OK, been on this site for a while hence my baddie points if not my goodies. However, can't find a serious science section.
New Scientist 24th Jan 2009
'IN JULY 1837, Charles Darwin had a flash of inspiration. In his study at his house in London, he turned to a new page in his red leather notebook
and wrote, "I think". Then he drew a spindly sketch of a tree.'
'"For a long time the holy grail was to build a tree of life," says Eric Bapteste, an evolutionary biologist at the Pierre and Marie Curie
University in Paris, France. A few years ago it looked as though the grail was within reach. But today the project lies in tatters, torn to pieces by
an onslaught of negative evidence. Many biologists now argue that the tree concept is obsolete and needs to be discarded.'
'So what happened? In a nutshell, DNA. The discovery of the structure of DNA in 1953 opened up new vistas for evolutionary biology. Here, at last,
was the very stuff of inheritance into which was surely written the history of life, if only we knew how to decode it.'
'The problems began in the early 1990s when it became possible to sequence actual bacterial and archaeal genes rather than just RNA. Everybody
expected these DNA sequences to confirm the RNA tree, and sometimes they did but, crucially, sometimes they did not. RNA, for example, might suggest
that species A was more closely related to species B than species C, but a tree made from DNA would suggest the reverse.'
'Which was correct? Paradoxically, both - but only if the main premise underpinning Darwin's tree was incorrect. Darwin assumed that descent was
exclusively "vertical", with organisms passing traits down to their offspring. But what if species also routinely swapped genetic material with
other species, or hybridised with them? Then that neat branching pattern would quickly degenerate into an impenetrable thicket of interrelatedness,
with species being closely related in some respects but not others.'
'We now know that this is exactly what happens. As more and more genes were sequenced, it became clear that the patterns of relatedness could only be
explained if bacteria and archaea were routinely swapping genetic material with other species - often across huge taxonomic distances - in a process
called horizontal gene transfer (HGT).'
How does this impact on the scientific debate between the accuracy of science and assisted design. We now have more possibilities than just genetic
mutations, could tides, the moon, the sun, Jupiter, a lonely fish getting infected like a cat et al have a hand in this?
Just a thought.......
[edit on 23/1/2009 by redled]