16 JUL 2013 by ideonexus
DNA Divergence is in How You Count
It’s a common misconception that chimp DNA
differs from Homo sapiens sapiens genes by only a
single percent, but this number is apocryphal. In actuality,
the degree of similarity of human and chimp
genetic code depends mostly on how you count.
Since all complex organisms from Earth possess
great swaths of junk DNA inherited from a distant
common ancestor, there tends to be startling similarity
between many organisms. Sure, humans are like
chimps—but they’re also like flatworms and fruit...Folksonomies: dna genetic drift
Folksonomies: dna genetic drift
There's much more to the differences between Chimps and Humans than counting genes.
16 SEP 2011 by ideonexus
Vestigial GLO Pseudogene
And the evolutionary prediction that we’ll find pseudogenes has been
fulfilled—amply. Virtually every species harbors dead genes, many of them still active in its relatives. This implies that those genes were also
active in a common ancestor, and were killed off in some descendants but
not in others. Out of about 30,000 genes, for example, we humans carry
more than 2,000 pseudogenes. Our genome—and that of other species—
are truly well populated graveyards of dead genes.
The most fam...Used to produce Vitamin C, alive in most mammals, but dead in humans, primates, and others.
16 SEP 2011 by ideonexus
Birds to Reptiles
Because reptiles appear in the fossil record before birds, we can guess
that the common ancestor of birds and reptiles was an ancient reptile,
and would have looked like one. We now know that this common ancestor
was a dinosaur. Its overall appearance would give few clues that it was
indeed a “missing link”—that one lineage of descendants would later give
rise to all modern birds, and the other to more dinosaurs. Truly birdlike
traits, such as wings and a large breastbone for anchoring ...Folksonomies: evolution
Folksonomies: evolution
Birds and reptiles share many resemblances, meaning they have a common ancestor, which is dinosaurs.
19 MAY 2011 by ideonexus
Species Divisions are Complicated
Zoologists have traditionally divided the vertebrates into classes: major divisions with
names like mammals, birds, reptiles and amphibians. Some zoologists, called 'cladists',* insist that a
proper class must consist of animals all of whom share a common ancestor which belonged to that
class and which has no descendants outside that group. The birds would be an example of a good
class. All birds are descended from a single ancestor that would also have been called a bird and
would have sha...The ancestors are birds are reptiles, but in the fossil record where do we draw the line between them?