7 ms·
Interesting comment in the article's native discussion: > Chris Jankowski • 2 hours ago > The author says that sex "imposes a huge cost on a species, and tha
by forgotpwtomain 10y ago
Interesting comment in the article's native discussion:
> Chris Jankowski • 2 hours ago
> The author says that sex "imposes a huge cost on a species, and that cost is called “males.”"
Well, if the males are such a cost to a species, then why nature does not respond by heavily skewing the sex ratio of the offspring towards females. Males produce sperm which is cheap compared with the cost of producing eggs. A male could fertilize eggs of many - tens or hundreds of females. So the ratio could be 1 to 10 or even 1 to 100. But I do not know of a species that would do this.
> Some marsupials - possums and kangaroos create some skew, but is is slight and in response to environmental conditions or is more sequencing oriented depending on the age of the breeding female.
- mnw21cam 10y agoWhen male/female determination depends on which chromosome you inherit from a parent, it is hard for a mechanism to arise for the chance to be anything other than 50/50. A lot of mammal species eliminate excess males using other methods - mainly bloody fights to the death, which also tends to result in the remaining males being the strongest ones.
- Grishnakh 10y agoExcept that it's not 50/50, at least in the case of humans. With humans, it's about 1.07/1, in favor of males. The mechanism is much more complicated than a 50/50 chance of inheriting some chromosome.
- chongli 10y agoThe answer to the first question is Fisher's Principle [0]: Suppose male births are less common than female. A newborn male then has better mating prospects than a newborn female, and therefore can expect to have more offspring. Therefore parents genetically disposed to produce males tend to have more than average numbers of grandchildren born to them. Therefore the genes for male-producing tendencies spread, and male births become more common. As the 1:1 sex ratio is approached, the advantage associated with producing males dies away. The same reasoning holds if females are substituted for males throughout. Therefore 1:1 is the equilibrium ratio. [0] https://en.wikipedia.org/wiki/Fisher%27s_principle https://en.wikipedia.org/wiki/Fisher%27s_principle
- deleted 10y ago[deleted]
- forgotpwtomain 10y agoThanks, that's very interesting.
- mdrzn 10y agoThe only solution would be to ignore the 1:1 ratio and randomly kill some infant every once in a while to bring the ratio close to 2:1.
- grp 10y agoSorry? Can you go first? Please, show us the way!
- cousin_it 10y agoThat's not really an answer though. Females could choose to reproduce asexually. Even some large animals can still do it, like sharks. The mystery is why they don't do it all the time. What's the genetic benefit of making daughters that need males to reproduce, instead of making daughters that can clone themselves? Handwaving about "introducing variation via sex" doesn't help, because bacteria are the fastest evolving critters around and they reproduce asexually.
- chongli 10y agoBacteria reproduce asexually, yes, but they have developed an even more effective means of introducing variation than sex: horizontal gene transfer. That sex introduces lots of variation is undisputed, however, and the mechanism of sexual selection accelerates the process over that of the random drift in asexually reproducing species.
- soperj 10y agohorizontal gene transfer is basically what sex is, unless you do it standing up, then I guess it'd be vertical gene transfer.
- curun1r 10y agoIn many species, even though the ratio is mostly equal, most males don't reproduce. A single male becomes dominant and fathers most/all of the offspring. So it achieves the same effect as he's suggesting, a 1/n ratio of reproducing members of the species, but also adds test(s) to select out the weaker males. I believe this would be advantageous in species with longer gestational periods where you'd want to put as much of the fitness test up front and not wait until the babies are born to eliminate the weaker offspring.
- golemotron 10y agoBased on genome analysis, that's been true about human males also. http://www.denisdutton.com/baumeister.htm http://www.denisdutton.com/baumeister.htm
- reducesuffering 10y agoWhat an incredibly interesting analysis.
- golemotron 10y agoI reread that essay every year or two. It explains so much.
- deleted 10y ago[deleted]
- MrsPeaches 10y ago> Of the small minority of people who do like math, there are probably more men than women. Research by Jacquelynne Eccles has repeatedly concluded that the shortage of females in math and science reflects motivation more than ability. And by the same logic, I suspect most men could learn to change diapers and vacuum under the sofa perfectly well too, and if men don’t do those things, it’s because they don’t want to or don’t like to, not because they are constitutionally unable (much as they may occasionally pretend otherwise!). Its these kinds of lines that make it very hard to take this analysis seriously.
- simosx 10y agoThe first answer is that it appears there is no way for the embryo to have its sex selected non-randomly. It's like throwing a coin, you end up with 50% chances for each sex. The second answer is that there are indeed cases the environment can influence the chances for either male or female in several species. For example, mostly for reptiles, https://en.wikipedia.org/wiki/Temperature-dependent_sex_determination https://en.wikipedia.org/wiki/Temperature-dependent_sex_dete...
- jessriedel 10y ago> imposes a huge cost on a species, and that cost is called “males.” Incidentally, the cost of males is only a 50% overhead when the males contribute nothing to raising the offspring. In some species, the energetic/resource cost is dominated by caring/feeding/raising long after birth, which males may contribute to as much as females.
- brandmeyer 10y agoFor one thing, sexuality enables sexual dimorphism. We can compete and evolve as a symbiotic pair of subspecies with the advantages and disadvantages of both.