The answer to why animals have sex may seem obvious: to have babies, of course!
And perhaps also for fun, as evidence suggests that bonobos, white-faced capuchin monkeys and some other animals experience carnal pleasure, including what appear to be orgasms.
- Which animal has the most sex?
- Do animals enjoy sex? These are the species seeking pleasure as well as procreation
But in evolutionary terms, sex is inefficient. A sexually reproducing population, in which only half can give birth, grows at half the rate of an asexual one in which everyone can. It is also costly to individuals, since you only pass on half your genes. Then there is all the palaver of having to find a mate.
So, why don't we all reproduce alone, like bacteria or aphids? Sexual reproduction involves shuffling up your genes with someone else's like two decks of cards, leading to endless potential combinations of characteristics. This results in greater genetic diversity between your offspring, which might grant them increased survival or adaptability to changing environments
