It seems that people evolve by changing slightly and so becoming more suited to their enviroment, and being able to find a mate.
Have sperm evolved to swim faster,
If so is this the only way they could change ? Maybe they could evolve to be bigger and have teeth, they could eat all the other sperm before leaving the barrel, so ensuring they pass on their own genetic material, making a man with more monster sperm, eventually we will all have only on sperm, a huge ravenous beast with big pointy teeth.
then women would refuse to mate with us
and we'd die out
how ironic
There is a controversial theory that every man produces several different types of sperm. “Killer sperm” destroys the sperm of other men his mate has slept with. “Egg-getters” are the type that actually fertilizes the egg. The theory was developed by a biologist named Robin Baker, but I don’t think it is taken very seriously by other biologists.
Be watching some Hentai Tentacle movies?
I’ve heard that multiple sperm theory before. Some of the first ejaculate is supposed to be better swimmers, so i’ve heard from different sources, but that may just be because they get pushed out farther, or it might be an actual response to their being less man-fluid to help the sperm swim at that point.
I hadn’t heard of killer sperm before, I had however heard something similar, though more distateful. The pupose of a bell ended penis is to act as a kind of plunger to exctract other mens mess.
Hmmm, sounds doubtful to me. I’m more interested in a man’s sperm evolving in competition with his other sperm. It seems that if my sperm become gradually more agressive then the one T-REX sperm will get the egg because it’s damaged all the other sperm. My son will then, perhaps, have bigger badder ass sperm than me.
What’s interesting about this is that we have 2 diiferent types of evolution working against each other in the same organism, a man with only a few T-REX sperm will be less likely to sire than a man with lots of sleek fast sperm, but a T-REX sperm would be more likely to get the egg, if one were introduced.
You dig ?
This may only make sense if you’ve been up for 24 hours.
The problem with the “competing sperm” theory is that sperm tend to have a life span of only about five days. That, and they don’t themselves reproduce, so even if you did create a “killer sperm” through normal means, if you didn’t get any action during those five days, it would die off and you’d have to start over from scratch.
Complicating matters is the fact that the transition from spermatid (the cells produced by meiosis) to spermatozoa (the swimmy guys) – a process known as spermiogensis – is not well understood. The process also appears to occur without either any new gene expression or protein synthesis, since spermatids lack DNA replication “equipment”.
Of course sperm evolve, just like everyother phenotypic aspect of organisms. Some men will have better sperm than others (i.e., more competitive in a given environment), and will be more likely to have more children. These children will posses the genes for the better sperm, and the process will continue.
any “evolving” would have to occur in the testes not the sperm itself. It is like saying that a car is going to spontaneously redesign itself. It can’t. The MANUFACTURER [ie testes]is the only entity that could change the design
As far as I understand it, Robin Baker’s theories about sperm competition (which includes “blockers” as well as “killers”) rest on the premise that throughout human evolution, fertile females were very likely to be carrying around sperm from different men, as the result of having multiple sexual partners.
The evolutionary instinct, from the point of view of the male, is to impregnate as many women as possible, the resulting offspring preferably to be reared by their unsuspecting spouses. From the point of view of the female, the instinct is to become attached to a male who is able to provide a secure situation for her and her offspring but to secretly seek out the sperm of males with more attractive traits to father her children.
There is of course a competing instinct on the part of both males and females to create a stable family unit that will result in healthy offspring who survive to reproduce themselves.
I’ve read that the male dragonfly has a scoop on the end of his penis to remove the sperm from previous males. And in the one-upmanship game of evolution, this has led to the male staying in the saddle for as long as possible, to keep other males from scooping out his sperm, and that’s why you so often see dragonflies flying around attached to each other.
Well, scientists aren’t really sure as to the mechanism which cause the transformation from normal-looking cell to swimmy spermatazoa. The spermatid does not have the capability to “read” its own DNA, so the cause can’t be genetic in nature.
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Pretty much. Since the cornerstone of evolution is heritability, and there’s no way for a sperm to pass on any of its “traits” to another sperm, no within-sperm evolution is possible. As noted above, any changes in the sperm have to come from the source cells.
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Unusual, perhaps, but not unique. Red blood cells, for example, are pretty much the same way: they must be manufactured at the source (in mammals, they don’t even have nuclei), and eventually die off.
You gotta remember, those are weird little buggers. They only have HALF the number of chromosomes that a “regular” cell has. They don’t reproduce until after “the big moment” with the egg, and the two have merged genetic material.
~VOW
