And this is old, old news

Feminists have debated it for decades, but scientists have finally got to the bottom of why men still exist.

Biologists have always puzzled over why males have survived given that their only contribution to reproduction is sperm.

It makes far more sense in evolutionary terms to have an all-female asexual population which creates daughters who can reproduce rather than sons who cannot, such as the Mexican whiptail lizard.

But new research suggests that sexual competition for mates keeps populations healthy, free of disease and genetically diverse.

“Almost all multicellular species on earth reproduce using sex, but its existence isn’t easy to explain because sex carries big burdens, the most obvious of which is that only half of your offspring – daughters – will actually produce offspring,” said lead researcher Prof Matt Gage, from the University of East Anglia School of Biological Sciences.

“Why should any species waste all that effort on sons? An all-female asexual population would be a far more effective route to reproduce greater numbers of offspring.

“Our research shows that competition among males for reproduction provides a really important benefit, because it improves the genetic health of populations.”

How many decades is it since Matt Ridley’s Red Queen?

15 comments on “And this is old, old news

  1. “Consider Her Ways” was by John Wyndham. “The Red Queen” was published two decades ago. I am pleased with myself for being able to answer both questions without resort to Google.

    As usual, don’t blame the researcher, blame the journalist. It’s clear from the story that all Prof. Gage and his Tribolium Flour Beetles are claiming to have done is confirmed theory by a ten-year experiment. A jolly good achievement for science, but not at all the same as showing it for the first time, as Sarah Knapton’s reporting suggests.

    I might stir myself to look up whether this experiment has settled which of the several potential advantages of sexual reproduction actually dominates, and whether it provides evidence of which of the several mechanisms by which sexual reproduction could have evolved (not the same thing as why it confers advantages now we have it) actually happened.

  2. … happened for the Flour Beetles anyway. Their evolution has clearly taken a very different turn to human evolution, resulting in such bizarre differences to humanity as exoskeletons, the ability to survive insane amounts of radiation, and responsible science journalism

  3. Biologists have always puzzled over why males have survived given that their only contribution to reproduction is sperm.

    Well, that’s a splendidly stupid question. The sexes evolved from a nonsexual ancestor, so actually the question is “why did males evolve?” not “why aren’t they dead yet.” Idiots.

  4. Ralph Musgrave – “My life has new meaning.”

    I try “hey baby, want to come back to my place and re-assort the DNA legacy of the human race in order to improve the genetic health of the species?” all the time.

    Meh. Some times it works, some times it doesn’t.

  5. It makes far more sense in evolutionary terms to have an all-female asexual population which creates daughters who can reproduce rather than sons who cannot, such as the Mexican whiptail lizard.

    I guess there’s a reason feminists don’t do much in science.

    Males exist because *sexual* reproduction spreads mutation around. Asexual reproduction produces clones – clones are a monoculture.

    It doesn’t do you a lot of good to be able to produce a lot of offspring if your environment has changed and your evolutionary niche is gone (or being filled by a more efficient organism).

  6. On the other hand, being able to produce a clone when you have the resources to reproduce and can’t find a male is quite a handy trick. Keeps your genes in the game.

  7. Agammamon writes, “Males exist because *sexual* reproduction spreads mutation around. Asexual reproduction produces clones – clones are a monoculture.”

    It’s true that sexual reproduction confers that benefit. However it doesn’t explain how it evolved in the first place. A mother reproducing asexually ensures that 100% of her genes appear in each of her clone daughters, as against 50% of her genes appearing in each of her children produced sexually. That’s a huge immediate advantage at gene level for asexual over sexual reproduction. In contrast, the benefits of sexual reproduction are diffused over the whole population and only show up in the long term. Great when you have them, sure, but it was difficult to see how sexual reproduction ever outcompeted asexuality in the first place.

    This question (how did sexuality evolve, given the path dependency problem?) did seriously bug evolutionary biologists for a long time. The answer that was eventually found is quite complex (translation: I’m wimping out of summarising it), and is what Matt Ridley’s book “The Red Queen”, mentioned by our host, and which it will be obvious I have just recently read, was all about.

  8. Men’s only contribution to reproduction is sperm? And femmis only contribution to anything is horseshit. How many women would survive to drop a litter never mind afterward if it wasn’t for the work men do.

  9. Natalie Solent – “A mother reproducing asexually ensures that 100% of her genes appear in each of her clone daughters, as against 50% of her genes appearing in each of her children produced sexually. That’s a huge immediate advantage at gene level for asexual over sexual reproduction.”

    Bananas are pretty much the same plant. The present Cavendish type is genetically identical to every other banana plant on the planet. We get all our main bananas from one genetic individual. All clones. Bananas are very sick. You cannot grow them in or even near their native environment of, presumably, Papua New Guinea – although the Philippinos insist on doing so. Wherever you do grow them, you have to drench them in chemicals around the year to make sure nothing gets a foothold. In fact in well organised countries, banana plants often have to be registered with the government so that if a fungal disease breaks out, the government can burn every plant within a 40 kilometre radius.

    The problem is that if a disease likes one plant, it likes them all. If the plant has no defense against a single fungus, none of them do. We have already had a mass extinction event when the previous banana species we liked, the Gros Michel, got hit with Panama Disease in the fifties and it was wiped out except for a few small places.

    Black Sigatoka threatens the Cavendish banana. It is likely that at some point it will spread so far that we will have to find another type. So enjoy them while you can.

    The point being having 100% identical children is great. Until a disease kills them all.

  10. SFMS – yes, the answer as Matt Ridley explained it was to do with parasites. I have found an essay by him which seems to be a quickie version of the first third of the book: Link.
    “Diseases specialize in breaking into cells, either to eat them, as fungi and bacteria do, or, like viruses, to subvert their genetic machinery for the purpose of making new viruses. To do that they use protein molecules that bind to other molecules on cell surfaces. The arms races between parasites and their hosts are all about these binding proteins. Parasites invent new keys; hosts change the locks. For if one lock is common in one generation, the key that fits it will spread like wildfire. So you can be sure that it is the very lock not to have a few generations later. According to the Red Queen hypothesis, sexual reproduction persists because it enables host species to evolve new genetic defenses against parasites that attempt to live off them.”

  11. Forgot to say, that the parasites thing can run in parallel with the purging of mutations as an effect of the fact that only the best males get to breed breed. Ridley seemed to think in 1994 that the parasites effect would generally dominate – apparently not so for flour beetles.

    Very interesting stuff about bananas. it’s disturbing to think that apparently secure elements of our daily life can just go, like elm trees did.

  12. The reason is that if you had one man to every hundred women, the male genes would have a hundred descendants to every one the female ones did. A mutation that led to more male children would result in more grandchildren.

    To be concrete – say each woman has two children and each man has two hundred, but 99% of births are female. Then your average number of grandchildren will be 98% x 2 + 2% x 200 = 0.01% x 400 = 4 grandchildren. A mutation that resulted in 2% male children would give 96% x 2 + 4% x 200 + 0.04% x 400 = 6 grandchildren, a massive advantage.

    A mutation that resulted in 50% male children would give an average number of grandchildren of 25% x 2 + 50% x 200 + 25% x 400 = 200 grandchildren on average!

    The more imbalanced the sexes, the more advantage the minority sex gets from boosting its probability. This forces the probability back towards 50%.

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