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Author | Topic: ID/Creationism - Comparison of Human and Chimp Genomes | |||||||||||||||||||||||
Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
Don't get me wrong, it was allways there but the old saw that the DNA is 99% the same has been proven to be false. It isn't an old saw, it is an old estimate based on a crude technique and one acknowledged to be crude. As better techniques have come along better estimates have followed. There are still a number of different possible metrics to measure such conservation by however, and not all of them will give you 95% as your figure.
Unless scientists have a genetic mechanism for tripling the size of an ape brain then this is all supposition and speculation about what might be an alternative to special creation. You yourself have referenced research on another thread about the ASPM gene. If mutations in a gene can cause a 70% reduction in the size of a brain why do you think that mutations acting over several genes could not increase the size of the brain? TTFN, WK Edited by Wounded King, : typographical errors
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Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
Funny thing is the research I am reading is saying that the evolution of human brain genes is a special event. You do realise that a news article or press release isn't actually 'research' per se I hope. In particular the quotes you provide such as 'nothing short of spectacular' don't actually seem to come from the research paper at all. Being a special event is not the same as being an impossible event, which is what you seem to be claiming.
Let's just put it in perspective 83% of the protein coding genes show changes at an amino acid sequence level and I do mean 83% of all the protein coding genes in the human genome. There are at least 40,000 amino acids that diverge between chimps and humans, many in brian development genes. 40,000 amino acid substitutions? That doesn't really sound like a lot. How many of those substitutions are functionally synonymous? As you yourself pointed out on the other thread such a difference could be accounted for by as little as 40,000 single nucleotide substitutions, that isn't a lot of genetic difference. If you wanted to make the point that a small amount of genetic difference can contribute to a large amount of functional difference then you seem to be making a case in favour of evolution.
This is the clicher, you don't have 25 mya to play with or even 2.5 mya. You have the space of time from Homo habilis and Turkana Boy, that's measured in the hundreds of thousands, not millions of years. This isn't actually the case. The problem is that you think it is all about size. you are hung up on cranial capacity but cranial capacity isn't the be all and end all of the differences between human and chimp brains. So you don't require all of those thousands of mutations across thousands of genes just to make a brain 3 times bigger than a chimp's, you need them to make a human brain instead of a chimp's. So basing the interval all these mutations must occur in on the cranial capacity of Homo habilis and Turkana boy is massively fallacious. TTFN, WK Edited by Wounded King, : Correction of typographical errors
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Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
It makes sense that certain genes are going to be different but not in genes involved in the brain or liver. Why ever not? Are all vertebrates brains identical? All mammalian brains? Plainly not, so why on earth would you not expect to see diferences?
Sure, 40,000 amino acids don't seem like a whole lot until you take into consideration that this is 120,000 nucleotides at the very least. Could you run through your math here for me? As I pointed out in the post you were replying to 40,000 amino acid changes can be accounted for by 40,000 nucleotide substitutions. In fact if you allow single nucleotide deletions or insertions and a subsequent frame shift you could have several amino acids changed by a single nucleotide mutation. I can't concievably see where you get that you require 120,000 mutations, or rather I think I can 40,000 X the 3 nucleotides in a codon, unfortunately this calculation makes absolutely no sense whatsoever.
Not only do they have to be substituted in triplet codons Completely wrong, what on earth gave you such an arseabout idea?
Most of the time when an indel (mutation of length) happens a stop codon is inserted, it's just as well, it would fold into a usefull protein anyway. Most of the time, but not all of the time.
Brain tissue is some of the most biologically expensive pieces of real estate in the human genome to have adaptive mutations. Which may be exactly why we still see such a high degree of conservation in the neural genes of many organisms and huam's appear to have had an 'accelerated evolution'. As has previously been suggested to you such high, maintenance high complexity brains are not neccessarily a fitness advantage, that they appear to have been so for man and his immediate ancestors may be why they have such an unusal pattern of evolution.
Then there is this regulatory gene in the ...... hundreds of thousands. Just restating the same crap argument doesn't make it suddenly better. We were already discussing Har1 on another thread and I'd be glad to continue discussing it there. Once again you can'tdetermine an interval for the evolution of all the differences between the chimp and human neural genes, or even those ones which appear subject to positive selection, based solely on cranial capacity because cranial capacity is by no means the sole difference between chimp and human brains. If you didn't understand the argument I can explain it further, but just restating your original claim is no sort of rebuttal. All your evidence suggests is that mutations which increased the cranial capacity 3 fold occurred in this time period. How many mutations in how many genes that would require is a matter for speculation, but it certainly isn't all of the neural genes distinct in human and chimp. Don't take my word for genes involved with neural functions, look up mutations affecting neural functions in the human brain. There is nothing indicating beneficial affects and yet it is here that the burden of proof weighs heaviest upon the evolutionist. This is such a crap argument and creationist/IDers use it all the time. Of course the literature on neural developmental defects is extensive as opposed to the literture on 'beneficial' neural mutations because people aren't brought into hospitals because they work well but because there is some problem. Therefore there is a wealth of medical research focused on what is wrong with peoples' development. Even to detec a 'beneficial' neural mutation would require a massive effort of genetic screenin and lineage tracing. Making such an arguemnt just suggests you haven't the faintest idea either of how the literature has got to be the way it is or of what would be required to demonstrate a beneficial neural mutation in humans. Its like all the people complaining that all the drosophila mutagenesis screens produced was embryonic lethals, completely ignoring the fact that the screens are frequently actually designed to identify embryonic lethals. TTFN, WK
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Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
Welcome to the boards.
And its just a .5% gene distance that determines all of the different fruits Could you explain what you mean here? Are you saying that all different varieties of banana are only seperated by 0.5% divergence or that all fruiting plants are? In either case some sort of reference to back this up would probably be a good idea.
I personally don't believe in evolution, but in i.d. because there can only be new species of an animal not a new type of animal. This doesn't sound like ID, it sounds like good old fashioned creationism of the created kinds kind.
Also dolphins r completely hairless and have and oily skin to protect them. A land mammal trying to slowly evolve this would die before it could fully adapt. Evidence?
How could this be true if reptiles do not have the DNA to make feathers. Because the idea is that the birds evolved from reptiles and in so doing gained the specific DNA prodcing feathers, there are a number of feathered dinosaur fossils which suggst that rudimentary feathering was already present in the theropods before many more avian characteristics developed (Xing et al, 1999).
And is the fact that reptiles are still around today contradict this theory. No it doesn't contradict the theory, there is no suggestion that all reptiles evolved into birds, after all some of them evolved into mammals. Modern mammals, modern birds and modern reptiles are all thought to have ancient reptilian ancestors and at some point far enough back a common reptilian ancestor.
this is my first post and i have a lot to learn! Indeed you do, but being able to recognise that fact is a good first step in remedying the situation. TTFN, WK
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Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
I was under the impression that the difference between scales and feathers lay in one gene I think this is a slight misrepresentation. Blocking BMP signalling in a chickens leg will lead to some of the scutes on the leg developing as feathers (Zou and Niswander, 1996). This means that feathers and scutes are very closely related but scutes are distinct from reptilian scales. It has also been suggested that feathers are in fact the primitive structure from which scutes have evolved rather than, as had previously been proposed, the other way round. TTFN, WK
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Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
mean it is a well proven fact that dolphins have mucn bigger and HIGHERLY developed brains than humans. Highly developed in what way? The most recent research actually suggests that much of the dolphins large brain is composed of fatty glial cells which act to maintain its brains temperature.
A dolphin is at the peak of animal intelligence. Are you actually basing this on anything scientific?
And if chimps evolved from a common ancestor as humans then how come chimps never became as smart, we both would have had the same amount of time of evolution. This is true but we haven't both been in the same environment over all that time and have therefore been under different selective pressures. If we did have a close relative with an equivalent level of intelligence we'd probably have killed it off, either directly or by competition for the same resources as has been proposed to be the fate of the neanderthals. TTFN, WK
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