2006-09-18 10:13:34 · 6 answers · asked by Evangelina V 1 in Education & Reference ➔ Higher Education (University +)
Good question! hahahaha.
I hope you're not seriously expecting a good answer!
2006-09-18 10:16:50 · answer #1 · answered by TiM 4 · 0⤊ 1⤋
As it turns out, there don't have to be only TWO genders. Simpler organisms have sexual reproduction without gender distinctions at all, which represents the ancestral state. The next stage can still be found today; certain fungi have hundreds of genders, and can mate with any gender except their own. It is easy to see how genders can get lost from this system, until only two remain.
At the same time, or shortly thereafter, maleness (small gametes) and femaleness (larger gametes) inevitably arise from a two-gender system due to cheating by the future male gender. Males quickly evolve because the selection pressure to produce many small, mobile gametes is intense. The other gender must begin to at least double the size of their gamete (the egg) to compensate.
Thus is gender evolved. This has happened in several different lineages over the past billion years or so.
2006-09-19 06:43:12 · answer #2 · answered by Anonymous · 1⤊ 0⤋
The first life consisted of single celled organisms which simply reproduced by making copies. This keeps the gene pool very shallow. There isn't much variation within a gene pool. By having a system in which two organisms combine their genetics, the gene pool becomes more diverse, or deep. The more diverse a gene pool is, the easier and faster evolution can work.
The first organisms to combine genetics to reproduce created a more diverse gene pool, which was a positive attribute, which lead to higher species faster.
Obviously, when you create a species based on two different organisms coming together to reproduce, gender happens.
2006-09-19 05:08:29 · answer #3 · answered by Take it from Toby 7 · 1⤊ 0⤋
Ahurm.... that's my throat being unclogged... anyways, gender is determined while you are a fetus, because your tiny body either starts to make male hormones or no hormones.... thus a girl. But as for the evolution? There's no clear answer...
2006-09-18 10:22:09 · answer #4 · answered by Anonymous · 1⤊ 1⤋
Well, there's always been gender between the more developed organisms because it's essential to sexual reproduction.
2006-09-18 10:19:12 · answer #5 · answered by yofatcat1 6 · 0⤊ 1⤋
Heterogamy evolved from isogamy.
Once you had heterogamy, you could evolve sexual dimorphism.
2006-09-18 10:21:45 · answer #6 · answered by Anonymous · 0⤊ 1⤋