This is a promising result that
tells us what existed and how it likely all worked as marine life was preparing
to go on land. It certainly provide a starting
point and nicely targets post marine DNA changes.
The revolution in DNA research
has barely begun and will begin to impact humanity directly inside a
generation. In particular, we do have a
specific alien DNA that can act almost like a Rosetta Stone.
It is that type of
revolution. Once we are there, all
babies will be upgraded almost as a matter of course and pregnancy itself will
be shifted to a birthing machine after the first trimester. The human body has never properly adapted to
the serious demands put on it for a full term birth. Thus technological intervention is highly
appropriate.
In the meantime, genome work is
building up a library of data that will allow clear understanding as we
progress.
Scientists decode DNA of 'living
fossil' fish
Malcolm Ritter, The Associated Press
Published Thursday, April 18, 2013 6:44AM EDT
NEW YORK -- Scientists have decoded the DNA of a celebrated
"living fossil" fish, gaining new insights into how today's mammals,
amphibians, reptiles and birds evolved from a fish ancestor.
The African coelacanth is closely related to the fish lineage that
started to move toward a major evolutionary transformation, living on land. And
it hasn't changed much from its ancestors of even 300 million years ago,
researchers said.
At one time, scientists thought coelacanths died out some 70 million
years ago. But in a startling discovery in 1938, a South African fish trawler
caught a living specimen. Its close resemblance to its ancient ancestors earned
it the "living fossil" nickname.
And in line with that, analysis shows its genes have been remarkably
slow to change, an international team of researchers reported Wednesday in the
journal Nature.
Maybe that's because the sea caves where the coelacanth lives provide
such a stable environment, said Kerstin Lindblad-Toh, senior author of the
paper and a gene expert at the Broad Institute in Cambridge, Mass.
Modern coelacanths make up two endangered species that live off the
east coast of Africa and off Indonesia
The coelacanth's DNA code, called its genome, is slightly smaller than
a human's. Using it as a starting point, the researchers found evidence of
changes in genes and in gene-controlling "switches" that evidently
aided the move onto land. They involve such things as sense of smell, the
immune system and limb development.
Further study of the genome may give more insights into the transition
to living on land, they said.
Their analysis concluded that a different creature, the lungfish, is
the closest living fish relative of animals with limbs, like mammals, but they
said the lungfish genome is too big to decode.
The water-to-land transition took tens of millions of years, with limbs
developing in primarily aquatic animals as long as nearly 400 million years
ago, by some accounts, and a true switchover to life on land by maybe 340
million years ago, said researcher Ted Daeschler.
Daeschler, curator of vertebrate zoology at the Academy of Natural
Sciences of Drexel University in Philadelphia, who didn't participate in the
new work, said genome research provides a way to tackle some previously
unanswerable questions in evolution.
He emphasized that DNA is best used in combination with fossils.
"This is a great detective tool," he said. "You might collect
DNA evidence at a crime scene, but you can't ignore the dead body.... With
paleontology, we have the dead bodies."
http://www.ctvnews.ca/sci-tech/scientists-decode-dna-of-living-fossil-fish-1.1243003#ixzz2Qpl2TdDw
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