00:07:40.880 the improvement beyond Popper, applies equally here to biological evolution as it does to a
00:07:48.800 epistemology. Back to the book. Human brains and DNA molecules each have many functions but among
00:07:55.680 other things they are general purpose information storage media. They are in principle capable of
00:08:00.960 storing any kind of information. Moreover the two types of information they respectively
00:08:06.720 evolve to store have a property of cosmic significance in common. Once they are physically embodied
00:08:12.800 in a suitable environment they tend to cause themselves to remain so. Such information,
00:08:18.640 which I call knowledge, is very unlikely to come into existence other than through the
00:08:23.760 error correcting process of evolution or thought. My commentary here now. That is so crucial
00:08:32.880 to understand there's a lot being packed into there as always. What we learn there is a new way
00:08:39.600 of viewing knowledge, knowledge being this kind of entity that once it has appeared in a particular
00:08:47.280 environment it will tend to cause itself to remain in that environment. It will copy itself.
00:08:53.600 We will replicate itself. It has this kind of robust capacity to avoid the usual vagaries of physical
00:09:01.120 forces. A rock, once it comes out of a volcano or whatever process that produces the rock,
00:09:07.520 isn't able to cause itself to remain in existence. It's subject to erosion or disappear eventually.
00:09:14.720 Typical species of organisms will tend to go extinct over time as the environment changes.
00:09:20.640 Very little has the property in physical reality of tending to cause itself to remain in existence.
00:09:30.880 One struggles to think of something else that tends to cause itself to remain physically embodied
00:09:38.160 in the environment. So we have this concept of tending to cause itself to remain in the environment
00:09:45.600 over time. Once embodied there in a suitable environment they tend to encore themselves to remain
00:09:51.920 so. And the other thing is that knowledge cannot come into existence other than through this process
00:09:59.680 of evolution or thought. So the two kinds of knowledge there. This biological type knowledge that
00:10:06.880 arrives on the scene due to evolution by natural selection. The process of variation and selection
00:10:14.080 or through thought the products of minds that people have. And that process is conjecture and
00:10:23.280 criticism or conjecture and refutation as pop would say. My commentary over let's continue reading.
00:10:28.160 There are also important differences between those two kinds of knowledge. One is that biological
00:10:33.040 knowledge is non-explanatory and therefore has limited reach. Explanatory human knowledge can have
00:10:38.880 broad or even unlimited reach. Another difference is that mutations are random while conjectures
00:10:44.560 can be constructed intentionally for a purpose. Nevertheless the two kinds of knowledge share
00:10:49.760 enough of their underlying logic for the theory of evolution to be highly relevant to human knowledge.
00:10:54.400 In particular some historic misconceptions about biological evolution have counterparts in
00:10:59.040 misconceptions about human knowledge. So in this chapter I shall describe some of those misconceptions
00:11:04.800 in addition to the actual explanation of biological adaptations namely modern Darwinian evolutionary
00:11:10.720 theory sometimes known as neo Darwinism. Now there's a subtitle and it says creationism.
00:11:17.120 Creationism is the idea that some supernatural being or beings designed and created all
00:11:22.400 biological adaptations. In other words the gods did it. As explained in chapter one theories of
00:11:28.960 that form are bad explanations. Unless supplemented by hard to very specifics they do not even
00:11:34.880 address the problem. Just as the laws of physics did it will never win you a Nobel Prize and the
00:11:40.160 chondra did it does not solve the mystery of the conjuring trick. Before a conjuring trick is
00:11:44.960 ever performed its explanation must be known to the person who invented it. The origin of that
00:11:49.280 knowledge is the origin of the trick. Similarly the problem of explaining the biosphere is that of
00:11:54.880 explaining how the knowledge embodied in its adaptations because possibly have been created.
00:11:59.200 In particular a putative designer of any organism must also have created the knowledge of how
00:12:04.160 that organism works. Creationism thus faces an inherent dilemma is the designer a purely
00:12:10.480 supernatural being one who is just there complete with all that knowledge or not. A being who is
00:12:15.920 just there would serve no explanatory purpose in regard to the biosphere. Since then one could
00:12:21.760 more economically say that the biosphere itself just happened complete with that same knowledge
00:12:27.440 embodied in organisms. On the other hand to whatever extent a creationist theory provides
00:12:32.240 explanations about how supernatural beings design and create the biosphere they are no longer
00:12:36.560 supernatural beings but merely unseen ones. They might for instance be an extraterrestrial
00:12:42.160 civilization but then the theory is not really creationism unless it proposes that the extraterrestrial
00:12:47.040 designers themselves had supernatural designers. Now there's a section about the idea that
00:12:54.240 surely if there was a supernatural designer they would have made things as good as possible.
00:13:00.320 Especially if it's a benevolent designer and an omniscient designer and David uses the famous
00:13:06.720 example of. In mammalian eyes for example in human eyes what you've got is an eyes where the light
00:13:14.240 sensitive part has its blood supply and the wiring the nerves in front of the light sensitive cells
00:13:23.120 so they're blocking some of the light. It didn't have to be this way in other animals it's not
00:13:27.760 and because the wiring the blood supply is in the front of the retina you then have to have a
00:13:33.200 system where all those wires and those and all those blood vessels have to get back to the brain.
00:13:38.880 So what they have to do is to dive in through the retina through what is the optical blind spot
00:13:43.520 back to the brain to buy the optic nerve back to the visual cortex. This is a terrible design.
00:13:49.040 Okay no engineer would come up with this no intelligent designer would come up with this.
00:13:53.280 I believe the octopus has an eye where all of the wiring is at the back and so there's no
00:13:58.880 degradation of the light coming in to their retinas so evolution was able to get it right in one
00:14:04.320 sense but not right in the other self it was an intelligent designer I don't know why he preferred
00:14:08.800 octopuses to mammals David actually says squids yes. There's also sections here about vestigial
00:14:16.800 features things like the appendix male may not have a function in human beings it seems to be a
00:14:24.640 degraded sequence as far as I remember David talks about the fact that we need vitamin C and yet
00:14:30.320 many other animals have genes for vitamin C that work but our gene for vitamin C doesn't work so we
00:14:36.800 have to go out and get our vitamin C from plant material so that seems to be a bad design
00:14:41.280 and it seems to be not a very benevolent thing for an all-powerful god to do to give us features
00:14:46.160 that generally cause us harm yet again the appendix or the tonsils are a pretty good example these
00:14:52.000 are things that often have to be operated on in human beings and removed without too much harm
00:14:57.680 so why they're still there will their vestigial they're left over from our evolutionary ancestors
00:15:02.960 that's the end of my commentary let some persevere with the book the central floor of creationism
00:15:09.040 that it's a count of how the knowledge and adaptations could possibly be created is either missing
00:15:14.080 supernatural or illogical is also the central floor of pre-enlightenment authoritative conceptions of
00:15:20.240 human knowledge in some versions it is literally the same theory certain types of knowledge
00:15:26.400 such as cosmology or moral knowledge and other rules of behavior being spoken to
00:15:31.200 all the humans by supernatural beings in others perochial features of society such as the existence
00:15:36.880 of monarchs and government or indeed the existence of god in the universe are protected by taboos
00:15:41.840 or taken so uncorrectly for granted that they are not even recognises ideas and I shall discuss
00:15:47.360 the evolution of such ideas and institutions in chapter 15 so I'm skipping quite a bit now
00:15:53.440 there's a long section on spontaneous generation which was the attempt early on by people to try
00:16:01.120 and explain how it is that biological organisms arose out of non-living material should say
00:16:09.680 we don't have a full explanation yet or even any explanation as to how inorganic material
00:16:17.680 becomes self replicating there must be a natural process that allows it but it's an open question
00:16:24.400 it can't in any case be spontaneous generation which is the idea that you can
00:16:28.720 leave alone a bunch of non-living stuff and eventually it will simply become a complicated organism
00:16:35.840 for what it's worth there trying to replicate the early conditions of the earth in
00:16:41.120 milliurae type experiments the milliurae experiment was this attempt to take a whole bunch of
00:16:48.080 inorganic material carbon dioxide methane oxygen nitrogen etc put in a flask with some water heated
00:16:55.520 up shoot electricity through it leave it for a little while and see what happens at the end
00:17:01.280 and I think initially in the first few iterations of the experiment anyway people were extremely
00:17:06.720 excited about the fact that they ended up producing amino acids of course amino acids aren't
00:17:12.720 life amino acids aren't life anymore than a pile of bricks is the Sydney Opera House if someone
00:17:19.600 said to you I'm doing some important work I'm building the Sydney Opera House and you say to them
00:17:24.640 show me your progress and they say sure no worries and they show you a brick this is hardly
00:17:29.440 evidence that they're well on their way to building the Sydney Opera House in a similar way
00:17:34.080 milliurae type experiments at least the early ones I haven't kept up with it but the early ones
00:17:38.640 were able to produce some very simple organic molecules things like amino acids maybe they produce
00:17:46.240 simple proteins I don't know they certainly didn't produce nucleic acids and they didn't
00:17:50.400 haven't yet produced anything that is self replicating so it's an interesting open question as to how
00:17:57.120 easy it is for inorganic material given our laws of physics to organize itself into self replicating
00:18:06.000 molecules how that happens and how easy it is we don't know the milliurae experiment seems to
00:18:11.360 suggest it might be difficult there are other kinds of ways of approaching the problem for example
00:18:17.680 looking at the geology of the early earth if you look at the geology of the early earth what you
00:18:21.440 find is that life arose here on planet earth as soon as the conditions were even marginally
00:18:27.840 okay for life to arise you know it was very soon after the earth solidified on its surface
00:18:36.000 so it was very very hot completely in hostile you know some thousands of degrees
00:18:39.200 selfies on the earth very early on but as soon as it cooled down the life appeared and you can
00:18:44.720 find this in geology the question then from geology is well it seems like it rose as quickly as
00:18:50.800 it possibly could here on earth which would suggest that it's rather easy for life to arise
00:18:57.600 we don't know it's it's it's a simple example maybe it's very very hard but the fact that it
00:19:01.920 rose quickly on earth is interesting in light of the fact that the smartest biologist working for
00:19:08.560 a long time now I haven't been able to replicate the process in the lab okay I'm going to read
00:19:13.840 the section now which is on page 83 and it's titled the argument from design the argument from
00:19:20.640 design has been used for millennia as one of the classic proofs of the existence of God as follows
00:19:27.600 some aspects of the world appear to have been designed but they were not designed by humans
00:19:32.480 since design requires a designer they must therefore be of God as I said that is a bad explanation
00:19:39.120 because it does not address how the knowledge of how to create such designs could possibly have
00:19:43.520 been created who designed the designer and so on but the argument from design can be used in
00:19:49.280 valid ways too and indeed it's earliest known use by the ancient Athenian philosopher Socrates
00:19:55.040 was valid the issue was given that the gods have created the world do they care what happens
00:20:01.520 in it Socrates pupil Aristodemus had argued that they do not another pupil the historian Xenophon
00:20:08.800 records Socrates reply Socrates because our eyes are delicate they have been
00:20:16.400 shuttered with eyelids that open when we have occasion to use them and our foreheads have been
00:20:22.160 fringe with eyebrows to prevent damage from the sweat of the head and the mouth set close to
00:20:28.240 the eyes and nostrils as a portal of ingress for all our supplies whereas since matter passing
00:20:34.400 out of the body is unpleasant the outlet to directed hindwoods as far away from the senses as
00:20:39.280 possible I ask you when you see all these things constructed with such show of foresight can you
00:20:46.560 doubt whether they are products of chance or design Aristodemus certainly not viewed in this light
00:20:54.000 they seem very much like the contrivances of some wise craftsmen full of love for all living things
00:20:59.600 Socrates and what of the implanting of the instinct to procreate and in the mother the instinct
00:21:06.160 to rear her young and in the young the intense desire to live and the fear of death Aristodemus
00:21:12.640 these provisions too seem like the contrivances of someone who has determined that their shall
00:21:17.280 be living creatures that might commentary on that before I go back to the book this is where I
00:21:23.120 suppose our Richard Dawkins or any other evolutionary biologist would jump in rightly and say that
00:21:28.640 this is a forced dichotomy where Socrates says can you doubt whether our products have chance or
00:21:34.560 design and so he's meaning there the exclusive or it has to be one or the other and of course we
00:21:42.240 know that it is neither of those things now okay so this is a trap that many people fall into they
00:21:49.440 can only see two options and so therefore they conclude there are only two options but your lack
00:21:55.280 of imagination is not a refutation of the possibility that you're wrong so let's go back to the
00:22:01.200 let's go back to the text Socrates was right to point out that the appearance of design and
00:22:05.200 living things is something that needs to be explained it cannot be the product chance and that is
00:22:10.320 specifically because it signals the presence of knowledge how was that knowledge created however
00:22:16.320 Socrates never stated what constitutes an appearance of design and why do crystals and rainbows have
00:22:21.200 it there's the sun or summer how are they different from biological adaptation such as eyebrows
00:22:27.440 the issue of what exactly needs to be explained in an appearance of design was first addressed
00:22:33.520 by the clergyman William Pailey the finest exponent of the argument from design in 1802 before
00:22:39.280 Darwin was born he published the following thought experiment in his book Natural Theology he
00:22:44.480 imagined walking across a heath and finding a stone or alternatively a watch in either case he
00:22:50.480 imagined wondering how the object came to exist and he explained why the watch would require a
00:22:56.000 holy different kind of explanation from that of the stone for all he knew he said the stone
00:23:01.600 might have laying there forever today we know more about the history of the earth so we should
00:23:06.960 refer instead to supernova transmutation and the earth's cooling crust but that would make no
00:23:12.160 difference to Pailey's argument his point was that sort of account can explain how the stone came
00:23:18.560 to exist or the raw materials for the watch but it could never explain the watch itself
00:23:25.680 a watch could not have been lying there forever nor could it have formed during the solidification of
00:23:30.240 earth unlike the stone or rainbow or a crystal it could not have assembled itself by spontaneous
00:23:35.920 generation of from its raw materials nor could it be a raw material but why not exactly asked
00:23:41.680 Pailey why should not this answer serve for the watch as well for the stone why is it not as
00:23:47.200 admissible in the second case as in the first and he knew why because the watch not only serves
00:23:54.320 a purpose it is adapted to that purpose Pailey wrote quote for this reason and for no other
00:24:00.720 views that when we come to inspect the watch we perceive what we could not discover in the stone
00:24:06.800 that it's several parts of framed and put together for a purpose for example they are so formed
00:24:12.880 and adjusted as to produce motion and that motion so regulated as to point out the hour of the day
00:24:19.120 end quote back to the book one cannot explain why the watch is as it is without referring to its
00:24:27.520 purpose of keeping accurate time like the telescopes I discussed in chapter two it is a rare
00:24:32.480 configuration of matter skipping a little so people must have designed that watch
00:24:39.360 Pailey was of course implying that all of this is even more true of a living organism
00:24:45.200 say a mouse it's several parts are all constructed and appear to be designed for a purpose
00:24:50.880 for instance the lenses in its eyes have a purpose similar to that of a telescope
00:24:55.200 the focusing light to form an image on its retina which in turn has the purpose of recognizing
00:25:00.080 food danger and so on actually Pailey did not know the overall purpose of the mouse
00:25:05.920 that we do now see near Darwinism which we're about to come to but even a single eye would
00:25:11.280 suffice to make Pailey's triumphant point namely that the evidence of a parent design for a
00:25:16.960 purpose is not only that the parts all serve a purpose but they were but if they were slightly
00:25:24.480 altered they would serve it less well or not at all a good design is hard to vary
00:25:30.960 quote if the different parts had been differently shaped from what they are of a different size
00:25:38.880 from what they are or placed after any other manner or in any other order then that which they
00:25:44.400 are placed either no motion at all would have been carried on in the machine or none which would
00:25:49.680 have answered the use that is now served by it end quote so David says here this is so my commentary
00:25:56.960 David says here that the knowledge there has come to be embedded in the watch it's also embedded
00:26:03.600 in the mouse as well and so now I'll go back to the book and you're right so how did all that
00:26:09.040 knowledge come to be embodied in those things as I said Pailey can conceive of only one explanation
00:26:15.200 that was his first mistake quote the inference we think is inevitable that the watch must have had
00:26:21.360 a makeup they cannot be designed without a designer contrivance without a contriver order without choice
00:26:27.440 arrangement without anything capable of arranging subservancy and relation to a purpose without
00:26:32.480 which without that which could intend a purpose mean suitable to an end without the end having
00:26:38.640 ever been contemplated or the means accommodated to it arrangement disposition of parts subservancy
00:26:44.640 of means to an end relation of instruments to a use imply the presence of intelligence and
00:26:50.880 mind we now end quote back to the book we now know that they can be designed without a designer
00:26:58.880 knowledge without a person who created it some types of knowledge can be created by evolution
00:27:04.400 I shall come to that shortly but it is no criticism of Pailey that he was unaware of a discovery
00:27:09.840 that had yet to be made one of the greatest discoveries in the history of science so David then
00:27:15.040 goes on to speak about how Pailey understood the problem even if he didn't realize the solution
00:27:21.120 and the solution contained the problem because his solution was of course there's an ultimate
00:27:25.200 designer so if you find a watch then you're right to conclude that there must have been a designer
00:27:30.880 and Pailey arguable therefore if you find a mouse then the mouse must have had a designer because
00:27:35.200 the mouse is even more complicated than what the watch is so therefore got exists but it doesn't
00:27:40.080 actually solve the problem because this ultimate designer itself must have had a maker this is an
00:27:47.760 objection that's been raised many many times by many many different people and David admits that
00:27:52.640 this isn't a proof of the non-existence of God it just shows that that particular argument for
00:27:58.080 God is a bad one and then we move on to Lamar Kism again I'm not going to read the entire section
00:28:04.400 here interesting though it is so I'm just going to skip to the main points and so now we're
00:28:10.720 getting it to Lamar Kism I'm going to skip over a lot of it David's writing about the first
00:28:15.120 attempts to try and understand how it is that biological organisms seem well suited to the
00:28:22.400 environments in which they're found David writes during the early years of the 19th century the
00:28:28.320 naturalist John Baptiste Lamarck proposed an answer that is now known as Lamar Kism it's key idea
00:28:34.160 is that improvements acquired by an organism during its lifetime can be inherited by its offspring
00:28:39.120 Lamarck was thinking mainly of improvements in the organisms organs limbs and so on such as for
00:28:44.400 instance the enlargement and strengthening of muscles that an individual uses heavily
00:28:48.800 and the weakening of those that it seldom does skipping a little the Lamarckian explanation of
00:28:53.840 giraffes is that when eating leaves from trees whose lower lying leaves were already eaten
00:29:00.080 stretch their necks to get at the higher ones this supposedly lengthened their neck slightly
00:29:05.200 and then they're offspring inherited that trait of having slightly longer necks
00:29:09.360 thus over many generations long neck giraffes evolved from ancestors with unremarkable necks
00:29:14.560 in addition Lamarck proposed an improvements were driven by a tendency built into the laws of
00:29:19.200 nature towards ever greater complexity the latter is a fudge for not just any complexity could
00:29:25.600 account for the evolution of adaptations it has to be knowledge and so that part of the theory is
00:29:30.480 just invoking spontaneous generation unexplained knowledge Lamarck might not have minded that
00:29:35.440 because like many think it's a these day he took the existence of spontaneous generation for granted
00:29:41.120 so I'll pause there there are all sorts of problems with the markers and this makes me think of
00:29:45.440 another misconception people have about evolution that is directed towards ever greater complexity
00:29:50.400 what kind of complexity we're never really told but people have this notion that perhaps it's
00:29:55.360 moving towards greater complexity in forms of more intelligence or bigger brains something like that
00:30:03.440 and so people often think that evolution is directed towards creating more intelligent species
00:30:10.320 and so in our evolutionary history when we look back there was some other kind of hominid
00:30:16.240 that had a slightly smaller brain and before that as a shorter smaller brain hominid and so on
00:30:22.240 stretching back to some kind of ape thing and then perhaps to some kind of monkey thing and then
00:30:27.280 to some other kind of simple mammal and then some other kind of amphibian thing and some other
00:30:32.320 kind of fish thing the brains get smaller and smaller smaller so it appears as though from our
00:30:36.320 perspective looking back that evolution has led to us so why shouldn't we find aliens out there
00:30:44.880 that have big brains surely if it's happened here on earth it'll happen somewhere else out
00:30:50.400 there as well now there are many many problems with this argument but I just want to consider the
00:30:54.400 giraffe for a moment if you've got an anthropomorphic giraffe and the anthropomorphic giraffe
00:30:59.840 is able to contemplate its own existence in evolutionary history it might look back at its ancestors
00:31:05.520 and notice that all of those have had slightly shorter necks that became longer and longer and longer
00:31:11.920 at culminating in a really long neck so then the question becomes for a giraffe that's interested
00:31:18.160 in astrobiology should we expect out there in the universe to find other things with really long necks
00:31:24.080 after all if it happened here on earth it'll happen elsewhere out there but when you look around
00:31:29.200 here on the earth at all the species that are alive today you don't find many with long necks
00:31:37.600 maybe you can consider certain kinds of dinosaurs so maybe it's a possibility but it's not like
00:31:43.520 it's a convergent feature of evolution typically not many species have long necks with humans it's
00:31:51.360 even worse it's even worse it doesn't seem like any other species perhaps had the intelligence
00:31:58.960 that we did perhaps there were there might have been Neanderthals or chromagnan man or something like
00:32:06.000 that but I would guess that all of these kind of hominids actually had an intelligent
00:32:13.360 common ancestor and so that intelligent common ancestor that's the thing that I'm interested in
00:32:18.880 finding out whether or not there might have been independent big brain general purpose explainers
00:32:24.640 out there this argument by the way is due to Charles Lineweaver Charlie Lineweaver who's an
00:32:30.160 astrophysicist astrobiologist of the Australian National University and he calls it the planet of
00:32:34.640 the apes hypothesis and he actually uses the example of an elephant and the length of trunks and
00:32:41.040 he does a good statistical analysis of long trunked things over time and if you look at the length
00:32:47.920 of trunks leading to elephants you might very well conclude that this is what evolution is about
00:32:53.520 it's about making ever longer trunks but that is simply confirmation bias from the perspective of
00:32:58.480 an elephant and so perhaps we have a similar kind of confirmation bias when it comes to human beings
00:33:04.240 with the only species we know of that is intelligent that's alive today so if we go looking out
00:33:09.680 there into outer space for intelligent aliens we might be sorely disappointed they might not be
00:33:15.840 any out there even if the entire cosmos is filled with with bacteria covered planets none of
00:33:22.160 them might evolve intelligence there's more to say on that I'll leave it for another time
00:33:27.200 back to the text I'm skipping a lot more now David writes the fundamental error being made my
00:33:32.560 landmark has the same logic as inductivism both assume that new knowledge adaptations and scientific
00:33:38.160 theories respectively is somehow already present in experience or can be derived mechanically
00:33:43.840 from experience but the truth is always that knowledge must first be conjectured and then tested
00:33:49.120 that is what Darwin's theory says first random mutations happen they did not take account of what
00:33:55.680 problem is being solved then natural selection the scars the variant genes that are less good
00:34:00.560 at causing themselves to be present again in future generations okay so now we get to the
00:34:05.600 section subtitled neo Darwinism and I'm going to read a fairly lengthy bit here because I think
00:34:11.040 it's very instructive to get the David Deutsch perspective on neo Darwinism okay so David
00:34:18.720 writes the central idea of neo Darwinism is that evolution favors the genes that spread best through
00:34:25.840 the population there is much more to this idea than meets the eye as I shall explain a common
00:34:32.160 misconception about Darwinian evolution is that it maximizes the good of the species that provides
00:34:38.400 a plausible but false explanation of apparently altruistic behavior in nature such as parents
00:34:43.760 risking their lives to protect their young or the strongest animals going to the perimeter of
00:34:48.000 a herd under attack thereby decreasing their own chances of having a long and pleasant life or
00:34:52.640 further offspring thus it is said evolution optimizes the good of the species not the individual
00:34:59.200 but in reality evolution optimizes neither to see why consider this thought experiment you
00:35:06.720 imagine an island on which the total number of birds of a particular species will be maximized
00:35:11.440 if they nested at say the beginning of April the explanation for why a particular data is optimal
00:35:16.160 we refer to various trade-offs involving factors such as temperature the prevalence of predators
00:35:21.680 the availability of food and nesting materials and so on suppose that initially the whole
00:35:27.040 population has genes that caused them to nest at that optimum time that would mean those genes
00:35:32.400 were well adapted to maximizing the max that would mean that those genes were well adapted
00:35:38.080 to maximizing the number of birds in the population which one might call maximizing the good
00:35:43.680 of the species now suppose that this equilibrium is disturbed by the advent of a mutant gene
00:35:49.600 in a single bird which causes it to nest slightly earlier say at the end of March
00:35:55.920 assume that when a bird has built a nest the species other behavioral genes are such
00:36:00.880 that it automatically gets whatever cooperation it needs from a mate that pair of birds
00:36:06.560 would then be guaranteed the best nesting site on the island an advantage which in terms of the
00:36:12.960 survival of their offspring might well outweigh all the slightest advantages of nesting earlier
00:36:19.280 in that case in the following generation there will be more March nesting birds and again
00:36:24.800 all of them will find excellent nesting sites that means that a smaller population than usual
00:36:30.800 of the April nesting variety will find good sites the best sites will have been taken by the
00:36:36.000 time they start looking in subsequent generations the balance of the population will keep shifting
00:36:41.840 towards the March nesting variants if the relative advantage of having the best nesting sites is
00:36:47.120 large enough the April nesting variant could even become extinct if it arises again as a mutation
00:36:54.160 it's hold will have no offspring because all sites will have been taken by the time it tries to nest
00:37:00.160 thus the original situation that we imagined with genes that were optimally adapted
00:37:05.360 to maximizing the population benefiting the species is unstable there will be evolutionary
00:37:11.040 pressure to make the genes become less well adapted to that function this changes harm the species
00:37:18.000 in the sense of reducing its total population because the birds are no longer nesting at the
00:37:21.840 optimum time it might thereby also have harmed it by increasing the risk of extinction
00:37:27.760 making it less likely to spread to other habitats and so on so an optimally adapted species
00:37:32.880 may in this way evolve into one that is less well off by any measure okay so I'll just pause
00:37:38.560 there this is a powerful way of explaining the selfish gene idea that Richard Dawkins popularized
00:37:45.920 so this idea of the selfish gene stands in stark contrast to other people who argue for group
00:37:52.560 selection or even species selection I think Stephen J Gould was one of the most famous proponents
00:37:58.560 that argued against Dawkins when it came to this concept of the selfish gene here David is using
00:38:04.960 this thought experiment about a bird that is that for the best of the species the bird should
00:38:14.000 be nesting sometime in April you know it's good weather and you know there's lots of food and so
00:38:18.400 on but if there was a mutation in the gene that controls when a bird nests such that the bird
00:38:26.080 didn't nest in April which is optimum for the bird but instead started nesting in March
00:38:30.720 then the birds would find there are more nesting sites especially if there's a limited number
00:38:37.040 of nesting sites and so if the mutant gene causes the bird an individual bird to start nesting
00:38:44.880 earlier then that bird might have offspring which is more likely to survive because there's less
00:38:51.200 competitors at that time so the I've got birds outside right now making noise so what can happen
00:38:58.400 then is that those particular birds have an advantage over the ones that are nesting in April which
00:39:05.120 are competing for food and so on and so the ones in March are able to have more offspring
00:39:10.880 and so if these birds start nesting earlier namely in March sometime then by the time the
00:39:16.880 April birds come around decide to nest perhaps so this this bird okay let's say it's able to
00:39:25.200 find a mate pretty quickly which has a random mutation in the gene that causes it to nest
00:39:32.960 such that it nests in March instead of April will have offspring that will also have
00:39:38.400 that variant of the gene and because in March if they're nesting in March and they're not
00:39:44.880 competing with other birds then the offspring are likely to survive more easily because the
00:39:52.880 parents aren't competing for nests with other birds so they have offspring which themselves
00:39:57.200 have the variant and so it goes on and so you end up with this situation where the birds are
00:40:04.560 nesting during March which is not optimal for the species and indeed when the April nesting bird
00:40:10.480 decide to nest in April all the nests are taken by the birds sort of nested in March
00:40:17.360 and this isn't good for the species because the optimal time by the terms of the thought
00:40:22.160 experiment is April that's where all the food is that's where just the ideal conditions are
00:40:27.600 March is not ideal but the gene itself the gene has been successful and it's pushed away the
00:40:36.320 gene that was useful for the species in favor of the selfishness of the gene itself the gene
00:40:43.840 itself is the thing that has persisted and it could cause the species of April nesting birds to go
00:40:52.400 extinct and then you'd essentially have kind of a new species you'd have March nesting species
00:40:58.080 which in the long run the March nesting species probably wouldn't be wouldn't thrive as well
00:41:02.960 and they wouldn't thrive as well because that's not the optimum time for these particular
00:41:07.680 bird species to nest I'll keep reading so back to the book if a further mutant gene then appears
00:41:15.600 causing nesting still earlier in March the same process may be repeated with the earlier nesting
00:41:21.360 genes taking over and the total population falling again evolution will thus drive the nesting time
00:41:27.840 ever earlier and the population lower a new equilibrium would be reached only when the advantage
00:41:33.120 to an individual bird's offspring of getting the very best nesting site was finally outweighed
00:41:38.000 but the disadvantages are slightly earlier nesting that equilibrium might be very far from what
00:41:43.440 was optimal for the species a related misconception is that evolution is always adaptive
00:41:50.480 that it always constitutes progress or at least some sort of improvement in useful functionality
00:41:56.800 which it then acts to optimize this is often summed up in a phrase due to the philosopher Herbert
00:42:02.000 Spencer and unfortunately taken up by Darwin himself the survival of the fittest but as the above
00:42:10.080 thought experiment illustrates that is not the case either not only has the species been harmed by
00:42:15.280 this evolutionary change every individual bird has been harmed as well the birds using any
00:42:22.160 particular site now have a harsh head life then before because they are using it earlier in the year
00:42:28.880 skipping a little what exactly has the evolution of those birds achieved during that period it is
00:42:34.400 optimized not the function of adaptation of ovarian genes with environment the attribute that would
00:42:39.120 have impressed pale but the relative ability of the surviving variant to spread through the population
00:42:44.960 an April nesting gene is no longer able to propagate itself to the next generation even though it
00:42:50.560 is functionally the best variant the early nesting gene that replaced it may still be tolerably
00:42:57.040 functional but it is fittest for nothing except preventing variants of itself from procreating
00:43:04.800 from the point of view of both the species and all its members the change brought about
00:43:10.560 by this period of evolution has been a disaster but evolution does not care about that
00:43:15.920 it favors only the genes that spread through the population so again my commentary here now wonderfully
00:43:23.360 succinct very well explains what the process of evolution by natural selection is in terms of
00:43:28.880 genetic selection it's not about which species will survive it's not about group selection it never
00:43:34.960 is it's about genes surviving okay skipping a little end back to the text David writes is it she
00:43:42.960 luck then that most genes do usually confer some albeit less than optimal functional benefits
00:43:48.880 on their species and on their individual holders no organisms are the slaves or tools
00:43:55.760 the genes used to achieve their purpose of spreading themselves through the population that is
00:44:00.960 the purpose that paleon even Darwin never guessed genes gain advantages over each other
00:44:07.040 and part by keeping their slaves alive and healthy just as human slave owners did
00:44:11.520 slave owners were not working for the benefit of their workers of their workforces
00:44:15.920 nor for the benefit of individual slaves it was solely to achieve their own objectives that they
00:44:21.520 fed and house their slaves and indeed forced them to reproduce genes do much the same thing
00:44:29.280 in addition there is the phenomena of reach when the knowledge in a gene happens to have
00:44:34.880 reach it will help the individual to help itself in a wide range of circumstances and by more
00:44:41.680 than the spreading of the gene strictly requires that is why mules stay alive even though they
00:44:47.600 are sterile so it is not surprising that genes usually confer some benefits on their species
00:44:53.280 and its members and do often succeed in increasing their own absolute numbers nor should it be
00:44:58.720 surprising that they sometimes do the opposite but what genes are adapted to what they do better
00:45:04.320 than almost any variant of themselves has nothing to do with the species or the individuals
00:45:09.280 or even their own survival in the long run it is getting themselves replicated more than rival
00:45:14.720 genes now we move directly to the next section which is an especially David Deutsch take on neodarwinism
00:45:22.400 so he's taking the work of Richard Dawkins step further David writes he's called the section
00:45:29.280 neodarwinism and knowledge and writes neodarwinism does not refer at its fundamental level
00:45:36.480 to anything biological it is based on the idea of a replicator anything that contributes
00:45:41.760 causally to its own copying for instance a gene conferring the ability to digest a certain type
00:45:47.920 of food causes the organism to remain healthy in some situations where it would otherwise we
00:45:52.960 cannot die hence it increases the organisms chances of having offspring in the future
00:45:58.560 and those offspring would inherit and spread copies of the gene ideas can be replicators too
00:46:04.720 for example a good joke is a replicator when lodged in a person's mind it has a tendency to
00:46:09.200 cause that person to tell it to other people thus copying it into their minds Dawkins coined the
00:46:14.880 term memes runs with dreams dreams for ideas that are replicators most ideas are not replicators
00:46:21.760 they do not cause us to convey them to other people nearly all long lasting ideas however
00:46:26.880 such as languages scientific theories and religious beliefs and the ineffable states of mind
00:46:31.520 that constitute cultures such as being British or the skill of performing classical music
00:46:36.080 and memes or memeplexes collections of interacting memes i shall say more about this in chapter 15
00:46:43.360 the most general way of stating the central assertion of the neodarwinian theory of evolution
00:46:48.240 is that a population of replicators subject to variation for instance by imperfect copying
00:46:53.200 will be taken over by those variants that are better than their rivals causing themselves to be replicated
00:46:57.920 this is a surprisingly deep truth which is commonly criticized either of being too obvious to
00:47:03.520 be worth stating or for being false the reason i think is that although it is self-evidently true
00:47:09.840 it is not self-evidently the explanation of specific adaptations our intuition prefers explanations
00:47:16.160 in terms of functional purpose what does a gene do for its holder or for its species but we
00:47:23.040 have just seen that genes generally do not optimize such functionality so the knowledge embodied in
00:47:28.880 genes is knowledge of how to get themselves replicated at the expense of their rivals
00:47:34.480 genes often do this by imparting useful functionality to their organism and in those cases
00:47:40.800 their knowledge incidentally includes knowledge about that functionality functionality in turn
00:47:45.520 is achieved by encoding into genes regularities in the environment and sometimes even rule of
00:47:50.560 thumb approximations to laws of knowledge in which case the genes are incidentally encoding that
00:47:55.280 knowledge too but the core of the explanation for the presence of a gene is always that it got
00:48:00.640 itself replicated more than its rival genes non-explanatory human knowledge can also evolve in an
00:48:06.880 analogous way rules of thumb are not passed on perfectly to the next generation of users
00:48:11.840 and the ones that survive in the long run are not necessarily the ones that optimize the
00:48:15.680 ostensible function for instance a rule that is expressed in an elegant rhyme may be remembered
00:48:21.280 and repeated better than one that is more accurate but expressed in ungainly prose also
00:48:26.800 no human knowledge is entirely non-explanatory there is always at least a background of assumptions
00:48:31.680 about reality against which the meaning of a rule of thumb is understood and that background
00:48:36.800 can make some false rules of thumb seem plausible explanatory theories evolve through a more
00:48:43.120 complicated mechanism accidental errors in transmission and memory still play a role but a much
00:48:49.040 smaller one that is because good explanations are hard to vary even without being tested and hence
00:48:55.760 random errors in the transmission of a good explanation are easier for the receiver to detect
00:49:01.440 and correct the most important source of variation in exponatory theories is creativity for instance
00:49:07.280 when people are trying to understand an idea that they hear from others they typically understand
00:49:11.680 it to mean what makes most sense to them or what they are most expected to hear or what they fear
00:49:17.840 to hear and so on those meanings are conjectured by the listener or reader and may differ from what
00:49:23.360 the speaker or writer intended in addition people often try to improve explanations even when
00:49:29.040 they have received them accurately they make creative amendments spurred on by their own criticism
00:49:34.320 if they then pass the explanation onto others they usually try to pass on what they consider
00:49:38.560 to be the improved version so this is one of those sections where I really need to pause
00:49:43.120 embedded amongst the text the text which is great is this real gem I don't know the
00:49:48.960 pop has spent much time trying to explain the psychology of learning but here David really has
00:49:56.080 gone to the heart of the matter he's brought to bear popularian epistemology to the process of
00:50:01.840 learning people are not taking this seriously that are interested in the question about how people
00:50:07.520 learn or trying to maximize learning let's say so I'm never going to make a habit of rereading
00:50:13.440 things after all people can just rewind the video but this is so important I think I need to
00:50:18.000 emphasize it again so David's talking about understanding we may as well say learning here so let
00:50:24.400 me just read let me just read those very few sentences again because they're very dense they have
00:50:29.440 this amazing idea he writes when people are trying to understand an idea that they hear from others
00:50:37.760 so for example from a lecturer or from a teacher or from a parent or from a friend you're just
00:50:42.320 trying to understand something how is it that you learn well what he says here is that people
00:50:50.880 typically understand that the listener typically understand it the thing that they're trying to learn
00:50:55.920 they typically understand it to me what makes most sense to them or what they are most expecting
00:51:02.240 to hear or what they fear to hear and so on okay so it could be any number of things you have
00:51:08.000 these expectations about what you're about to hear and that's what you understand you can't just
00:51:15.280 gain understanding from the message that's coming to you you have to bring your understanding to
00:51:20.880 the message those meanings are conjectured by the listener or reader and may differ from what the
00:51:27.200 speaker or writer intended so you're trying to teach someone something you're trying to help
00:51:33.680 someone learn in some way it's not a matter of you speaking ever more clearly or ever more loudly
00:51:43.360 or it's not a matter of your intentions of what you're expecting the person to learn it's a matter
00:51:49.680 of what they're expecting to hear which is a profound idea people often try to improve explanations
00:51:58.000 even when they have received them accurately they make creative amendments spurred
00:52:03.680 by their own criticism I've personally experienced this a lot that I can explain something
00:52:10.880 and the listener does a far better job than I could ever have done in explaining that particular
00:52:17.440 concept because they've understood it in a way that is very different to what I understand it
00:52:25.520 and their way is more parsimonious their way is free of the kind of errors that I was bringing to
00:52:30.640 my explanation so it's absolutely true it's the expectations of the person that's doing the
00:52:36.400 learning that shapes what it is they understand a particular concept to be you can't pass on the
00:52:44.560 concept you can only really pass on the message you can attempt to transmit but the receiver
00:52:52.880 is the thing that's doing the error correction I'm gonna continue reading but he's about to speak
00:52:59.920 to write a little bit more about a little bit more about understanding but just to link
00:53:05.440 that last paragraph with the next one it does really seem to me to be the case that
00:53:11.840 when people try and understand each other what each other is saying that if I use certain words
00:53:18.640 in perfect English and you are a perfectly fluent English speaker as well that what you hear might
00:53:26.800 be a certain set of words which go into your ears converted into electrical signals passed into
00:53:33.200 your brain then into your mind what your mind then does is an absolute mystery for the most part
00:53:42.400 but your way of viewing the world even though we're using exactly the same language could be
00:53:47.840 vastly different that what you understand certain words to actually mean could be quite different
00:53:54.320 to what I understand them to me and so an act of translation goes on that when I use a word
00:54:00.320 which labels a particular concept although you understand the word it could label it
00:54:05.520 and ever so slightly different or perhaps a completely different concept in your mind
00:54:11.120 and so then when you respond to me you're responding to the concept you understand the word
00:54:17.680 to label and so when I hear your response I'm assuming that the words that you're using now which
00:54:23.360 could be exactly the same word that I've just used in conveying something to you is actually
00:54:27.920 labeling a different concept than the one that I thought it was labeling so as proper would say
00:54:33.120 you cannot speak in such a way as to not be misunderstood everyone could be speaking precisely
00:54:38.480 the same language perfectly accurately perfectly fluently but still talking about different
00:54:44.800 things even though you're using the same words I don't know how common this is but I do think
00:54:49.840 it's an important problem that we have in attempting to understand each other human beings are
00:54:55.920 mysterious as Jared Lanier would say we infinite wells of mystery can just keep on discovering
00:55:01.280 more and more and more about people and we don't seem to get to the end I think problems are
00:55:06.160 soluble but I do think he has a point here that because of creativity and creativity is kind of
00:55:12.960 this infinite thing with infinite reach that perhaps understanding someone else and just like
00:55:19.040 perfectly understanding anything it's impossible but in particular understanding something with
00:55:26.400 arguably infinite complexity like a human mind is even more challenging but exciting as well
00:55:33.760 okay continue unlike genes many memes take different physical forms every time they are replicated
00:55:40.640 people really express ideas in exactly the same words in which they heard them they also translate
00:55:46.080 from one language to another and between spoken and written language and so on yet we rightly
00:55:50.800 call what is transmitted the same idea the same meme throughout thus in the case of most memes the
00:55:57.360 real replicator is abstract it is the knowledge itself this is in principle true of genes as well
00:56:04.160 biotechnology routinely transcribes genes into the memories of computers where they are stored in
00:56:09.200 a different physical form those records could be translated back into DNA strands and implanted in
00:56:14.640 different animals the only reason this is not yet a common practice is it is easier to copy the
00:56:19.840 original gene but one day the genes of a rare species could survive its extinction by causing
00:56:25.200 themselves to be stored on a computer then implanted into a cell of a different species I say
00:56:30.800 causing themselves to be stored because the biotechnologist would not be recording information
00:56:34.960 indiscriminately but only information that met a certain criterion such as gene of endangered species
00:56:40.800 the ability to interest biotechnologists in this way would then be part of the reach of the
00:56:45.760 knowledge in those genes so both human knowledge and biological adaptations are abstract replicators
00:56:51.680 forms of information which once they are embodied in a suitable physical system tend to remain so
00:56:57.440 while most variants of them do not the fact that the principles of neodarwinist theory are
00:57:04.240 from a certain perspective self-evident has itself been used as a criticism of a theory for instance
00:57:10.320 if the theory must be true how can it be testable one reply often attributed to helldane is that
00:57:16.800 the whole theory would be refuted by the discovery of a single fossilized rabbit in a stratum of
00:57:21.520 Cambrian rock however that is misleading the import of such an observation would depend on what
00:57:27.360 explanations were available under the given circumstances for instance miss identifications of fossils
00:57:32.720 and of strata have sometimes been made and would have to be ruled out by good explanations before
00:57:37.760 one could call the discovery a fossilized rabbit in Cambrian rock even given such explanations
00:57:45.520 what would have been ruled out by the rabbit would not be the theory of evolution itself
00:57:49.520 but only the prevailing theory of the history of life and geological processes on earth
00:57:54.000 suppose for instance that there was a prehistoric continent isolated from the others on which
00:57:58.400 evolution happened several times as fast as elsewhere and that by convergent evolution a
00:58:03.520 rabbit-like creature of all there during the Cambrian era and suppose the continents were later
00:58:08.080 connected by catastrophe that obliterated most of the life forms on that continent and submerged
00:58:12.320 their fossils the rabbit-like creature was a rare survivor which became extinct soon afterwards
00:58:17.600 given the supposed evidence that is still an infinitely better explanation than for instance
00:58:22.800 creationism or Lamarchism neither of which gives any account of the origin of the apparent
00:58:27.120 knowledge in the rabbit so what would refute the Darwinian theory of evolution evidence which
00:58:33.200 in the light of the best available explanation implies knowledge came into existence in a different way
00:58:39.680 for instance if an organism was observed to undergo only or mainly favorable mutations as
00:58:45.280 predicted by Lamarchism or spontaneous generation then Darwinism's random variation postulate
00:58:51.120 would be refuted if organisms were observed to be born with new complex adaptations for
00:58:56.720 anything of which there were no precursors in their parents then the gradual change prediction
00:59:02.240 would be refuted and so would Darwinism's mechanism of knowledge creation if an organism was born
00:59:08.400 with a complex adaptation that is survival value today yet was not favored by selection
00:59:13.280 pressure in its ancestry say an ability to detect and use internet where the forecast
00:59:17.440 to decide when to hibernate then Darwinism would again be refuted a fundamentally new
00:59:23.280 explanation would be needed facing more or less the same unsolved problem that paleon Darwin faced
00:59:29.360 we should have to set about finding an explanation that worked okay so this is this
00:59:34.960 some might think it's a controversial point I don't know I don't know that matters I make a
00:59:41.200 big deal as many people interested in the philosophy of science do about the line of demarcation
00:59:45.680 between science and non-science when it comes to this question about neo Darwinism Darwinism broadly
00:59:53.200 speaking and whether or not it's falsifiable given that David has just said well rabbits in the
00:59:59.760 pre-cambrian would not falsify the theory and then asked the question well what would
1:00:05.680 well evidence that would suggest that you only ever had favorable adaptations so that's possible
1:00:12.160 but some people still argue that well perhaps it's just this thing called a research framework
1:00:18.080 so you know some people argue about whether or not the theory of evolution by natural selection
1:00:24.160 Darwinism neo Darwinism whether it's a scientific theory or actually something deeper than a scientific
1:00:29.520 theory sometimes called a research program now I don't think it really matters ultimately
1:00:35.840 whether it's the framework within which we do biology or whether it is a scientific explanation
1:00:42.240 subject to the usual test the usual experimental test that we can perform on any scientific theory
1:00:49.520 just so happens coincidentally I'm reading a book by the philosopher and or biology philosopher
1:00:57.040 Michaelis Michael Professor of Michaelis Michael at University of New South Wales here in
1:01:02.320 Australia he's written a book just recently called evolution by natural selection confidence
1:01:08.080 evidence and the gap now Michaelis has a few problems with pop-up and with falsificationism
1:01:13.920 and indeed to some extent is a proponent of Stephen J Gould's view good to read people who you
1:01:19.440 disagree with but I just wanted to take a moment just to read his section here of his book
1:01:25.680 it's subtitled is evolutionary theory falsifiable so let me just read what Michaelis has written
1:01:31.760 he writes the question we started with is is evolutionary theory science takes on a
1:01:38.080 period guys as is evolutionary theory falsifiable but this is too coarse grain to be answered
1:01:44.640 there are many different evolutionary theories we can can consider and we can ask of each of
1:01:50.080 them whether it is falsifiable so Michaelis's claim is that the different evolutionary theories
1:01:55.760 might be considered to be is the theory that evolution has taken place firstifiable is the theory
1:02:02.560 that the human chin evolved falsifiable is the theory that evolution has involved natural selection
1:02:09.040 falsifiable is the theory that the human chin evolved through natural selection
1:02:13.280 falsifiable the theory that evolution has taken place is a historical theory it says
1:02:19.280 that the biological world has evolved it says that the biological world has changed at the time
1:02:24.320 is it falsifiable? To be falsifiable is to be able to specify an observation that would refute
1:02:29.280 the theory. It might be thought that this would not be falsifiable. However, a moment's reflection
1:02:34.320 should convince you that you can imagine possible evidence that would refute the theory that
1:02:37.920 evolution has taken place. In this case, it is easy to find such a piece of possible evidence.
1:02:43.360 What if the fossil record never revealed any changes? Were the fossil record to be just like
1:02:49.040 the present organisms, then the theory that there has been biological evolution would be falsified?
1:02:55.040 In fact, the fossil record does show that at different times the biological world has been exemplified
1:03:00.720 by different organisms. Therefore, this theory is in fact falsifiable. We can specify a
1:03:06.480 feuding observations that would have led to the theory being rejected. The observations did not
1:03:11.200 take place, but that does not mean the theory is not falsifiable, but only that it is not yet
1:03:16.960 falsified. What about the theory that the human chin evolved is falsifiable? This theory is also
1:03:23.920 a historical theory. It says that at one time, organisms existed with no chins and that later descendants
1:03:30.240 had chins. There are issues with deciding which types of organisms are ancestral to which,
1:03:34.720 but one thing we could predict, so have seen in the fossil record that would lead to this theory
1:03:39.520 being rejected, is if all species in the lineage allied with the hominin lineage had chins. Indeed,
1:03:46.320 we could have falsifying evidence were chins to be found in the hominin lineage regardless
1:03:51.360 of whether they are directly ancestral to our species. Just as we might say they have been
1:03:55.520 changes to the heart in humans where we define that humans evolve features or structures
1:03:59.840 novel to their hearts, we do not say that the heart evolved in humans when all vertebrates have
1:04:04.000 hearts. So the theory that the chin evolved in humans is falsifiable. Again, there are observations
1:04:10.080 we could have observed that would have told against that theory. It is important to note that saying
1:04:16.080 that a theory is falsifiable does not mean that if it were false, then there would in fact be
1:04:21.040 some observable evidence that tells you the theory is false. There may be many circumstances in
1:04:25.280 which you cannot tell whether a particular theory is false and only a few in which you can tell
1:04:29.440 the theory is false. Such a theory is nevertheless still falsifiable. What about the theory that
1:04:33.920 natural selection has been involved in evolution? This is a historical theory. Once again,
1:04:39.040 it is about what happened in the past, but it is not just about what happened. It is about
1:04:43.840 why what happened happened. Saying that something evolved by natural selection involves identifying
1:04:48.240 the mechanism that drove that change. Is that visible? Is it important to see that it is not visible?
1:04:54.320 In fact, there is a general issue with causation. What we aspire to in science is more
1:04:58.720 than just a catalog of what happened when. Although finding out what happened when is often hard
1:05:03.360 enough. In scientific endeavors, we do try to discern why things happened. The causal explanations.
1:05:09.920 Since Hume, we have known that this is very difficult. We see constant conjunctions easily,
1:05:15.360 but finding causation is much more difficult. Or rather, getting clear what we need to establish
1:05:19.760 to have established the causal link is the difficult question. One idea coming from Hume himself
1:05:24.800 is about what happens when we manipulate the system. Hume famously gives two versions of the
1:05:29.120 nature of causation. The first is entirely empirical. It is just that A causes B when A type of
1:05:34.080 ends are constantly conjoined with B type of ends. And A and B are spatiotemporally contiguous. And
1:05:39.760 we come to expect B when we perceive A. The second account involves counterfactuals since just
1:05:44.480 that A causes B if our spatiotemporally contiguous and manipulating A manipulates B. Therefore,
1:05:51.520 well, A not to occur then B would not either. Exploring the science, metaphysics and epistemology
1:05:56.480 of causation is not a small topic. It may be enough to say that finding the constant conjunctions
1:06:01.600 is hard enough in science, finding causal relations is hard to steal. However,
1:06:06.080 here a strange fact needs to be highlighted. This theory that we have, this theory that we have
1:06:12.720 decided is not falsifiable, is in fact that conclusion of Darwin's key argument for natural
1:06:17.760 selection. Darwin argued for this conclusion from two premises that we saw were empirical
1:06:22.560 and falsifiable. The first that there is an excess of young relative to breeding individuals.
1:06:27.040 The second is that there is variation and that the variations are heritable.
1:06:30.160 Each of these was empirically testable even in Darwin's day and his evidence for both was copious.
1:06:36.240 Darwin also used another premise that amounted to an analytic claim. If any variations help
1:06:41.440 their barriers in the struggle for existence, then these will be fitter and have a higher tendency
1:06:46.080 to survive. From these three, together with a law of large numbers type hidden premise,
1:06:51.360 he derived the conclusion that natural selection would have taken place. Okay, so that's what
1:06:56.320 Michaela's Michael from Sydney happens to say about evolution by natural selection and whether
1:07:02.720 it's falsifiable. Of course, I would have some issues with the way he's presented what
1:07:08.400 causation is there. It sounds inductivist to me. Nevertheless, as he admits, there's really a
1:07:16.720 problem there with trying to understand this concept of causation. He does admit that science is
1:07:22.240 very much about explanation. I don't know if he's aware of what hard to vary is about.
1:07:26.960 The book is an interesting one. There's a lot there about falsification and science.
1:07:32.400 As I say, I don't necessarily agree with it all. Nevertheless, it's very interesting. If you
1:07:38.240 can get hold of the book, it's not a very long book. It's 140 something pages,
1:07:44.480 but going back to the beginning of infinity now. The next section is about fine tuning and I'll
1:07:48.720 leave that until next time. But what was really interesting here in this part is the symmetry between
1:07:55.440 the way in which human knowledge is constructed, especially explanatory knowledge via this
1:08:00.960 process of conjecture and refutation or guessing in criticism or creation and creativity in
1:08:07.840 criticism and biological evolution, where you have random mutations and then selection of those
1:08:15.200 or variation and selection. They mirror one another, not exactly the same, in particular.
1:08:20.960 The kind of mechanisms that allow us to create explanatory knowledge are intelligently designed.
1:08:27.840 People have minds, they have intentions, they have free will, and so they're able to choose amongst
1:08:34.080 different ways in which they might improve knowledge. This idea of creativity, of the ability to
1:08:40.320 create explanatory knowledge has, I think, a deep connection to the concept of free will,
1:08:45.680 and whether or not we have free will, even given determinism. Because the growth of knowledge
1:08:51.120 is inherently unpredictable, and we don't know what problems are going to come next. So we don't
1:08:56.320 know where we're going to direct our minds. I think that's where we'll live for today.
1:09:00.640 I'll look forward to the next part at some about fine tuning, as I've already said, and perhaps
1:09:05.520 in a few days, possibly a week, I'll be able to get to that. See you later.
