Posted on 09/02/2005 5:54:45 AM PDT by nfldgirl
By Clive Cookson, Science Editor Published: August 31 2005 18:46 | Last updated: August 31 2005 18:46
The first detailed genetic comparison between humans and chimpanzees shows that 96 per cent of the DNA sequence is identical in the two species. But there are significant differences, particularly in genes relating to sexual reproduction, brain development, immunity and the sense of smell.
An international scientific consortium publishes the genome of the chimpanzee, the animal most closely related to homo sapiens on Thursday in the journal Nature. It is the fourth mammal to have its full genome sequenced, after the mouse, rat and human being.
Some of the scientific analysis of the 3bn chemical “letters” of the chimp’s genetic code focused on its remarkable closeness to the human genome. After 6m years of separate evolution, the differences between chimp and human are just 10 times greater than those between two unrelated people and 10 times less than those between rats and mice.
But most scientists are concentrating on the differences. The vast majority of these probably have little biological significance, said Simon Fisher of the Wellcome Trust Centre for Human Genetics at Oxford: “The big challenge for the future is to pinpoint the tiny subset of differences that account for the origins of unusual human traits, such as complex language.”
The preliminary evidence suggests that the outstanding size and complexity of the human brain owes less to the evolution of new human genes than to the different way existing genes produce proteins as the human brain grows in the foetus and during infancy. Genes for transcription factors - molecules that regulate the activity of other genes and play a vital role in embryonic development - are evolving more quickly in humans than in chimps.
Three key genes involved in the human inflammatory response to disease are missing in chimps, which may explain some of the differences between the two immune systems. On the other hand humans have lost a gene for an enzyme that may protect other animals against Alzheimer’s disease. External website: Read Nature’s interactive report on the chimp genome Click here
The clearest differences to emerge from the analysis are in the Y (male) sex chromosome. While the human Y chromosome has maintained its count of 27 active gene families over 6m years, some have mutated and become inactive on its chimp counterpart.
This finding contradicts the popular view that the human Y chromosome is withering away because it has no genetic “mate” with which to swap genes - a process that repairs damaged DNA on other chromosomes. Presumably an alternative repair mechanism has evolved in humans but not in chimps.
David Page of the Whitehead Institute for Biomedical Research suggested that mating habits in the two species might explain the difference. Because male and female chimps mate with multiple partners there is stronger selective pressure on sperm-producing genes and conversely less pressure on evolution to preserve other genes on the Y chromosome in the apes than in largely monogamous humans.
I descended from a mouse.
Well, there you go. That just proves that chimpanzees evolved from humans.
I like that this report focuses on the differences.
Similar does not mean the same.
It is long been know that other animals and humans have very similar genetic structures. If you do the gene sequencing between humans and lets say a horse, you will find many of the same gene sequences as well.
The big and major difference is that 4%. What the article fails to detail is that the 4% accounts for extended brain functions, speech, reasoning, etc. Those make big differences in the grand scheme of things.
Some animals are more equal than others...........and so are some people...........
Maybe that is why I make funny noises when I scratch my armpits.
Silicon used for making computer chips must be pure to something like 12 decimal places (99.999 999 999 999% pure). When I was in college taking physical electronics (dealung with a lot of quantum theory) one of the excercises was to see what effect contamination of one part in a BILLION would make. The result was that it would basically render the batch unuseable.
I suspect that 4% difference between chimps and humans is MUCH more than they are willing to admit. Literally it is the difference between constructin a vessel that will take men to the moon and back and swinging in trees and then picking fleas off each other's back (sorry if I offended tre swinging, flea picking 'Rats).
Of the 5,000 best-known human genes, 75% have matches in the worm.
Ref: 2000 Election, 2004 Election
4% is huge. All species on the planet are very genetically similar simply because we all exist in the same carbon/oxygen/nitrogen environment, and are carbon-based ourselves. We wouldn't be able to survive on the planet otherwise.
96% really means nothing when 90% of the similarity is based on the characteristics animals need just to exist on Earth.
That's f*ckin gross, don't ever do that again..
98% identical in New Orleans.
Fortunately it looks like the divorce will happen before there are kids involved.
Hey, evolution is a long process, remember? Some apes haven't quite caught up yet..
True, but the difference may be small enough that we will soon have bioengineered chimps that are obviously self-aware and that communicate with human-like language.
All kinds of ethical hell is gonna break loose then.
This one, number 57, seems of interest.
Whoever told you that somehow human DNA is "50% identical" to that of a tomato, or that human and oranges "share 75% of DNA", either didn't know what in the heck they were talking about, or were being dishonest.
Do not be so confident. There are indirect ways of raising chimps to higher linguistic levels, like genetically lengthening their adolescence. You don't have to be able to understand or engineer even 10% of that 4% to make some serious monkey business.
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