reproduction

achilles12604 · Post by **achilles12604** » Thu Aug 02, 2007 3:53 am

Reproduction is fundamental to the existence and continuation of all species. Natural selection is the process by which favorable traits that are heritable become more common in successive generations of a population of reproducing organisms, and unfavorable traits that are heritable become less common.

Therefore, what is the explanation for internal fertilization? After all isn't asexual reproduction faster and more effective than internal fertilization? What caused internal fertilization to become standard among complex life forms? Wouldn't this be a disadvantage and therefore weeded out in natural selection?

Furrowed Brow · Post by **Furrowed Brow** » Thu Aug 02, 2007 5:19 am

If you are a species that also finds some advantage investing the time and energy protecting your young, then it is a potential advantage to carry your unborn around with you, otherwise you are stuck to guard one place. This does not matter so much if there is plenty of food nearby, or you are a species that can go without food for long periods. However, where morphology and environment dictate some organisms would have found advantage carrying theirs eggs around with them, and then there is a limitation upon the number of eggs that can be carried. So any clear advantage of external fertilisation is lost as soon as a species gets paternal/maternal. A trait itself dicated by the level of predation upon their eggs.

MikeH · Post by **MikeH** » Thu Aug 02, 2007 9:39 am

I think it has to do with the combination of DNA creating greater variety than asexual reproduction. Greater variety then leads to a better chance of surviving disease, etc...

Undertow · Post by **Undertow** » Sun Sep 23, 2007 9:42 pm

Making clones of yourself makes whole populations suceptible to being topped by environmental difficulties rather than just the individuals that lucked out on the sexual recombination lottery. Sexual recombination makes this effect non-existant, so it's beneficial on this basis. How and under what circumstances sex evolved is still an active area of research for evolution and is proving a mysterious problem, as I understand it.

Goat · Post by **Goat** » Sun Sep 23, 2007 10:42 pm

Undertow wrote:Making clones of yourself makes whole populations suceptible to being topped by environmental difficulties rather than just the individuals that lucked out on the sexual recombination lottery. Sexual recombination makes this effect non-existant, so it's beneficial on this basis. How and under what circumstances sex evolved is still an active area of research for evolution and is proving a mysterious problem, as I understand it.

I think they have more that a little idea, since there are examples of the precursor of sexual reproduction that is a link between asexual and sexual reproduction.

Here is some info about it

http://www.dorak.info/evolution/sreprod.html

Undertow · Post by **Undertow** » Sun Sep 23, 2007 11:11 pm

goat wrote:
Undertow wrote:Making clones of yourself makes whole populations suceptible to being topped by environmental difficulties rather than just the individuals that lucked out on the sexual recombination lottery. Sexual recombination makes this effect non-existant, so it's beneficial on this basis. How and under what circumstances sex evolved is still an active area of research for evolution and is proving a mysterious problem, as I understand it.
I think they have more that a little idea, since there are examples of the precursor of sexual reproduction that is a link between asexual and sexual reproduction.

Here is some info about it

http://www.dorak.info/evolution/sreprod.html

Interesting read, thanks.