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Why are there two genders (male & female) for almost all species?

Why are there two genders (male & female) for almost all species?

Wouldn't it be more efficient if there was only one gender, like a unisex-gender where anyone can mate with anyone?

Or perhaps not need to mate at all, but self replicate?

5 Answers

  • 1 decade ago
    Favorite Answer

    It's better for evolution.

    The sexual reproduction makes it easier cause the DNA of both subjects recombines.

    In the asexual reproduction this doesn't happen, so the evolution is slower, very much slower.

    However, some sexual species reproduce by having both genders on a same individual, which one mates with itself. An example of this are the flowers.

  • 1 decade ago

    There are species that have both testes and ovaries, and they are both male and female. There are some plants that have male and female parts in the same flower, or they have both male and female flowers. Some fish can be males and then as they grow, become females.

    The reason behind sexual reproduction is the exchange of mutations. If an individual can obtain the mutations of other individuals and pass it on to its offsprings, then genetic diversity has increased. At the population level, there is a greater degree of genetic variation than in clonal species. The greater genetic diversity is a hedge against any new disease that may crop up. For example, the plague, which devasted Europe in the Middle Ages, did not completely wipe out the population, because some Europeans had genes that made them resistant to the disease. Similarly, chimpanzees had been devasted by AIDS, but there were a few individuals that were resistant to the virus and they survived. Without genetic diversity, a species is more vulnerable to diseases and may become extinct.

    If the advantage of sexual reproduction is to exchange genes, then having separate sexes forces these individuals to exchange genes by mating with other individuals. It makes self-fertilization impossible, ensuring that genetic diversity is always maintained. Even though it means reproduction is not possible if only a single individual remains, this strategy of separating the sexes has proven successful overall and it is widespread among sexually reproducing species.

  • Anonymous
    5 years ago

    Well I'd say gender identity and sexual preference are irrelevant because we have the ability to understand how we can procreate if we WANT to, as opposed to being driven by only instinctual desires like in the animal kingdom. Even if everyone in the world was gay, for example, we would still procreate because we know how. But honestly, I really don't understand the relevance of your argument. Why do you assume that nature always works in favor of procreation? In fact, if people stopped procreating for a while, it would probably do some good. The population is getting way out of hand.

  • 1 decade ago

    for multicellular eukaryotes yea, but the bast majority of species on earth are bacteria and archea.

    having two sexes means mixing of the gene pool, and improves the capacity for advantageous traits to spread in a specie's population.

    for example. in order for bacteria to gain a new trait it would have to exchange genes via a pilus(almost like sex) or duplicate itself to contribute its gene to the gene pool- however, it still suffers from the competition of other bacteria of its species. but this is acceptable because of the high rate of replication- and extreme level of compeditiveness. so say the gene was for resistance to an antibiotic or a certain condition- when it arises the rest die off and genes become selected for and the new population has evolved. but in slow growing organisms like ourselves, which are complex and which have long lifespans(and many many ways to die) species which reproduce sexual gain a much greater deal of variation(not all of which are advantageous, but if the whole population becomes much more diverse genetically, natural selection has alot more to select from)

    imagine if we were self replicating creatures, each line of individuals would remain relatively the same over time, and in order to increase the number of persons with certain new gene mutations(whether good or bad) that individual would have no way to do so unless it were to reproduce more- which it cant do very much of within its lifespan--due to size restrictions and our capacity to build biomass. and evolution would only take place whenever there is a massive decimation of the population to allow the survivors to pass on their genes and fill their place such that their 'survivor genes' become the new norm of the population. for creatures like us, this method of evolution would be drastically slower.

    its an interesting phenomena for larger organisms thats the subjectof some study, and though my explanation may be poor i believe this is the most prominent theory behind why sexually reproducing organisms have gained a massive advantage among the larger multicellular eukaryotes.

    -there are a few species of newts i believe that reproduce by self replication.. not sure how that happened.... and a number of species are also hermaphrodites, or capable of self fertilization when a mate isnt present.

    Source(s): 3rdyear microbiology major
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  • 1 decade ago

    All species don't have male and female.

    male and female ( 2 parents ) are required in sexual reproduction, so in that case 2 person ( one male and one female) is required

    THose producing asexually don't have 2 parents. they have one parent.

    Earthworms are hermophordite. These species don't have male of female . They are transgendered.

    Source(s): .
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