The two lice lineages diverged
at about the time that a genetic split occurred between H.
A small genetic analysis 5 years ago found some support for the idea that indigobirds diverged
from other birds much more recently than their hosts did, a finding that favors the song scenario over cospeciation of indigobirds and hosts.
The researchers study Astyanax mexicanus, a freshwater fish that has diverged
into a sighted, surface-dwelling form and a blind, cave-dwelling form.
He examines who our closest living relatives are and when we diverged
from them along our evolutionary path.
Living chimps have diverged
genetically from that common ancestor about as far as people have, the researchers add.
That uniformity suggests that although distributed from Honduras to Papua New Guinea today, the parasites diverged from a common ancestor at some time within the past 23,000 years, probably less.
If, as earlier data suggest, the two Plasmodium species split 6 to 10 million years ago when chimps and humans diverged, the uniformity of mitochondrial DNA among the P.
By comparing the human and fish genomes, says Hawkins, scientists can find DNA sequences that evolution has preserved in starkly different animals, ones whose lineages diverged
around 400 million years ago.
They conclude that the genetic differences between the San and the Hadzabe are greater than any other pair of populations in the world, indicating that the two groups diverged
at the dawn of humanity.
The sounds differ so much, he says, that he now suspects they evolved only after the lineage of river dolphins diverged
from marine dolphins.
Section of a so-called DNA backbone seem unchanged since the two strains diverged
However, by the time the branches meet on the far side of the obstacle, the creatures in the opposite branches have diverged
so much that they no longer interbreed.
However, the new work relied on a sensor that was too narrow to detect cases in which protons might have diverged
widely, Thoennessen says.