Chimps, Humans Differ More Then Thought

DrLudicrous writes "CNN is carrying an article about a researcher at CalTech. Biologist Roy Briton undertook a comparison of human and chimp genomes, and came up with a 5% difference, versus the usual 2% cited in the literature. You can read the article at CNN. This seems to point out that chimps and humans most likely had a more distant ancestor than thought- but the results also need to be examined and redone by 3rd parties to ensure objectivity. Interesting stuff."

Comments

Re:We have a different number of chromosomes....

[esme]

Genetic difference is typically not measured in total genetic material -- they could have a lot of the same DNA sequences, but moved around within their chromosomes differently. So you can't just count up the chromosomes or the total ammount of genetic material. Genes actually get moved around a fair amount, so you can't assume that the DNA is just going to stay in the same order as one long string over millions of years. Genes get mixed up a lot during sperm production, including some genes that jump to other chromosomes.

Genetic difference is usually measured by comparing sections of the DNA that perform the same function (e.g., produce the same protein). The rationale for doing it this way is that if you assume that there is a common ancestor, then the section of DNA would have been identical when the divergence began. Since individuals who have the section that produces a required protein (e.g., hemaglobin) isn't going to survive, you can count on that section having been continguous in both animals since the genetic divergence began.

-Esme