> That's myth ( or we don't know for absolute certainty ).

I think there's a rather big difference between myths and things we don't know with absolute certainty. If you're open to the possibility that something is true, while knowing there isn't absolute certainty, calling it a myth seems misleading at best.

> If that was true, it would scoop your own semen out better than your competitors.

I haven't done a poll, but I suspect many males stop thrusting after orgasm. Assuming that is true then there isn't really any downside to scooping out your own old semen if you only do it in situations where you're just going to make a fresh deposit 30 seconds later.

> The shape has more to do with arousing females and making it easier for your sperm to reach the eggs than anything else.

I'd be interested in seeing the research supporting this idea. I'm not saying I think it's false, but I've heard the 'sperm-scooping' theory before, but never the 'arousing females' one.

> Monogamy or polygamy is a far better male competitive "design" than the shape of the human penis. The best way to ensure you impregnate a woman is through monogamy or polygamy rather than semen displacement.

By polygamy I think you specifically mean polygyny? Because polyandry sounds like the kind of situation where the sperm scooping would be pretty effective. And just because one mechanism to achieve something exists does not mean that other mechanisms are useful. The best way not to die of poison is simply not to consume poison, but I'm pretty happy the body is able to vomit if you (accidentally) consume poison anyway.

> The best time for a female to procreate is 19 to 26. It's their peak biological fertility years. When they're most fertile and when their children are least likely to suffer from defects. Starting from 30s, it gets harder for women to get pregnant, it's more dangerous for the mother and it's when poorer quality of offspring are born.

To quote your own article:

> Team member Dr David Dunson explained: 'Though we noted a decline in fertility in the late 20s, what we found was a decrease in the probability of becoming pregnant per menstrual cycle, not in the probability of eventually achieving a pregnancy.

So it sounds to me that although women in their late twenties are slightly less likely to get pregnant on any given menstrual cycle than women in their early twenties, the effect does not seem to significantly affect their odds of procreating.

> Starting from 30s, it gets harder for women to get pregnant, it's more dangerous for the mother and it's when poorer quality of offspring are born.

But since we're linking studies, I would like to refer to some research by the CDC [1] that shows that infant mortality is lowest for mothers between the ages of 30 and 34 (inclusive), and the infant mortality for mothers younger than 20 is the highest of all, significantly surpassing that of women over 40. Based on a report from Australia [2] which includes some information about the risk of mortality for the mother it also looks like having children before the age of 20 is inadvisable at best. Risk of death for the mother is lowest in the 20-24 range, but mysteriously the 25-29 range is at a higher risk of death than women in the 30-34 range.

Regardless, based on the data I don't think it's self-evident that the best time for women to procreate is between the ages of 19 and 26. I'll admit I haven't included numbers about birth defects. Another thing we haven't examined is the ability of the parents to raise and support their children. I suspect a 30 year old women may have the advantage over one 10 years her junior in that particular department. It is short-sighted to consider only biology when discussing the 'best' age to have children.

> A woman waiting til their 30s to have offspring is like an nba player waiting til they are 40 to join the NBA.

I don't think the numbers support that conclusion at all.

[1]: https://www.cdc.gov/nchs/data/nvsr/nvsr58/nvsr58_17.pdf (table 1, page 14)
[2]: https://www.aihw.gov.au/getmedia/a8ff4563-b8f6-43b4-826e-a86... (figure 3.1, page 22)