Sperms aren't the mindless, flagellum-wielding, dolts you thought they were. They are wily
little devils with war on their nuclei.
[Music]
Hey dudes, Trace here with the lowdown on your sperms' struggles for DNews. Sperm
are the male gamete, the counterpart to the female's egg. When a sperm reaches the inside
of an egg, a zygote is created -- the first step on the path to a fetus. But to reach
that goal, a sperm have to overcome a lot of different problems - one being there are millions
of other sperm. They're like, WATCH OUT DUDE. Imma tryin' to get to the egg!
For instance, we've evolved what science calls sperm allocation. As the point of sex is to
get your sperm to the egg first and thus spread your genes, sperm allocation was one of nature's
ways of getting the most bang for your ... buck... IF a male believes his female sexual partner
has committed infidelity, or if he's simply spent a long while away from the partner,
his sperm count will increase when they pair up! The authors of a study published in Current
Directions in Psychological Science believe this is why males get lustful feelings after
being away from their partner; they want to make sure they can get as much sperm in there
as possible to compete.
Once inside the woman, sperm continue the struggle. This has to do with that creation:
sperm are formed based on HOW the species fertilize AND how much sexual competition
is present. It was assumed that the bigger the sperm, the faster they are. Bigger and
stronger is better? Right? Wrong. A study published in the journal Evolution uses Bonobos
as an example. These apes share almost 99-percent of their DNA with humans and have a lot of
sex with lots of partners. The competition has evolved sperm with bigger head and a smaller
tails. The larger sperm were actually SLOWER.
The researchers found only animals who fertilize OUTSIDE of their bodies have a large sperm
advantage. The shorter head and longer tail of fish and squid sperm were super fast and
thus got to the egg first. Yah bro!
Then there's the theory that there are two kinds of sperm - the goal scorers, and the
ones who play defense. Of the 250 million sperm cells released into the female reproductive
system, 27-percent are defective, right off the bat. The normally oval-shaped head is
spherical or quite pointy in parts, the tails are malformed or whatever. This theory of
so called "kamikaze sperm" also comes back to competition between mates. The idea
is that these malformed sperm hang back to block those from competing mates, thus ensuring
the first male's DOMINATION OF FERTILIZATION!!!
Since the hypothesis was proposed in the 80s, scientists have tried and failed to reproduce
their findings, so while we're pretty sure this isn't real, it's still being tested.
Most scientists now believe the 27-percent defect rate occurs because of poor quality
control in sperm creation... Which... is a little embarrassing. Dudes, this is our big
moment and we're half-assing it out there! 110-percent, c'mon!
Of the millions of sperms released, remember you were the fastest.
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