It is surprising how often doubling up of the gene content plays out
in biology. The most important is polyploidy. This has driven much
of our domesticated grains in particular. Since the most important
developments took place pretty well during the ninth millennia or so
BP and occurred in several separate locales, it is pretty difficult
not to presume deliberate human intervention.
Put another way it is possible to induce this and we have known how
for some time. The method could have been easily applied by humanity
at the time and place. The difficulty is that the knowledge pretty
well had to be communicated just when it became possible to engage in
agriculture in the post ice age world. That it did begs any
explanation except intervention itself and we are back to Noah.
Now we discover a similar occurrence kicked of vertebrate evolution
itself. This is coincidental but also suggestive. We really do have
to understand just how often this happens naturally. We also have to
understand what occurs when it happens naturally and just how much
variation can occur. It is a field of biological investigation whose
rewards have already been shown over thousands of years and simply
needs to be better understood.
I would like to know that this all occurs quite naturally and often
and all one has to do is keep one's eyes open in the field. This
will not get rid of the remarkable transition to agriculture that
took place in so many places unless we also show a global awareness
of agriculture form work on the continental shelf in the preceding
millennia.
Ancient genetic
'mistake' drove evolution
by Staff Writers
Dundee, Scotland (UPI) Jul 27, 2012
U.K. researchers say a
genetic "mistake" 500 million years ago triggered an
evolutionary pathway that eventually led to humans and many other
animals.
It happened when a
spineless creature on the ocean floor experienced two successive
doublings in the amount of its DNA, a major genomic event that
eventually led to the evolution of humans and other vertebrates, the
researchers said.
The results have been
both good and bad, researchers said. Good because the DNA doublings
boosted cellular communication so that our body cells are better at
integrating information; bad because breakdowns in that
communication, traced back to the same genome duplications, can cause
diabetes, cancer and neurological disorders.
"Organisms that
reproduce sexually usually have two copies of their entire genome,
one inherited from each of the two parents," researcher Carol
MacKintosh told Discovery News.
"What happened
over 500 million years ago is that this process 'went wrong' in an
invertebrate animal, which somehow inherited twice the usual number
of genes," said MacKintosh, a professor in the College of Life
Sciences at the University of Dundee.
"In a later
generation, the fault recurred, doubling the number of copies of each
gene once again."
"The
duplications were not stable, however, and most of the resulting gene
duplicates were lost quickly -- long before humans evolved,"
she said.
But some did survive,
MacKintosh and her team said.
They studied several
hundred proteins that work in human cells to coordinate responses to
growth factors and to the hormone insulin.
A biochemical analysis
of the proteins found they date back to the genome duplications
500,000 years ago.
