The evolution of expendability: Why some ants traded armor for numbers

Ants with lots of workers tend to put less energy into making them armored.

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[Chuckstar]

Worker bees are in fact half-sisters, their mother is the Queen bee who mated with 10-20 drones before retreating into the hive to lay eggs for the rest of her live (or until she leaves the hive with about half the swarm to settle somewhere less busy). One of the remaining fertilized eggs can then become a new queen (Unfertilized eggs become drones). So in the end not so much cloning but regular genetics, just with an unusual number of sisters... The general idea of shared genetics within a colony is correct though.

Not all workers are half sisters. If the queen successfully mates with 10 drones, then there will be ten sets within which all are of full sisters, while being half-sisters to the workers in the other sets.

And it isn’t quite “regular” genetics between the full sisters. Males are haploid, so full sisters average 75% of the same genetics, instead of the “regular” 50%.

 

[Chuckstar]

So, the termites are not closely related to the ants (although the ants are fairly closely related to the wasps and bees); turns out termites are basically cockroaches (which I learned about 90 seconds ago*). I wonder if someone will apply this sort of analysis to the termites and see how well it fits with them as well?

*I mean, I knew the termites aren't closely related to the ants; I didn't know they are closely related to the cockroaches. Gives a whole new wrinkle to the old "the cockroaches will be the only things to survive World War III and will inherit the Earth" meme. And then, they will build mighty cities, and great plantations of fungi, and so forth!

Bees, wasps and ants are more closely related than they are to termites, but I would point out for clarification that near as we can tell eusociality evolved separately in all four lineages.

The current best understanding is that wasps, bees and ants diverged somewhat over a hundred million years ago, with bees evolving from wasps that started eating flower pollen (flowers being relatively new at the time) and ants evolving from wasps that became ground predators. Evidence of separate evolution of eusociality includes facts such as genetic studies showing that ants are more closely related to non-social wasps than social wasps as well as lack of fossil evidence of colonies/hives in any of the lineages during the early eras after they split.

And just to fill out the data, beetles and wasps diverged more like three hundred million years ago.

 

[Chuckstar]

No, it would require significant changes to human reproduction. Reproductive medicine is already a politically charged topic, I just can't see it happening*.

There are practical implications as well: I'm not sure that you can get there from an XY sex system. XX individuals who self-fertilize can only have daughters, but eusociality generally requires haploid males. Leaving aside the question of whether haploid vertebrates are even viable, you'd at least have to start with a sex system with WZ females and WW males. These animals exist, and some snakes have been documented to give birth without ever mating, but only to diploid WZ and WW snakes.

And that haplo-diplo lifestyle is also a major change, plants go through this which is why they produce pollen, tiny spores capable of hatching and growing short-lived male gametophytes, like if one's testes produced little mini-testes instead of sperm. So yeah, once you start borrowing plant-style haplo-diplo life cycles, you're pretty far removed from mammalian biology.


*It has been tried in the past with castrated slaves, but that's a bit drastic and also not an evolutionary procedure

This isn’t at all true. Naked mole rats are fully diploid. The worker caste is made up of males and females who are reproductivity suppressed hormonally. Haploid/diploid is just how some eusocial reproduction works. Haploid males are not “required”, by any means.

EDIT: Oh, termites and eusocial shrimps are also diploid. Really only the eusocial hymenopterans use the haploid sex determination system.