Friday, March 4, 2011

A video to watch before I publish the two posts I promised. It's about our closest living non-human cousins.


"They're just like us."

"From over a million then to less than three hundred thousand today."

"We're part of the animal kingdom, not separate from it."

The comparison of their DNA sequences to our DNA sequences is the strongest possible evidence for our evolutionary relationship with chimps. There is no scientific evidence more powerful. The Bible thumpers could care less about these magnificent creatures because their existence makes Jeebus cry.

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Why are there two chimpanzee species?

From wikipedia:

The bonobo is endangered and is found in the wild only in the Democratic Republic of the Congo. Along with the common chimpanzee, the bonobo is the closest extant relative to humans. Because the two species are not proficient swimmers, it is possible that the formation of the Congo River 1.5–2 million years ago led to the speciation of the bonobo. They live south of the river, and thereby were separated from the ancestors of the common chimpanzee, which live north of the river.[10]

Analysis of Chimpanzee History Based on Genome Sequence Alignments

Population geneticists often study small numbers of carefully chosen loci, but it has become possible to obtain orders of magnitude for more data from overlaps of genome sequences. Here, we generate tens of millions of base pairs of multiple sequence alignments from combinations of three western chimpanzees, three central chimpanzees, an eastern chimpanzee, a bonobo, a human, an orangutan, and a macaque. Analysis provides a more precise understanding of demographic history than was previously available. We show that bonobos and common chimpanzees were separated ~1,290,000 years ago, western and other common chimpanzees ~510,000 years ago, and eastern and central chimpanzees at least 50,000 years ago. We infer that the central chimpanzee population size increased by at least a factor of 4 since its separation from western chimpanzees, while the western chimpanzee effective population size decreased. Surprisingly, in about one percent of the genome, the genetic relationships between humans, chimpanzees, and bonobos appear to be different from the species relationships. We used PCR-based resequencing to confirm 11 regions where chimpanzees and bonobos are not most closely related. Study of such loci should provide information about the period of time 5–7 million years ago when the ancestors of humans separated from those of the chimpanzees.

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