Posted on 01/23/2006 4:31:58 PM PST by PatrickHenry
Scientists at the Georgia Institute of Technology have found genetic evidence that seems to support a controversial hypothesis that humans and chimpanzees may be more closely related to each other than chimps are to the other two species of great apes – gorillas and orangutans. They also found that humans evolved at a slower rate than apes.
Appearing in the January 23, 2006 issue of the Proceedings of the National Academy of Sciences, biologist Soojin Yi reports that the rate of human and chimp molecular evolution – changes that occur over time at the genetic level – is much slower than that of gorillas and orangutans, with the evolution of humans being the slowest of all.
As species branch off along evolutionary lines, important genetic traits, like the rate of molecular evolution also begin to diverge. They found that the speed of this molecular clock in humans and chimps is so similar, it suggests that certain human-specific traits, like generation time, began to evolve one million years ago - very recently in terms of evolution. The amount of time between parents and offspring is longer in humans than apes. Since a long generation time is closely correlated with the evolution of a big brain, it also suggests that developmental changes specific to humans may also have evolved very recently.
In a large-scale genetic analysis of approximately 63 million base pairs of DNA, the scientists studied the rate at which the base pairs that define the differences between species were incorrectly paired due to errors in the genetic encoding process, an occurrence known as substitution.
"For the first time, we've shown that the difference in the rate of molecular evolution between humans and chimpanzees is very small, but significant, suggesting that the evolution of human-specific life history traits is very recent," said Yi.
Most biologists believe that humans and chimpanzees had a common ancestor before the evolutionary lines diverged about 5-7 million years ago. According to the analysis, one million years ago the molecular clock in the line that became modern humans began to slow down. Today, the human molecular clock is only 3 percent slower than the molecular clock of the chimp, while it has slowed down 11 percent from the gorilla's molecular clock.
This slow down in the molecular clock correlates with a longer generation time because substitutions need to be passed to the next generation in order to have any lasting effect on the species,
"A long generation time is an important trait that separates humans from their evolutionary relatives," said Navin Elango, graduate student in the School of Biology and first author of the research paper. "We used to think that apes shared one generation time, but that's not true. There's a lot more variation. In our study, we found that the chimpanzee's generation time is a lot closer to that of humans than it is to other apes."
The results also confirm that there is very little difference in the alignable regions of the human and chimp genomes. Taken together, the study's findings suggest that humans and chimps are more closely related to each other than the chimps are to the other great apes.
"I think we can say that this study provides further support for the hypothesis that humans and chimpanzees should be in one genus, rather than two different genus' because we not only share extremely similar genomes, we share similar generation time," said Yi.
Even though the 63 million base pairs they studied is a large sample, it's still a small part of the genome, Yi said. "If we look at the whole genome, maybe it's a different story, but there is evidence in the fossil record that this change in generation time occurred very recently, so the genetic evidence and the fossil data seem to fit together quite well so far."
whosoever shall say, Thou fool, shall be in danger of hell fire.
That's the load of crap I disagree with. Especially when the liberals start claiming we are most closely related to bonobos as they are doing if you read some of the other posts. And as I point out, it is politically driven. Bononbos are promiscuous, which is why the liberals love them and want to prove we are descended from them. The academic versions of Mary Mapes and Dan Rather are out there lying their respective PHD asses off in order to prove it.
I'm not admitting, I'm claiming, but I'm not claiming like the liberals that we are related to a particular one. Hence my peaches & apples analogy.
Ahhh... No True Scotsman
No, it's more like saying you're more closely related to your first cousin Jack than you are to your first cousin Jill when the relationship between you and either of them is the same. I'm quite sure if you did a DNA study between you and all of your first cousins, one of them would come up "closer" Would you then claim that your aunt and uncle are really your parents? Well that's what the liberals are doing with this chimpanzee / bonobos nonsense
It's got nothing to do with sex, or your delusional conspiracy of scientists.
You are simply choosing to ignore dNA evidence for the easy "if the glove don't fit you must acquit" (Hey there was a conspiracy against OJ too, maybe you're on something)
"on" = "onto"
And you know this because........
Your ignorance of what evolution is is as vast as the universe itself. Evolution does not concern jupiter. Evolution does not concern crystals. As for the ring around your finger - if a proto-human with mutation of "a ring on their finger" existed and "the ring" gave that creature a reproductive advantage over all of the other individuals within it's species, there is a good chance that you WOULD have a ring on your finger. However, the universe went with "eyes & brain (in some cases)" over the "ring on finger" for usefulness.
Oop oop eep eep ook ook ook ook!
The first is the fish Eusthenopteron the other is the early amphibian Icthyostega.
Are they saying that gorillas and orangutans are more highly evolved than humans are?
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Just a thought, but here in Baltimore, we've had 27 murders in the first few weeks of this year. That's in a land area of approx. 80 square miles.
It would be interesting to know how many murders have happened in a densely populated 80 square miles of a given habitat of gorillas and/or orangutans.
hi wcb. That analogy is very compelling on the surface. However, the comparison ends at the molecular level. At that level, there are natural processes that produce ordered, self assembled systems. They follow their own chemical paths. No need for a guiding hand. A watch, or a computer, are not the result of molecular self assembly.
“there are natural processes that produce ordered, self assembled systems. They follow their own chemical paths. No need for a guiding hand”
Could you please elaborate? What natural process produces ordered self assembled systems?
My brain is more developed than my child's brain. I don't look or act like a child (usually). My child cannot type, read, speak, or reason.
According to your logic, apparently my child and I are not related.
Peter Tork of the Monkees is playing with his new band, Shoe Suede Blues, at the Rams Head Tavern tonight in Annapolis MD.
I'm gonna pass.
If only Rod Steward had stopped evolving after recording Every Picture tells a Story and A nod is as good as a wink to a blind horse, then we would not be subjected to listening to him attempt to croon standards.
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