Going beyond Darwin

[Guest guest]

Dear colleagues,

The attached article published in today's Telegraph

is based an interview I did last week of Dr Marc Kirschner, Professor of

Systems Biology at Harvard Medical School, regarding a new approach to

explain Darwin's theory of evolution called 'facilitated variation.' I asked

him about the use of animals in laboratory experiments and he replied that

he respected animal rights and believed in humane treatment of animals but

also recognised the need to use animals in research. I also talked to him

about the ongoing debate on Creationism/Intelligent Design versus evolution.

He admitted there is a problem teaching evolution in the US due to religious

sentiments. I have always thought that accepting evolution would help us to

treat other animals better because it would entail us to accept that we are

animals ourselves which in turn would lead us to treat our brethren

respectfully. But one hundred and fifty years after Darwin's Origin of

Species, the evolutionary debate still goes on, I suspect because many of us

feel uncomfortable with the fact that accepting Darwin's theory would mean a

demotion of our perceived exalted status in the universe and would also

challenge the idea of a divine creator who made humans specially. Never mind

the fact that rigorous research over the years has provided incontrovertible

evidence in favour of Darwin's theory and has shown us to be apes(apes with

nuclear weapons albeit). A fact that renders creationism and belief in a

divine creator to be implausible and fanciful like unicorns floating in the

air or teapots orbiting Mars. But as Carl Sagan said, " You can't convince a

believer of anything; for their belief is not based on evidence, it's based

on a deep seated need to believe. "

Best wishes and kind regards,

 

http://www.telegraphindia.com/1080114/jsp/knowhow/story_8779452.jsp

Monday , January 14 , 2008

Going beyond Darwin

Marc Kirschner's theory of facilitated variation further explains Darwin's

evolutionary theory. ** reports Kirschner: re-examining

Darwin

 

Charles Darwin's theory of evolution is one of the greatest scientific

discoveries of all times. It is based on two premises — first, that all

living organisms are related to one another by common descent, and second,

the pattern of diversity and fitness of organisms to survive are dependent

on what he called 'natural selection.' Now Marc Kirschner, professor of

systems biology at Harvard Medical School in the US, is re-examining

Darwin's theory in the light of what he calls 'facilitated variation'.

 

Kirschner was in Calcutta last week to deliver the Acharya Jagadish Chandra

Bose Triennial Gold Medal Lecture at the Bose Institute.

 

" Darwin's theory comprises three sub theories, " remarked Kirschner. " A

theory of genetic variation and inheritance, a theory of natural selection

and a theory of how variation in the anatomy, physiology and behaviour of

the organism leads to changes in its genes. " Kirschner's theory of

'facilitated variation' does not prove Darwin's original theory to be

faulty, but it does augment it and provide a new way of looking at

evolutionary processes at work.

 

Citing species of Darwin's finches found on the Galapagos Islands as

examples of 'facilitated variation' at work, Kirschner stated that " many

small heritable beak variations accrued slowly in the different species to

create large observable differences. " Finches are small birds of 10-20

centimetres in length. Although they helped Darwin explain the theory of

natural selection, the evolutionary biologist failed to understand why these

closely related species have distinctly different beaks. He tried to explain

it away by saying that most of these birds were not finches, which later

turned out to be untrue.

 

The variations are small, but they allow the birds' upper and lower beaks,

adjacent skull bones and head muscles to co-evolve in small, selected steps.

Repeated selections would be needed to coordinate the numerous, small,

independent beak and head changes, all of which require genetic change.

 

Facilitated variation is a by-product of selection for effective

development. The neck length and the seven cervical vertebrae of mammals are

examples of this. While both humans and giraffes share seven cervical

vertebrae, the size of the vertebrae differs as a result of facilitated

variation in evolution. Kirschner is of the view that although Darwin knew

about the workings of facilitated variation, he lacked the tools to study

such changes in practice. " Details of embryonic processes and molecular

biology were unknown during Darwin's time, " he said.