Quote:
Originally Posted by Lifer
was it a boy chicken or a girl chicken?
"..theres the rooster, the hen, and the chicken. the rooster goes with the chicken. who's having sex with the hen?"
- Frank Costanza, "Seinfeld"
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The origin of sex isn't a question that can easily be answered on a message board, but in fact there have been studies into it. I'll give a brief rundown of how and why sex evolved just in case anyone is interested.
First of all, why is sex even needed? Some organisms are asexual, while others only have one sex. They basically clone themselves. There are some reasons as to why sex would have evolved in the first place. First of all, sex can create genetic variation. This can aid in the passing on of positive traits, or the removal of negative traits. Second, sex helps with DNA repair. Third, sex can cause what is known as hybrid vigor, which adds increased characteristics in hybrids that can strengthen a species. And finally, sex allows different genes to be swapped which aids in the fighting of disease and parasites. This is known as the Red Queen hypothesis//en.wikipedia.org/wiki/Red_Queen
http://en.wikipedia.org/wiki/Red_Queen
. These are just some of the possible reasons as to why sex is beneficial and would have been selected for.
If we look at sexual reproduction, there are many options.
1. Gametes may be different, like sperm and eggs, or the same.
2. Adults may produce both sperm and eggs, or just one.
3. If an organism can produce both sperm and eggs, it may or may not be able to fertilize itself.
4. Species may have more than just two genders.
http://news-service.stanford.edu/new...ection219.html
5. Males and females might be the same or different.
6. The males and females may or may not have different genitalia.