Complexity of gene codes (Introduction)

by George Jelliss , Crewe, Sunday, August 15, 2010, 20:09 (5213 days ago) @ David Turell

I thought this comment on a discussion on the Dawkins forum might be of interest. It estimates the enormous number of generations in the process of evolution from the simplest cell to humans. More than enough for chance and natural processes to evolve all manner of complexity.-http://richarddawkins.net/discussions/499667-how-many-generation-estimated-from-first-cell-to-modern-human-How-many-generation-estimated-from-first-cell-to-modern-human?-In The Ancestors Tale Richard Dawkins gives an estimate of 
how many generations have gone between each branch point concerning 
the human line (which turns into the 'ape line' then the 'mammal line' 
then... etc.) to us modern day humans (there are about forty such 
branch points on our line - surprising no?). So the fisrt branch point 
is between us and chimps, 250 thousand generations ago (which spans 
6 million years). Reptiles and birds branched off at 310 million years 
ago, 170 million generations ago. Of course, the average generation 
time for a human is something like 20 years, whilst mouse might be 
only about 2 years - so that has to be factored in (and since we are 
dealing with long extinct animals, some guesswork is required).-Anyway, the last branch point, which Dawkins ventures a guess at the 
amount of generations past, is at the branch point between humans 
and protostomes (worms, molluscs, insects and crustaceans etc.) 
This is a little after 'phylems to be' such as plants, animals and 
fungi have appeared. Dawkins estimates about 310 million genertions 
have passed in that 600 million year(!) gap.-So Dawkins deosn't even try to guess at how many generations have 
gone between us and our single celled ancestors. Were are probably 
talking anywhere between 1 and 4 billion years of single celled life. 
Some single celled animals today have a geration time of a few hours. 
How many generations can you pack into a few billion years, given a 
generation time as short as that?-Hell if I know, but the margin of error would be collosal.-Addition: Assuming two and half billion years of single celled life, 
with an average generation time of 6 hours. There would have been 
3'650'000'000'000 (3.65 trillion) generations before you even start 
with multicellular life.

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GPJ