hughfarey wrote:Mazzy wrote:It's called backing my view with more than my opinion. It is nice to chat, but I find it a waste of time to go around in circles using vagaries and opinion alone.
Really? then it's good to read some proper research to see whether it really does back your opinion.
Absolutely! However, unlike you, hughfarey, I actually understand what I'm reading.
The Myth of 1%. Well, I think we've already covered that. It's a popular press generalisation based on some research into small pieces of DNA which are sufficiently similar to be directly comparable. It is not possible to make such an arbitrary statement without stating very specifically what 1% actually means. As you so pertinently quote: “There isn’t one single way to express the genetic distance between two complicated living organisms” and you're obviously correct.
Agreed. However the article states you can't credibly offer a comparison. Don't forget the point the article makes!
"Could researchers combine all of what’s known and come up with a precise percentage difference between humans and chimpanzees? “I don’t think there’s any way to calculate a number,” says geneticist Svante Pääbo, a chimp consortium member based at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. “In the end, it’s a political and social and cultural thing about how we see our differences.”
However, I think you then went too far in saying that because this particular generalisation was not a demonstrable fact, that therefore there was no data to suggest that human, chimp and chicken DNA was more or less similar, thus providing evidence for independent creation. You go so far as to reference the Science Magazine article "The Myth of 1%" without apparently noticing that it refers to research into another way of comparing DNA, replacing 1% with "a whopping 6.4%". 'Whopping', seems to me a little over the top. The authors show that by their method, humans are 93.4% similar to chimps, which hardly supports your stated view that human, chimp and chicken DNA is equally different. Furthermore, your reference to the scientific literature at all hardly supports your other contention that it's all guesswork.
You suggested previously, that I have been vaguely abusive to you. Well I tell you what hughfarey, I haven't negated to notice anything in that article at all. I haven't gone too far at all. Perhaps it is you that should read it again and google the terms you don't understand....Let me draw your attention to this below to clarify what the paper is telling us....
"Hahn and co-workers reported that human and chimpanzee gene copy numbers differ by a whopping 6.4%, concluding that “gene duplication and loss may have played a greater role than nucleotide substitution in the evolution of uniquely human phenotypes and certainly a greater role than has been widely appreciated.”
Do you know what the above, in bold, and the paragraph it is in, actually means? It is referring to gene copy numbers ONLY,where a chromosome now has two copies of this section of DNA, rather than one. The authors were not so silly as to say that there is no way a credible comparison can be made and then offer a comparisative percentage as you appear to have erroneously read into the article.
You then refer to another article that examines an even tinier proportion of an animal's DNA, the "male-specific region of the Y chromosome" (not even the whole chromosome, note), and compared that of humans and chimps in various ways. First they found this:
"Given that primate sex chromosomes are hundreds of millions of years old, theories of decelerating decay would predict that the chimpanzee and human MSYs should have changed little since the separation of these two lineages just six million years ago. To test this prediction, we aligned and compared the nucleotide sequences of the chimpanzee and human MSYs. As expected, we found that the degree of similarity between orthologous chimpanzee and human MSY sequences (98.3% nucleotide identity) differs only modestly from that reported when comparing the rest of the chimpanzee and human genomes (98.8%)."
However, then, to their surprise, they found this:
"Surprisingly, however, > 30% of chimpanzee MSY sequence has no homologous, alignable counterpart in the human MSY, and vice versa. In this respect the MSY differs radically from the remainder of the genome, where < 2% of chimpanzee euchromatic sequence lacks an homologous, alignable counterpart in humans, and vice versa."
You do understand, don't you? That when an evolutionary scientist states they are surprised. It actually means their prediction is WRONG? None the less they never let a few facts and failed predictions get in the way of good story telling.
And they conclude this:
"In aggregate, the consequence of gene loss and gain in, respectively, the chimpanzee and human lineages is that the chimpanzee MSY contains only two thirds as many distinct genes or gene families as the human MSY, and only half as many protein-coding transcription units. By contrast, in the remainder of the genome, comparison of chimpanzee draft sequence with human reference sequence suggests that the gene content of the two species differs by < 1%. Indeed, at six million years of separation, the difference in MSY gene content in chimpanzee and human is more comparable to the difference in autosomal gene content in chicken and human, at 310 million years of separation."
Now, re-reading that, can you honestly say that it leads to this conclusion (yours): "There is ample evidence to support the claim that the chimp and human genomes are not similar at all as is suggested in the OP"? If so, then I can only respectfully disagree. So, of course, does John Hawkes, in his article beginning "Holy Crap!" He too is well aware that human and chimp DNA is overwhelmingly similar except in some small, but important and interesting instances.
Respectfully, I can hardly believe you are back on here using this article to try to challenge me. What remains of the genome to suggest a 1% comparison is not much at all. IOW, the article aligns with what I and others here have been saying. The chimp genome is only similar to mankind when you ignore the plethora of differences.
Here are a few more snips from that paper....
A third sequence class in the human MSY euchromatin – the X-transposed sequences – has no counterpart in the chimpanzee MSY.....
The chimpanzee ampliconic regions are particularly massive (44% larger than in human.....)
In fact, the evolution of ampliconic sequences has outpaced that of X-degenerate sequences, and to such a degree that the ampliconic architecture of the common ancestor’s MSY may be difficult to reconstruct even after an outgroup MSY has been sequenced.
Do you know what an outgroup is and why an out group is needed, and on what basis an out group is chosen as in the comment above?
Now here is a bit of guesswork from that same paper...
Despite the chimpanzee MSY’s elaborate structure, its gene repertoire is considerably smaller and simpler than that of the human MSY (Table 1) as a result of gene loss in the chimpanzee lineage and gene acquisition in the human lineage. For example, we previously discovered that the chimpanzee X-degenerate regions had lost four of 16 genes through inactivating mutations, while the human X-degenerate regions had not lost any genes since the time of the last common ancestor.
So here above we have scientists clearly stating a loss of 4 of 16 genes (25%). Now for the story telling.... The human x-degenerate regions have not lost any since the last common ancestor. Do you suppose that these scientists have healthy DNA from the human/chimp common ancestor so they can make such a claim? They don't even know what that was. Do you know where an outgroup may come in here?
So I maintain the OP hits the nail on the head. NO, we are not 99% the same as chimps and neither is our dna.