Evolution Question

[Maynard]

I'm sorry if this has been asked and answered before but while reading an essay on Winston Churchill The Medal of His Defeats by Christopher Hitchens. He mentioned a conclusion made by Stephen Jay Gould, after reviewing the records of some fossils, which was that if the "tape" of evolution could be rewound and run again, it would not "come out" the same way. There was no further explanation of this, so I was wondering if anyone here, in sort of layman's terms could explain why this would be so.

[Mujer Libre]

Originally posted by [email protected] 24 2006, 03:01 AM
I'm sorry if this has been asked and answered before but while reading an essay on Winston Churchill The Medal of His Defeats by Christopher Hitchens. He mentioned a conclusion made by Stephen Jay Gould, after reviewing the records of some fossils, which was that if the "tape" of evolution could be rewound and run again, it would not "come out" the same way. There was no further explanation of this, so I was wondering if anyone here, in sort of layman's terms could explain why this would be so.
That's because the variations that allow natural selection to act are based on random mutations, occuring at random points in DNA. So if we rewound the tape it would be extremely unlikely that the same mutation would occur twice, and almost infinitely unlikely that the same mutations would occur over and over again- since speciation is based on the cumulative effects of selection.

I hope that makes sense!