Evidence for evolution, Installment 2: Cytochrome c

by seattleniceguy 53 Replies latest jw friends

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  hooberus

  On the other hand, if species are related in an evolutionary sense, then we should expect to find cytochrome c protein sequences are more similar for related species, and less similar as relatedness decreases.

  I agree that this is probably expected.
  

  Since other evidence leads us to believe that chimps and humans (for example) are closely related, then we will go way out on a limb and predict that human and chimp cytochrome c should be very similar, whereas yeast cytochrome c should be very different from both humans and chimps.

  Both evolutionists and creationists expect that creatures which are similar to each other phenotypically/bodily (Ie: humans and chimps) will also have more closely sharred bio-chemical similarities than with creatures which are less similar (ie: humans and yeast).

  Those are the predictions. What are the observations?

  Human and chimpanzees have identical cytochrome c sequences. Further, human and chimpanzee cytochrome c differs by about 10 amino acids from all other mammals. All mammals, in turn, have similar cytochrome c (within about 10%) to any other mammal, but a greater degree of difference with any non-mammal. As it turns out, for any species, its cytochrome c sequence is extremely similar to other species that are phylogenically related to it. As the distance between two species increases, the sequences become vastly different. Human cytochrome c and yeast cytochrome c are, as mentioned, about 40% different.

  I hope to shortly post some information on the pattern.
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  hooberus

  Before moving on I wanted to make a point about a calculation in one of my previous posts (I have not been able to edit the post). Regarding my statement:
  

  The number of different possible functional versions of cyctochrome c sequences calculted by Yockey is staggering (2.3 x 10 93 ). However, Yockeys calculations also show that when compared to the number of of possible sequences of the same length as cyctochrome c (110 amino acid length 2.0 x 10 137 possible sequences) that functional cyctochrome c sequences are exceedingly rare.

  2.3 x 10 93 1.15 x 10 137 = 2.0 x 10 -44

  The above calculation was posted by me, not to state that the odds against the evolutionary generation of cyctochrome c are 2.0 x 10 -44 , but that out of the possible sequences (of the same length) functional cyctochrome c sequences are exceedingly rare. This could be a problem for evolution if it is calculated that in order to obtain even one of these (or a similar gene) unrealistic assumptions have to be invoked.

  Furthermore, even if such a gene were generated in order for it to become "ubiquitous" it would have to become fixated into the entire population of replicating organisms. Popuation genetics calculations could possibly pose a severe problem for this.

  source for some points: http://www.answersingenesis.org/home/area/magazines/tj/docs/TJv15n3_Protein_Families.pdf
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  hooberus

  http://www.talkorigins.org/faqs/comdesc/section4.html#protein_redundancy

  In terms of a scientific statistical analysis, the "null hypothesis" is that the identity of non-essential amino acids in the cytochrome c proteins from human and chimpanzee should be random with respect to one another. However, from the theory of common descent and our standard phylogenetic tree we know that humans and chimpanzees are quite closely related. We therefore predict, in spite of the odds, that human and chimpanzee cytochrome c sequences should be much more similar than, say, human and yeast cytochrome c - simply due to inheritance.

  Humans and chimpanzees have the exact same cytochrome c protein sequence. The "null hypothesis" given above is false. In the absence of common descent, the chance of this occurrence is conservatively less than 10 -93 (1 out of 10 93 ). Thus, the high degree of similarity in these proteins is a spectacular corroboration of the theory of common descent. Furthermore, human and chimpanzee cytochrome c proteins differ by ~10 amino acids from all other mammals. The chance of this occurring in the absence of a hereditary mechanism is less than 10 -29 . The yeast Candida krusei is one of the most distantly related eukaryotic organisms from humans. Candida has 51 amino acid differences from the human sequence. A conservative estimate of this probability is less than 10 -25 .

  The talk origins arcticle uses negative evidence (mathematical calculations) against one naturalistic hypothesis (random cyctochrome c sequences) as evidence for another naturalistic hypothesis (commom descent). The problem with this is that the issue under debate is not one naturalistic scenario vs. another (less likely one ), but instead creation vs. evolution. Even before cytochrome c sequence data was calculated it was already knwn that life exists in a nested hierarchy with humans and chimpanzees being relatively close to each other. Creationists already believed that God had created life according to a pattern and I believe fully expected a pattern of genotypic similarities corresponding to phenotypes. In fact regarding the pattern the non creationist molecular biologist Michael Denton wrote:

  "One of the most remarkable features of these new biochemical discoveries is undoubtedly the way in which the pattern of molecular diversity seem to correspond to the predictions of typology." Evolution: A Theory in Crisis page 290.*

  Since creation according to typology is an option that also predicted the pattern of similarities, the negative evidence against random sequence odds is not necessarily positive evidence for common descent.

  *In fact is a whole chapter in the book Evolution a Theory in Crisis specifically discusses the pattern of cyctohrome c and how the pattern is much better explained by typology rather than common descent.
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  AlmostAtheist

  Michael Denton wrote:

  "One of the most remarkable features of these new biochemical discoveries is undoubtedly the way in which the pattern of molecular diversity seem to correspond to the predictions of typology." Evolution: A Theory in Crisis page 290.*

  A response to Denton's work can be viewed here: http://www.infidels.org/library/modern/mark_vuletic/denton.html

  It's a bit over my head, but maybe you guys that are into this sort of thing can sort it out. It seems that to become a serious evolutionist (as opposed to some grunt that just believes evolution) you have to understand words like "non-saltation" and "interconvert", so I guess I'm not in the club. If I only cared enough to dig into it, I'd happily translate this mess into something a non-evolutionist could understand. That's where the creationists have us hands down; they care, we don't. Believe it, don't believe it, whatever.

  SNG, you seem to be the only hope of the non-evolutionist ever understanding the evolutionist's views.

  "Help us, Obi-Wan SNG, you're our only hope."

  Dave

  Dave
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  Terry

  I'm really too tired right now to do this question justice; but, in a nutshell.....

  The physical differences in humans can be accounted for by evolution. But, how do you account for the vast intellectual gap? It is light years across.

  Apes with hand signals aren't convincing proof of mere differences in quality of intellect.

  James Joyce and "water+fruit" aren't commensurable.

  Something extraordinarily special visits the human brain which is entirely beyond the capacity of any creature non-human.

  Rachmaninoff's piano concertos aren't Ko Ko the chimp's pastime.

  Logrithms and Relativity are beyond Cheetah or the Great Apes.

  You get the idea.

  Why oh why is the mind of man (i.e. man and woman) so immeasurably transcendant to that of his nearest bestial realtives? How do we account for it?

  Does Evolution give us a clue?

  Terry
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  Narkissos

  Terry,

  My 2 cents: human language, although initially developed as a practical device, creates and populates a symbolical realm of its own. Once a homo loquens appears s/he is caught in this game and cannot live by bread alone anymore. Actually wherever there is "bread" there is "culture" -- art, music, stories, fiction, imagination.
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  Terry

  My 2 cents: human language, although initially developed as a practical device, creates and populates a symbolical realm of its own

  No mean feat!

  We seem to be the only species with Hamlet's Soliloquy. The effect of language is inestimable; but, I'm seeking the cause behind this effect. Where in evolution is there an explanation for the development of language (and susequent intellectual profundity) in humans only?

  Humans here.........................................................................................other animals here.

  T.
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  Midget-Sasquatch

  Terry,

  I'm by no means an evolutionary expert, but here's a thought...for whatever its worth.

  Many animals can alter characteristics of their species by the mates they choose (e.g. longer horns, longer feathers, more impressive dance or song). Evolutionary forces can be exerted within the species itself. Maybe sexual selection had a large part in the emergence of our species' creative faculties.

  Someone who was more artistic, musical, or inventive as well as more astute would make for a more interesting mate. That could serve as a driving selective force beyond the basic survival demands of te environment.

  An appealing mate for alot of people isn't strictly focussed on the physical.....Thankfully.
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  Terry

  Many animals can alter characteristics of their species by the mates they choose (e.g. longer horns, longer feathers, more impressive dance or song). Evolutionary forces can be exerted within the species itself. Maybe sexual selection had a large part in the emergence of our species' creative faculties.

  Someone who was more artistic, musical, or inventive as well as more astute would make for a more interesting mate. That could serve as a driving selective force beyond the basic survival demands of te environment.

  So, are you postulating the actual existence of animals who are artistic, musical, inventive and more astute as a difference in DEGREE which improves over time due to sex selection?

  I'm wary of the circularity. But, I might be missing a subtle point.

  T.
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  Satanus

  Terry

  The direction that you ar taking it isn't the point at all. I'm surprised that you failed to get the point. That principle has been the basis of evolution for millenia.

  S