2006-06-06 06:38:27 · 9 answers · asked by ariostosilva 1 in Science & Mathematics ➔ Biology
There are organisms (fungi, mostly) with more than two genders. We call these "mating types." A mating type can usually mate with individuals of all other mating types except its own type.
Supposing there were many mating types at first, as rare ones get unlucky they go extinct, until there are only two left. These become male and female (if they have gametes of different sizes).
2006-06-06 07:47:53 · answer #1 · answered by Anonymous · 5⤊ 3⤋
Some life forms are able to reproduce without a second being (asexual reproduction) and thus may be considered by some to be genderless. Some display sexual organs of both sexes (hermataphytes) but usually only one is working (at least in 'higher' animals).
The main reason that we are of 2 genders is because of the way in which new organisms are created. Half of the genetic material for a new organism comes from the female and the other half comes from the male (through mitotic cellular division). Is it possible that there was once a time when it took 3 or more beings to procreate? Sure, but natural selection would kill them off quicker than those that needed fewer resources (partners in this case) to procreate.
2006-06-06 07:03:25 · answer #2 · answered by mawraight 2 · 0⤊ 0⤋
Some animals do only have one gender. They can reproduce with themselves. Also, some frogs can change genders depending on the environment and population in which they live. Two genders ensures genetic diversity to prevent genetic diseases and allow for natural selection. Three genders would make it way to complicated to reproduce (if all three parties had to be involved). You'd not only have to convince one person, but two, to reproduce with you!
2006-06-06 06:43:13 · answer #3 · answered by sparkles2U 3 · 0⤊ 0⤋
they will not be able to reproduce if there is only one gender, and probably, having three or more genders will ruin the balance of reproduction, do u get what i'm saying?
2006-06-06 07:11:57 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Not all animals have more than one gender some have only one like mammals and stuff. Sponges and cnidarians have more then one gender. You see, they have both sperm and egg cells. This way they can reproduce by themselves
2006-06-06 06:41:43 · answer #5 · answered by Anonymous · 0⤊ 0⤋
i read a book once about a race that had 3 genders. it was really odd. one of the genders was actually non-sentient and they kept them herded up or something weird like that.
2006-06-06 06:41:53 · answer #6 · answered by rishathra7 6 · 0⤊ 0⤋
just to tick u off lol. probibly to make things easier with more than 2 genders what would the reproductive system look like. it would look crazy so it is to simplify matters.
2006-06-06 06:48:21 · answer #7 · answered by nearta 1 · 0⤊ 0⤋
gender as in male/female? do i understand correctly? maybe b/c there is only male/female? maybe i don't get what your asking. hmmm...
2006-06-06 06:41:41 · answer #8 · answered by nurdburd13 2 · 0⤊ 0⤋
Many have more... including humans.
2016-05-12 06:42:58 · answer #9 · answered by Anonymous · 0⤊ 0⤋