Comment: 07:24 - 08:22 (00:58)
Source: Annenberg/CPB Resources - Earth Revealed - 11. Evolution Through Time
Keywords: "Jamie Webb", "sexual reproduction", cell, "asexual reproduction", clone, DNA, mutation
|
Our transcription: Prior to sexual reproduction organisms reproduced by division of cells.
If you have simple division, asexual reproduction, you're essentially having the production of clones of the original organism carrying the original organism's DNA as long as there's no mutation involved or anything like that.
Essentially there's very little chance with the exception of mutation for evolution because you simply have the same organism being cloned generation, after generation, after generation.
When you finally have sexual reproduction, you have, for the first time, the chance for DNA to combine, to have a brand new organism that contains some of each of its parents, of course, but is itself different from either parent.
So you have a whole new ability for these organisms to change.
|
Geology School Keywords
|
