silber@voodoo.ucsb.edu (08/01/89)
-Message-Text-Follows- part of chris malcolm's rejection of ramesh sitaraman's observation (re: the differential rates of evolution of different subsystems) was: >>Note that the largest and most rapid recent evolutionary change which >>the human race has suffered is a very considerable change in brian size; >>this is usually presumed to be correlated with becoming cleverer. If we What do you mean by 'rapid', what do you mean by 'human species'? even the proto-humans of three-million years ago didn't have pea-brains. The evolution of 'the brain' (the evolution of intelligence) is really a trans-species phenomenon several hundred millions years in duration. Brain size, as i recall, is not that strongly correlated with intelligence; it is rather the specialization of certain subsystems etc. Intelligence did not emerge in one rapid burst of evolutionary ingenuity, but rather very slowly as vraious 'onion skin layers' were added to the vertebrate control apparatus.
cjoslyn@bingvaxu.cc.binghamton.edu (Cliff Joslyn) (08/02/89)
In article <2153@hub.UUCP> silber@voodoo.ucsb.edu writes: >>>Note that the largest and most rapid recent evolutionary change which >>>the human race has suffered is a very considerable change in brian size; >>>this is usually presumed to be correlated with becoming cleverer. If we > >What do you mean by 'rapid', what do you mean by 'human species'? even the >proto-humans of three-million years ago didn't have pea-brains. Further, there are many other gross morphological differences between humans and non-humans: erect posture, loss of estrus, loss of most body hair, growth of speech mechanisms. No doubt the selective pressures on all of the above interacted with brain development in our ancestors in a complex, circular way. Unless someone can provide a decent objective measure of "size of evolutionary change" it would seem like simple prejudice to say that brain increase is the most "significant" of all of these. -- O----------------------------------------------------------------------> | Cliff Joslyn, Cybernetician at Large | Systems Science, SUNY Binghamton, cjoslyn@bingvaxu.cc.binghamton.edu V All the world is biscuit shaped. . .
cam@edai.ed.ac.uk (Chris Malcolm cam@uk.ac.ed.edai 031 667 1011 x2550) (08/04/89)
In article <2355@bingvaxu.cc.binghamton.edu> cjoslyn@bingvaxu.cc.binghamton.edu.cc.binghamton.edu (Cliff Joslyn) writes: >In article <2153@hub.UUCP> silber@voodoo.ucsb.edu writes: [I wrote >>>>] >>>>Note that the largest and most rapid recent evolutionary change which >>>>the human race has suffered is a very considerable change in brian size; >>>>this is usually presumed to be correlated with becoming cleverer. If we >> >>What do you mean by 'rapid', what do you mean by 'human species'? even the >>proto-humans of three-million years ago didn't have pea-brains. > >Further, there are many other gross morphological differences between >humans and non-humans: erect posture, loss of estrus, loss of most body >hair, growth of speech mechanisms. No doubt the selective pressures on >all of the above interacted with brain development in our ancestors in a >complex, circular way. Unless someone can provide a decent objective >measure of "size of evolutionary change" it would seem like simple >prejudice to say that brain increase is the most "significant" of all of >these. The discussion started with assertions that the special human characteristic was our mentality - abstract thought etc. - and that human mental capacity had evolved so slowly and so long ago that it must therefore be virtually identical - in genetic endowment - among races, sexes, and individuals. Three million year old proto-humans didn't have pea brains, but they did have brains noticeably smaller than ours - a vague memory suggests about half-way between us and chimps. I think that Cro-Magnon and Neanderthal man were the first to reach the range of modern brain size, and that that corresponded in time with a steep acceleration in the rate of improvement of artefacts and art. Upright posture was developed in proto-humans before modern brain size. As far as I know it is not known when we lost hair or estrus, but my hunch - call it prejudice if you will - is that these are less connected with mental powers than brain size :-) Speech, semantics, and brain-power, are, I agree, a chicken and egg problem. Cliff's point about an objective measure of amount of evolutionary change is good, but I don't see how we can get it short of decoding the chromosomes. The much-quoted 1% difference between humans and chimpanzees is meaningless without knowing how the code works. For example, I could take a sponge cake recipe and make a 1% change - in the recipe - by saying "use a hundred times as much butter and sheep's brains instead of eggs". Note that even if our brains had fully evolved 100 million years ago, that doesn't mean the genetic endowment of brainpower would have evened out between individuals; it could be advantageous to have a mix of mental talents, just as it is advantageous to have a mix of blood types, or mixes of castes in termite colonies. In summary, by "rapid", "recent", and "significant" what I meant was that in the fossil record from proto-ape to human the last major change of dimension was cranium size, and that this happened sufficiently much faster than the previous development of cranium size in mammals and primates in general, that words like "sudden", "startling", "explosive" are sometimes used to describe it. For some special reason, at that time, having a small brain was frequently fatal, or at least unattractive to the opposite sex (the peacock-tail theory of brain-power). -- Chris Malcolm cam@uk.ac.ed.edai 031 667 1011 x2550 Department of Artificial Intelligence, Edinburgh University 5 Forrest Hill, Edinburgh, EH1 2QL, UK
b27y@vax5.CIT.CORNELL.EDU (08/05/89)
This arguement brings up an interesting problem that I have with evolution: Isn't it just a little far fetched to think that genetic "advancements" like intellegence happened using only the mechinisms of random selection of genes and survival of the fittest. Before anyone worries: I am not arguing for a higher power (God etc.) I just think that those two mechinisms don't seem to be enough.. I realize that the evidence doesn't stack up much in my favor. questions: What about "reverse" evolution? Some researchers (I do not remember all the details) I recall seem to have found evidence of speices which evolved attributes which made survival HARDER. More specifically: A type of pike, whose teeth where evovling so that they stick outwards, which made cating and eating prey MORE difficult? This deosn't seem possible under the orignal Dawrininan discriptions. This of course implies to me that there may be something more to evolution, some other factors influencing how we reproduce. The only preminition that I have had is that the mechinism of mutation may not be as random as it seems. Is there any evidence which supports this? or am I just opening myself up to net.flame as heretic of the month. I am also interested in results of Genetic algorithms which may contadict me. --misha-- /*----------------------------------------------------------------------*/ /* Michael Gray b27y@vax5.cit.cornell.edu (ARPA) */ /* Misha Computing b27y@crnlvax5 (BITNET) */ /* 526 Stewart Ave UUNET!CORNELL!VAX5!b27y (UUNET) */ /* Ithaca N.Y. 14850 (607)277 2774 */ /* */ /* "Save the Humans" --Bumper Sticker */ /*----------------------------------------------------------------------*/
lee@uhccux.uhcc.hawaii.edu (Greg Lee) (08/06/89)
From article <19229@vax5.CIT.CORNELL.EDU>, by b27y@vax5.CIT.CORNELL.EDU: " ... " questions: " What about "reverse" evolution? Some researchers (I do not remember " all the details) I recall seem to have found evidence of speices which " evolved attributes which made survival HARDER. More specifically: A type of " pike, whose teeth where evovling so that they stick outwards, which made " cating and eating prey MORE difficult? This deosn't seem possible under the " orignal Dawrininan discriptions. ... In _The Meaning of Evolution_, Simpson proposes an explanation of how such things can happen. He gives an example of a type of elk whose antlers came to be burdonsomely large, and claims this happened because of a genetic link between antler size and overall body size. Increased body size was sufficiently advantageous to overcome the disadvantage of the outsized antlers. Whether such an argument could be made for your pike, that I don't know. Greg, lee@uhccux.uhcc.hawaii.edu
demers@beowulf.ucsd.edu (David E Demers) (08/06/89)
In article <19229@vax5.CIT.CORNELL.EDU> b27y@vax5.cit.cornell.edu (Michael Gray) writes: > Isn't it just a little far fetched to think that genetic >"advancements" like intellegence happened using only the mechinisms of >random selection of genes and survival of the fittest. No. While the odds of ONE useful adaptation occurring in any particular reproductive event may be small, there are literally billions of these events. Once anything develops through genetic recombination which provides enhanced fitness, that individual is more likely to reproduce and pass the characteristic(s) on. It doesn't take many generations for the trait to sweep through the population, even if it only provides a very slight survival/fitness edge to the holder. Think of an analogy with compound interest... >Before anyone worries: I am not arguing for a higher power (God etc.) >I just think that those two mechinisms don't seem to be enough.. I realize >that the evidence doesn't stack up much in my favor. Well, it's mostly trying to understand the statistics. I don't think humans generally are able to grasp the effect of many "experiments" over a long period of time. Remember, it has taken a LONG time to get to where we are today. >questions: > What about "reverse" evolution? Some researchers (I do not remember >all the details) I recall seem to have found evidence of speices which >evolved attributes which made survival HARDER. More specifically: A type of >pike, whose teeth where evovling so that they stick outwards, which made >cating and eating prey MORE difficult? This deosn't seem possible under the >orignal Dawrininan discriptions. I suspect that there is some explanation based on increasing fitness. Survival is not the only thing involved. Species need to optimize reproductive ability. For example, pheasants' tails do not seem to assist in survival, but DO assist in attracting a mate. But I don't know anything about the fish you mention... > This of course implies to me that there may be something more to >evolution, some other factors influencing how we reproduce. The only >preminition that I have had is that the mechinism of mutation may not be as >random as it seems. Evidence seems to be that most mutations are harmful, and that mutation rates are fairly low. I don't think that there is much evidence for non-random mutations. Anyone know? >Is there any evidence which supports this? or am I just opening myself up >to net.flame as heretic of the month. I am also interested in results of >Genetic algorithms which may contadict me. >--misha-- While dabbling in Genetic Algorithms, I have been impressed by the robustness. I've used GA to search very large discrete space and almost always can find a global optimum. There is a good book by David (oops, last name is Goldman or Goldberg...) on genetic algorithms, including lots of code fragments. As to evolution in general, you might read "The Blind Watchmaker" by Richard Dawkins. It strongly advocates his ideas and shows how the seemingly improbable "random combinations & mutations" are not so unlikely after all. The key idea is that most benefits come from combining already existing "subsystems", rather than from mutations. Dave DeMers demers@cs.ucsd.edu
andrew@berlioz (Lord Snooty @ The Giant Poisoned Electric Head ) (08/06/89)
It's been pointed out that size of brain does not "correlate well" with intelligence. It's also trivially obvious that if you offered me two neural networks for intelligence emulation, I would choose the one with richer connectivity (assuming I'd know what to do with it). This raises therefore the issue of accelerating brain "potential". Perhaps in some distant(?) time, we'll have evolved techniques for either surgical brain enhancements, or a more direct man/machine interface. After all, technology is based on the synergy of collective effort on a shared and accumulated knowledge base, albeit at a much coarser-grained level than that which I had in mind. Science fiction? Maybe. If we can develop these techniques, however, the "inheritance of intelligence" issue will become a dodo. In one particular political scenario, you are intelligent in direct proportion to your personal wealth - how much of the stuff you can afford! -- ........................................................................... Andrew Palfreyman There's a good time coming, be it ever so far away, andrew@berlioz.nsc.com That's what I says to myself, says I, time sucks jolly good luck, hooray!
jps@cat.cmu.edu (James Salsman) (08/07/89)
In article <591@berlioz.nsc.com> andrew@berlioz (Lord Snooty @ The Giant Poisoned Electric Head ) writes: > It's been pointed out that size of brain does not "correlate well" with > intelligence. It's also trivially obvious that if you offered me two > neural networks for intelligence emulation, I would choose the one with > richer connectivity (assuming I'd know what to do with it). That's easy to say, but I'll bet that you can't define what you mean by "richer." The neural-net structure of the best F-14 fighter pilot is probably quite different from the structure of a progammer's neural-net. Exercise: what is the optimal structure of an AI researcher's neural-net. Also, by "size of brain" do you mean (A) Weight (B) Volume (C) Number of Neurons (D) Number of Connections (E) Resolution of each Connection (F) Rate of Connection Change (G) Number of desernable Neurotransmitters or some combination of these, or somthing else? :James Disclaimer: The University doesn't influence my opinions, and I don't influence the University's...most of the time. -- :James P. Salsman (jps@CAT.CMU.EDU)
kim@watsup.waterloo.edu (T. Kim Nguyen) (08/08/89)
In article <5768@pt.cs.cmu.edu> jps@cat.cmu.edu (James Salsman) writes:
Also, by "size of brain" do you mean
(A) Weight
(B) Volume
(C) Number of Neurons
(D) Number of Connections
(E) Resolution of each Connection
(F) Rate of Connection Change
(G) Number of desernable Neurotransmitters
or some combination of these, or somthing else?
I think the accepted meaning of "size of brain" is (b) its volume.
Cro-Magnon was the race whose cranial volume approached that of modern
man (in fact, it exceeded ours). Coincidentally :-) Cro-Magnon was
also the first race to innovate, use language, and develop art. Read
Jared Diamond's article in Discover, earlier this year (March?).
--
Kim Nguyen kim@watsup.waterloo.edu
Systems Design Engineering -- University of Waterloo, Ontario, Canadab27y@vax5.CIT.CORNELL.EDU (08/08/89)
In article <5768@pt.cs.cmu.edu> jps@cat.cmu.edu (James Salsman) writes: >..... Exercise: what is the optimal structure of an >AI researcher's neural-net. > >Also, by "size of brain" do you mean > (A) Weight > (B) Volume > (C) Number of Neurons > (D) Number of Connections > (E) Resolution of each Connection > (F) Rate of Connection Change > (G) Number of desernable Neurotransmitters >or some combination of these, or somthing else? > >:James > While i have only dabled in Neural-nets. i am nor sure if there is any real measure yet for neural-nets for this: specialization of functional units: Minksy loves to talk about these thing (_Society of Mind_), and modern brain physiology seems to indicate that intellegent systems have several functional compenents - each with its own tasks, yet all very highyl connected to together. I seem to recall that it is the reason that we are supposed to be smarter than whales(?), yet have smaller brains (I admit that the last sentence is a subjective statement, and maybe wrong). I am sure that some NN guys might like to think that each "neuron" is a functional unit, but I feel the neccesity to restrict my self to abstract functions like :speech, vision, etc.. /*----------------------------------------------------------------------*/ /* Michael Gray b27y@vax5.cit.cornell.edu (ARPA) */ /* Misha Computing b27y@crnlvax5 (BITNET) */ /* 526 Stewart Ave UUNET!CORNELL!VAX5!b27y (UUNET) */ /* Ithaca N.Y. 14850 (607)277 2774 */ /* */ /* "Save the Humans" --Bumper Sticker */ /*----------------------------------------------------------------------*/
andrew@berlioz (Lord Snooty @ The Giant Poisoned Electric Head ) (08/08/89)
In article <5768@pt.cs.cmu.edu>, jps@cat.cmu.edu (James Salsman) writes: > Also, by "size of brain" do you mean > (A) Weight > (B) Volume > (C) Number of Neurons > (D) Number of Connections > (E) Resolution of each Connection > (F) Rate of Connection Change > (G) Number of desernable Neurotransmitters > or some combination of these, or somthing else? Some combination of these. -- ........................................................................... Andrew Palfreyman There's a good time coming, be it ever so far away, andrew@berlioz.nsc.com That's what I says to myself, says I, time sucks jolly good luck, hooray!