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."
Yes I know that, but neither has anything to do with the main message of the post. Your statement was a reference to individuals not adapting to dramatic and quick onset problems. That is what I addressed.
See PH's post 338. He got to the information before I did. Also, I've done this sort of thing for a living so anyone who says things don't self assemble on the chemical level, all I can say is you don't know what you are talking about. PH's links are a good layman's summary without having to get into Gibbs free energy, and the enthalpy and entropy of formation. Just as an aside, when you use soap, the bubbles are a form of self assembly that mimics cell memberane structure. Lipid bilayers form spontaneously in water and they make handy containers for all kinds of chemicals and reactions - just like cells.
We are just as closely related to chimps as to bonobos. But why let facts get in the way of a good moronic rant, eh?
". . are more highly evolved than humans are?"
Scientifically speaking, there is no such thing as "more highly evolved."
You are either more "fit" for your environment or you are not. That is, you are more likely to live and have babies, or not.
For example, a cockroach is more "fit" than a human to live underneath a refrigerator and eat food the cat stuck under there --- that is, more likely to live and have babies.
Here, gorillas and orangutans can live, exposed, out in the jungle better than a naked homo sapien.
It's not a matter of being "more evolved." It's a matter of how one "fits" where one is.
The relationship between a human and a kumquat is not the same as the relationship between a human and a grapefruit. Indeed, there are no "identical" relationships between any two organisms and any other organisms.
Of course you can belief what you want. However Chimps are very much alive, every bit as animate as we are. In fact all living organisms are equidistant from our inanimate beginnings. Even the lowly Amoeba dubia with a genome length of 670,000,000,000 bp, Amoeba proteus with 290,000,000,000bp, or the Stalked Adder's Tongue ( Ophioglossum petiolatum ) which has 160,000,000,000bp are quite alive and animate.
It is nice of you to acknowledge our inanimate pre-life and protolife precursors.
This changes my whole perspective on evolution!
The molecular evidence shows we diverged from Bonobos after we diverged from Pan troglodytes. This means we are more closely related to Bonobos.
By the way, your attempt at ridicule will not accomplish much unless it is meant to make you look arrogant.
Just for instance: The natural processes we call "the weather" produce a variety of ordered and self-assembled systems. E.g. tornados, hurricanes, jet streams, convection cells, etc.
But just like the thread the other day, you steadfastly refuse to provide a single iota of evidence to back up your statement.
Do you have an example of a scientific law that used to be a scientific theory?
How about the story made up by the ancient Hebrews?? It's hysterical!! It has talking snakes, magic fruit, a petulant god punishing people for building a tall building, a woman being turned into a pillar of salt, a worldwide flood... I wonder what they were smoking when they made up that story.
Where's the bonobo data?
You do like your strawmen don't you?
Any analogy to the genome as a program can only be taken so far. The genome is closer to a set of algorithms than to a recipe or blueprint but it is not exact by any means. A closer analogy would be that a non-regulatory gene is a subroutine that creates a subroutine. The gene creates a protein that does some work. In the original gene, a simple point mutation will either do nothing or cause the gene to create a different protein, which in turn will cooperate with other proteins to accomplish their work - at times producing a beneficial characteristic, sometimes a characteristic that is not affected by selection so is considered neutral, and sometimes it will create a characteristic that will be detrimental enough to the organism to kill it off before it replicates.
Solar radiation is a very rare cause for mutation. For a mutation to be inherited it has to be in the germ-line, either sperm or ova. No matter how many cells you have damaged by sunlight, if none of those cells happens to be a gamete, it will not affect inheritance and thus evolution.
The most common type of mutation to affect evolution are those that occur during meiosis, when the germ cells are first created.
So, let's take another look at your analogy:
"And solar radiation " -- Solar radiation can affect the germ line but does so infrequently. If it 'flips a bit' causing a point mutation it may or may not allow the organism to survive. If it does not survive it is taken out of the gene pool immediately. If the sunlight changes more of the germ cell then the likelihood of survival is dramatically reduced. However the affect solar radiation has on germ cells is almost nonexistent and as shown above is self correcting.
"as a means to add lines of code? " -- This presumes lines have to be added to produce anything novel. This just not so. Novel features and functions are always based on what already exists and are produced by modifying those existing characteristics. To accomplish this, the gene or group of genes that control the production of those characteristics need only be changed, whether that means deletion, modification or addition. This is because the DNA string length and content can result in one of many thousands of different proteins. If additional codons are needed, one of the more common mutations from replication errors is gene duplication, where an entire gene or group of genes is added to the genome length. That this happens regularly as is in evidence in the human genome where it has occurred multiple times.
Since this single line represents your entire argument it is evident that the last line has no meaning.
Got a cite for that? What I've read says the bonobo-chimp branch was shortly after their common ancestor diverged from the human line.
Actually, no you are not. Conservatism is anchored in rationality. Liberals reject reality in spite of the facts. ID'ers have MUCH more in common with liberals than conservatives - because they hold their conservative beliefs not due to a rational thought-out philosophy - but because of a fear of betraying their belief system.
ID'ers are just liberals with a different bent.
Precisely.
And ID is just a warmed-over PC with a right-leaning twist.
ID requires one to redefine words to suit a political agenda. ID casually discards all evidence that does not conform to existing dogma. ID employs conformity to a political agenda as the first criteria for evaluating evidence. ID is the ultimate expression of valuing feelings over reason.
This ID PC is every bit as silly and as dangerous as the original, and must be fought with just as much stength and enthusiasm.
With all the corrections my posts need, I get accused of doing that now.
I'm sure once he finds an intelligent post by you, he'll respond appropriately.
Just joking here. Don't take it seriously.
Evolution? No proof, just guesses. Well, maybe there is SOME proof, I mean, liberals do look like weasels.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.