After the dinosaurs were wiped out 65 million years ago by, um, well... whatever wiped them out,
mammals (originally tiny mouse-like creatures) suddenly went
through a dramatic explosion of speciation, rapidly diversifying in
shape and size to fill the vast number of ecological niches that had
been suddenly vacated.
Evidence of this explosion is written on the genes of every mammal
alive today, all of whom share a surprisingly high amount of DNA from
this extinct species and some remarkable recent research
using a segment of DNA from 19 different mammalian species has been
able to reconstruct what the equivalent sequence of the ancestor
species' DNA would have looked like. The reconstruction is claimed to
be more than 98% accurate.
While generating a sequence of a million base-pairs is still a far cry
from reconstructing the DNA of an entire creature, the implications of
this research are quite exciting because it has the potential of
enabling us to work out the most likely trajectory of mutations our
genome took as it rolled through mammalian history. This offers us
opportunities to test the genetic capabilities of our ancestors, their metabolisms, their ability to see colour
and so on which is something never thought possible before because
fossilized DNA cannot be extracted from bones more than 50,000 years old. This
new technique allows us to go back 80 million!
