Tuesday 4 November 2014

How the Giraffe got its long neck


‘Please don’t mock us,’ said the Giraffe t-
o someone who thought their necks daft;
‘a diet arboreal
needs six foot or more. We all
think it’s quite rotten you laughed.’

 

Please excuse excruciating rhymes and enjambments.

Superficial consideration of the giraffe has led many people into the misunderstanding of evolution known as Lysenkoism. ‘Well, you see,’ these people explain to their benighted children, ‘some giraffes managed to reach up higher and get more leaves to eat, so they lived long enough to have baby giraffes, who inherited their parents’ stretched necks, and so over the centuries…’

Bullshit. Acquired characteristics are not inherited. What in fact (if you accept that Darwin’s theories correspond to fact) happens is that the parents’ genes are subtly (or grossly) altered by what Darwin called ‘Chance variation’, which we now know to be atomic radiation reaching us from the sun. If the affected gene happens to be the one labelled, as it were, ‘Neck length’, then the affected giraffe’s children will be born with long necks, so that they will stand a better chance of surviving to child-bearing age. Since they have inherited their parents’ altered genes, their children too will have longer necks, and so it goes on. In the case of giraffes the cosmic radiation part of the story probably happened many times, sometimes leading to yet longer necks, sometimes to short-legged or two-headed giraffes or other Chernobylesque horrors. I don’t know how many thousand years it took the giraffe to get its long neck, but the point is that neither its nor its parents’ personal neck-stretching exercises had anything to do with it.

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It was on the 4th of November 1922 that Howard Carter found the entrance to Tutankhamen’s tomb.

 

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