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He answers this question by saying I quote I believe that animals are descended from at most only four of five progenitors and plants from an equal or lesser number. He then goes out goes on to say I quote analogy would lead me one step further namely to the belief that all animals and plants I descended from some one prototype. But analogy may be a deceitful God. I am called. He did not have to rely on analogy for strict ad hair if he had been sed his and if he had hinted at he had strictly to his own principle of phylogenetic continuity that should have led him to postulate as did JP Robinetta before him a single prototype or per Genesis for all living organisms. Both plants and animals. For if there were as many as two original progenitors one for all forms of animal life and one for all forms of plant life it would mean that the plant and animal kingdoms are separated by a real and perhaps radical difference in kind not by an apparent difference in the kind that mass a continuum of degrees in which gaps have occurred.
I cannot emphasize or overemphasize the basic point and I'm going to make a polyphyletic Arjen of life is incompatible with the principle of phylogenetic continuity and Darwin was a little bit too timid to say that. I turn now to the post Darwinian modifications in his theory of speciation. The most important change in post Darwinian theory involves a shift from natural selection and the extinction of in the media varieties as the explanation of the gaps in the continuum that are indispensable for the origin of species. Where Dahl used the extinction of the the media varieties to explain the genetic isolation of the remaining extreme varieties the post Darwinian theorists with greatly improved genetics and much more paleo logical evidence used geographic barriers. As the explanation of genetic isolation responsible for the formation of new species.
It is now generally accepted that most speciation is allopatric in different countries different areas to parts of the country. The result of geographical separations that are interbreeding between varieties of the same species with the result that the gene pools the gene pools of the spatially separated varieties become isolated from each other. In the exceptional cases of sympatric speciation the Arjen of new species in the same host area or locality. The explanation given is polyploidy. And explosive genetic change unknown and perhaps probably unimaginable to dog. The modern theory has distinguished three or four different types of speciation and has given us a different explanation of the factors productive other. The central point remains the same. Namely that distinct species are
genetically isolated populations between which breeding and interbreeding has become impossible arising except in the cases of polyploidy from varieties between which in the breeding was not impossible but between which it had was prevented and has now become impossible. Modern theorists with more assurance than Darwin could manage treat distinct species as natural can not as man made class distinctions. Ernst Mayr and Julian Huxley. Even going so far as to regard speciation as introducing some discontinuity into nature since they subordinate this discontinuity of species to the basic phylogenetic continuity of the evolutionary process it is clear that they do not mean discontinuity in the sense that excludes the possibility of a debate is instead of saying that speciation introduces just continuity. They should have said that speciation introduces gaps or interruptions in the
continuity of nature. Another important change in postal winning in theory is the departure in a number of exceptional cases from strict adherence to the rule that Nature does nothing by jumps. Simpson George Gaylord Simpson and Theodore dock chancy speak of quantum jumps in evolution which in fact. Are cases of solitary speciation where it's solitary having him her sort by jumps. This involves breaks in the developmental continuity of evolution just as ordinary speciation introduces gaps or breaks into the continuum of coexisting populations. Quantum evolution or breaks in the evolutionary continuity occur according to the OP chancy I quote. When the differences between the ancestors and the descendants increase so rapidly that they are perceived as differences in culture. What are these differences in conduct that are produced by any of the diverse
types of speciation recognized by modern theory. Are they all only a parrot. On the wall may they also include some that are real differences in kind even though to be consistent with phylogenetic continuity. They must obviously be some official not radical differences in God. Let me answer that question in the first place. It is necessary to reiterate that the post Darwinian theory of evolution and speciation does definitely screwed radical differences in kind as emphatically as does Darwin's theory for such differences are plainly incompatible with developmental continuity which even when it involves breaks or quantum jumps cannot be equated with the basic discontinuity coff of morality called for by radical differences in kind. Who what is much more important and what I think should give you a great deal of illumination is this inside the leading contemporary theorists top Shand scary
man. Huxley agreeing that there would be no species at all if interbreeding were totally unrestricted and all possible genetic company combinations or geno types were simultaneously really realized in co-existing or extent living organisms or phenotypes such genetic swapping would result in nothing but in a ray of individual differences only individuals all different. Only in degree. Let me quote two passages from the top chancy ass just asks the US to consider. I quote an imaginary situation a living world in which all possible gene combinations are represented by equal numbers of individuals. Under such conditions no discrete group of forms can to cause the variability would become
a perfect continuum. And he goes on to say of this actual world I quote. If the representatives of different groups interbreed at random all the gene combinations that are now rare are absolutely produced. Given a sufficient number of individuals within a few generations from the start of random breeding that would mean a breakdown of the separation of groups and an emergence of continuous variation over a part of the field. If all the organisms were to breed freely. A perfect continuum postulate above would result. This one apparently the can to the conclusion that the difference in kind that separate species is only apparent not real the result of gaps in the Continuum produced by barriers to interbreeding. For if those gaps were filled by completely random interbreeding the breaks in the continuum of blue would be removed and the apparent differences in kind would reprove would be replaced by
differences in degree. Though this may be the case and I take it to be the best scientific opinion asserts that it is the case with respect to all species of animals and all species of plants it is not entirely clear that it also applies to the distinction in common between the whole plant kingdom and the whole animal kingdom. If these stem from two original preventives rather than one the difference in kind would have to be real probably radical. Even if these stem from a single prototype. Single original prototype the difference in kind might be real though to preserve the developmental continuity of evolution would have to be only a superficial difference in kind arising from a critical threshold in the basic or underlying continuum of degrees of material complexity. This takes us back to the question about men bringing the foregoing analysis to bear on that question.
We get the following hypothetical answers. First if man is an animal species and if that species belongs to the animal kingdom in exactly the same way as do all other animal species then the human species differs from other closely related species. By no more than an apparent difference in kind which is really a difference in degree that is masked by the absence of the immediate thought. The second alternative is that if man. Opposite alternative is dealing with them still is possible. If man then one animal differs from all members of the animal kingdom as they in turn differ from all members of the plant kingdom then even within the framework of evolutionary development the different tree man. And other animals may be a real difference in kind. Superficial of course not radical. We need not be content with these hypothetical answers evolutionists from Darwin to the present day have given this categorical answer to the question about man.
Let's turn to them now. Together with the evidence and reasoning in support of them I turn first to the position of Dolly and of his contemporaries position he takes on man in the light of evolutionary facts and theories in the middle of the 19th century a postponed for the moment to the right of all of the view rather. Considerably all view that has happened since Darwin's day. Darwin addressed himself to the question about May and quite hesitantly almost reluctantly that the set of man was published in 1871 12 years after they are two species in 1859. In his introduction to the descent of man he acknowledges that other evolutionists had applied evolutionary theory before him to the origin and nature of man he mentioned to mock whoever they didn't by many is more than 60 in fact 18 0 9. He also mentions among his more immediate contemporaries the writings of Wallace Huxley Lyell and heckle and express a special
indebtedness to heckles discussion of the genealogy of man in a book published in 1868 three years before the descent of man. The relation of down to three of these contemporaries deserves a brief further comment. Lyell the great geologist great book titled The principles of geology in the closing chapter of a less great book called the antiquity of man 1863 to Mars. I quote demurs to the assumption that the hypothesis of variation and natural selection obliges us to assume that there was an absolutely insensible passage from the highest intelligence of the inferior animals to the improvable reason of man that says lie out may have been accomplished by a leap nature. I quote. Nature may have cleared that one down. The space which separated the highest stage of animal intelligence from the first and lowest form of human reason. That sentence sense I just read you down
remark makes me groan. And well it might. For deny this principle that Nature does nothing by jumps. Wow ass. WALLACE First in a paper published in 1864 and Morrow tatic Lee in a paper published 1869 deny that the theory of evidence speciation by natural selection and the extinction of the dimity varieties could explain the origin of man. He did not think there was sufficient time for this to take place and he was puzzled by the absence of fossil evidence is the kind of fossil evidence is that he thought we needed to support Darwin's theory. This led to a serious rift between Darwin and his closest colleague in the development of the Theory of Evolution on the other hand. Darwin could draw support from the views of another of the subjects T.H. Huxley who in Father of Julian Huxley who in 1863 published a book of essays on man's place in nature. Huxley took the position letter to be taken by dollars. That man in all
his mental faculties differs only in degree from the anthropoid apes and the other higher mammals that we also concedes somewhat inconsistently. That man alone ever see that word alone it's a dangerous word because. Whatever alone means a devise difference in degree that man alone possesses the marvelous endowment of intelligible in rational speech. That was a quote Huxley also devotes one of his essays to the fossil remains of early man and discusses the Aengus skull and the neanderthal skull whereas Darwin in his handling of the subject makes no references no references at all to these fossil remains that were available to him as well as to Huxley. Let me turn to the thesis an argument of the descent of man because that book is to understand how Darwin reasoned there is very instructive for our purposes in this consideration. Let me pick close attention to Darwin's motive argument.
He lacked he lacked the rich and varied fossil finds of later paleoanthropology. And he obviously regarded the tour of the human skull as discussed by Huxley as insufficient to support his thesis. But man's Arjen from a remote ancestor common to the living human species and the extant species of apes. He therefore argued entirely from the comparison of the behavior of living man with the behavior of the living apes and other acts to extend species of animals especially the higher mammals. His argument had to take the form of establishing the proposition that the behavioral differences between man and other animals indicate that the difference in their mental powers is only one of degree. In the light of all the comparative evidences that he's able to marshal he thinks he is justified in concluding. I quote the difference in mind between man and the higher animals great as it is is certainly one of degree not a cop. And he added I quote a
difference in degree. However great does not justify isn't placing man in a distinct Kingdom. Like Huxley he concedes that rational speech is peculiar to man but he qualifies this modern Huxley does by pointing out in sipping it and rudimentary forms of expression and communication other animals an addition he explicitly degree's with Max below that man's use of language implies the power of forming general concepts and that since no animal appears to possess this power there is a real and perhaps radical difference in kind between men and other animals. Darwin says and I quote With respect to animals. I've already endeavored to show that they have this power. Power of conceptual thought at least in a rooted incipient degree. Though in one place he attributes manned man's development of articulate speech to his intellectual powers. More more usually he explains man's intellectual superiority as manifested by his
linguistic performances by reference to the superiority of his brain in size and complexity. A difference in degree only from other animals. This is a terribly important point. I mention this because even if one were to say that man's exclusive possession of articulate speech made is different from other animals a real difference in can we can imagine Darwin countering this by saying that if it is real it is that most of the fish will based on a critical threshold in the continuum of degrees in brain size and complexity. The reason why Darwin had to argue in this way should be perfectly plain if he had conceded if he had conceded the possibility then man might really different con and could not shout as of his day in his age he could not show that this was only a superficial difference in kind. He could not then support his thesis with the human species originated in the same way that all other animal species have
by descent with modification from a common ancestor accompanied by the extinction of intermediate arrives. The only view of man's difference compatible with this theory is with his theory of the R Arjen is a difference of degree indeed in degree part most an apparent difference in kind with an apparent difference in kind arises solely from the absence of the medians. A gap in the continuum of degrees. Hence Darwin argued in the light of all the comparative evidences he could cite that the mental powers of man differ only in degree from those of other animals but because of the absence of fossil remains. He also had to hypothecate without sufficient evidence. The earlier existence of forms intermediate between man and apes. The fact that they're that these are now extinct explains the breaks or gaps in the continuum that should connect man and the apes. These
gaps or breaks do not although Darwin's view that man and the apes have a vowel from a common ancestral form by a continuous process of descent without gaps or jumps. Now before I turn to the fossil evidence of Martin Paley when he went for apology they make three comments on Darwin's position and mode of argument. First the principle of phylogenetic continuity center of the theory of evolution and supported by a vast array of data and controls all of Darwin's reasoning. If comparative evidence with respect to human and animal behavior had shown that man different radically in kind from other animals Darwin would not have concluded that the principle of continuity was false or that it did not apply to the origin of all other animal species. He would have to conclude instead that man was the one or rare exception that the argot of the human species could not be explained in the same way as the origin of all
other species. However thinking as he did at the comparative evidence showed only difference in degree. Darwin felt justified in applying the principle of phylogenetic continuity and his theory of speciation to the origin of man. Second it is of the utmost importance to observe the direction of Darwin's reasoning here and insist that he does this once his reasoning is not from a hypothesis about man's origins based on fossil evidence his to a conclusion about man's nature and man's difference. On the contrary his line of reasoning is from a conclusion about man's nature and difference based on comparative evidence of human animal behavior to the support of though not the individual proof of a hypothesis about man's origin. That is his speciation and speciation is like that of all other animals. And my third point is that the effect of Darwin's Ascent of Man
is best summarized by the remark of William Graham in 1881. I quote That man is an animal is the great and special discovery of natural science in our generation as 1881. Read one way. This is a very strange remark indeed with the possible exception that they caught. Who ever deny that man was an animal with that one exception from they come from the Greeks to Kant and Hegel. Every philosopher who held that man differs radically in kind from other animals also asserted that man is an animal. A rational animal but an animal nonetheless. What then is the meaning of William Graham's remark that this great Darwin changed the whole picture thing by making man an animal it is simply the meaning is this that man is a brute animal. All that there is no radical difference in kind among animals between those that are rational and those that are not rational therefore of groups. What Graham is saying in shot is that
Darwin overthrew the prevailing view at the world of living things is divided into three kingdoms plants brute animals and rational animals all men animals share with plants the common characteristics of all living things. But we do not say therefore that animals are plants and hence the fact that man share with animals that men share with animals the common characteristics of animal life. Need not leave is to say that men are brutes unless we mean to deny as Darwin did name to deny the existence of a radical difference in time between men and other animals. I would like to consider with you. The evidence the relevance of paleoanthropology since Darwin say that they word bothers you all it means is the study of the fossil species of man. Tell you the logical evidence about man is opposed to the anthropology of the extant living species of man. And if I keep on saying paleoanthropology I know that these anthropologists study the prehistoric the fossil species
the discovery of fossil types of man or man like organisms other than the two skulls known in Darwin's time. The australopithecine fossils put the kind fossils from South Africa in the early Pleistocene Strattera about a million years ago the fossil remains of various types of Pithecanthropus Erectus from Java from Pekin from Heidelberg in the middle Pleistocene strata of about five hundred thousand years ago. The Swan scums skull found in a London dating back to about 250000 years ago. The Neanderthal fossils from Germany and somewhat later but related fines can become El Palestine. In solo Java and in revision dating back to about one hundred twenty thousand two hundred fifty thousand years ago and the Coleman Young and many similar fossils that dating back to 35000 to 50000 years ago represent the immediate ancestors of late Paleolithic neolithic and historic
man. All these discoveries would seem to confirm Darwin's hypothesis of man's evolutionary descent and to confirm his conjecture that the missing types in the developmental picture would be found. It would fill in the gaps in the Continuum. What I just said. The finding of the missing legs filling in the gaps in the continuum is the usual interpretation of the post Darwinian findings in paleoanthropology. But in fact a closer examination of the matter shows. On the contrary that modern paleoanthropology that part's Shockley from Darwin's theory Shockley our parts and several striking respects. Let me say at once that all respected contemporary anthropologists agree with Dogman about the evolutionary descent of man and about the Arjen of the human species by exactly the same processes that are responsible for the
speciation of all other living things. Darwin in the absence of fossil remains was forced to argue in support of his theory of man's Arjen by trying to establish the proposition from comparative behavioral evidences that man and other animals differ only in degree. In shock contrast to that contemporary anthropologists regard their rich a ray of fossil finds as sufficient confirmation of man's phylogenetic continuity with earlier animal forms so that they need not support that theory of man's origin by trying to show that man differs only in degree from other animals. On the contrary having the various fossil specimens to interpret and explain contemporary anthropologists must try to show. That all the members of the family home in a die all fossil as well as living types of man. Really different time from the other two most closely related family groups in the primate order
The Hi-Lo Bata die. That's the given and the punji die the orangutang the chimpanzee and the gorilla. For if the contemporary anthropologists want to follow Dolly in thinking that man differs only in degree from non male then they could not classify the fossil specimens into those that belong to the hominid family and those that belong to the Punjab family. The fossil of a living species of eight. In all four of them to point a finger at the time and place where human life begins. There was be able to draw a sharp line between human and non-human and to draw out they have to view man as really differing in kind from one man not just in degree. This is nicely confirmed by the fact that Darwin in the light of his own insistence upon difference only in degree writes I quote in a series of forms graduating insensibly that is by slight differences in degree from some ape like creature the man as he now exists it would
be impossible to fix on any definite point where the term man ought to be used and to that tell given telling sentence he adds. But this is a matter of very little importance. It was of very little importance to him. He had no fossil remains to classify but it was of the greatest importance. It is crucial for contemporary paleoanthropologist who try to or not and classify the fossil specimens of those that represent extant extinct species in the genus homo or at least in the family home in a dye as contrasted with those that reason that represent extinct species all living species belonging to the family project. Having explained wherein they agree with Dahlan and how they depart from a central proposition about man and from his mode of reasoning about it. Let me try briefly to summarize for you the view of leading scientists today. Julian Huxley. That's Hans ski mare Simpson leaky ranch. I usually run
conex Paul Oakley who either as paleoanthropologists or as evolutionists in general deal with the problem of man's origin nature and difference in one set of terms or another. They all assert the uniqueness of man as an animal. The uniqueness of man is not a Bush they mean first that man possesses certain characteristics forms of behavior springing from certain powers or abilities in this pot that are not possessed to any degree by non-human animals and hence they assert second that man really different in kind from non-human animals not just in degree. You have been listening to the continuity of nature. The first of five lectures about the difference of man and the difference it makes. Our guest speaker for the 1966 Britannica lecture series given at the University of Chicago is Mortimer J Adler the director of the Institute for philosophical research. Next week Mr Adler will talk about a man and a brute. The
difference of man and the difference it makes is produced for a national educational radio by the University of Chicago. This is the national educational radio network.
Mortimer Adler lectures
The continuity of nature, part 2
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University of Chicago
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This program presents the second part of Mortimer Adler's lecture, "The Continuity of Nature."
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Series of five lectures by Dr. Mortimer J. Adler, Director of the Institute for Philosophic Research in Chicago. Title of lecture series: "The Difference of Man and the Difference It Makes."
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Producing Organization: University of Chicago
Speaker: Julin, Joseph R.
Writer: Adler, Mortimer Jerome, 1902-2001.
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University of Maryland
Identifier: 66-33-1 (National Association of Educational Broadcasters)
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Duration: 00:29:32
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