Back when you were in your junior high school years, your biology teacher probably have taught you a bit about your reproductive system — along with other organisms’ which chances are you weren’t really paying attention to. Assuming so, you might recall that there are two types of reproductive system: sexual and asexual. We humans reproduce by having sex, no shit Sherlock (note that the objective to reproduce can only be achieved if two different sexes are involved, so, sorry homos and lesbians).
That being said, why our species evolved to reproduce sexually? I mean, take a look at amoebas. They just split themselves from 1 into 2 into 4 into 8 and so on, thus producing more offspring (if you can say so). Or planaria worms that when you cut 1 into 2 separate parts, each part can grow up to become an adult, resulting in 2 adult worms. Both examples are able to multiply up to a huge number in a relatively short time span. On the other hand, we humans and countless other species must first find a partner to mate with (which is not an easy task, well, at least for me personally). Then followed up by pregnancy phase, which requires protective behavior from both male and female individuals (well, at least the female). For example, an elephant’s pregnancy phase is normally 2 years and a human’s is 9 months. That’s a long-ass time compared to previously mentioned asexual beings. No need to mention about the process of giving birth which somehow, for some reason, is significantly painful to humans.
The facts presented before might seem to stand against the concept of interaction between evolution and natural selection. Yet, here we are. The only species on Earth capable of causing climate change and mass extinction of other countless species. Hence the question; why sex?
First of all, let’s dive into the definition of sex itself (as a verb of course). From biological point of view, sex is an activity where two individuals with different sexes (as a noun) combine their genetic materials in order to produce offspring. From this definition, we can already highlight the difference between us and, say, amoebas. They don’t combine genetic materials; they make copies of their own. It means that all of them are more likely to be identical in terms of genes, unlike us which obviously aren’t so identical with other humans. This is important to defend our species against an enemy; diseases. A colony of organisms that are genetically identical is more prone to be annihilated by a single type of disease, simply because all of them are the same. The way to kill the next organisms would be just the same as the previous one. Thus, the organism that cause the disease have no need to mutate or adapt to any different biological defense. Humans are less likely to fall victim to such unfortunate circumstances since gene combinations for each individual is unique.
Next, organisms that reproduce asexually tend to live shorter life. This, according to evolution, is because they essentially may die after the main goal of living creatures — rising numbers had already been achieved. Shorter lifespan also requires less sophisticated body features. Humans and other sexually reproducing organisms tend to live longer at least to accommodate the process of growing up to be sexually mature along with the previously mentioned pregnancy phase and giving birth. Thus resulting in the need of more complex survival kit. Take a look at your body and your brain’s ability, you’ll get it.
Last but not least is the hormonal change caused by the mating process itself. Humans tend to create different emotional bond with their partners prior, during, and after having sex, especially during and after. This kind of emotional bond normally reinforces human parents to take care of their human fetus which will eventually become a human infant and grow up, ready to do what his/her parents did. Combine this emotional bond, hormonal change, along with sophisticated brain and boy design and you can’t go wrong…well, at least most of the time.
So there you go. A “pop science”-ish, very brief, in a nutshell deductive analysis on why we humans evolved to reproduce by having sex along with the benefits of such design. I think the emotional and hormonal part also explains a bit why we enjoy mating process — at least if done in consensual manner, especially from the female side. Just, be aware of STDs and…uhh…”unplanned events”, so to speak. So, go! Mate with the right partner and pass on the best possible gene combinations. Use protections if you’re not planning to have a junior anytime soon. Regardless of the outcome, who doesn’t enjoy a brief glorious moment of climax in bed, eh? Or kitchen…or balcony…or any other inappropriate choice of venue considering the “activity” taking place…
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Source: Anything by Hank Green from both SciShow and Crash Course Youtube channel
