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The ants in a megacolony are all genetically related, which is quite different from the way in which all members of a species are genetically related. Ants, al

The ants in a megacolony are all genetically related, which is quite different from the way in which all members of a species are genetically related. Ants, along with bees and a few other species have a haplodiploid sex determination system, unlike the XY system in mammals. This has a variety of consequences that are hard to swallow at first sight -- males have no father, all workers in a colony are clones, and so on. This is what leads to their highly social behavior within a colony: the good of one is the good of all. I don't yet understand how supercolony behavior arises out of ant genetics, but I'm sure it somehow does. It appears to me that this one of those evolutionary behaviors gone awry due to the rapidly changing environment. In the past, you could expect that ant colonies would migrate geographically at a fixed rate (on average); so with a constant mutation rate, you'd expect territoriality to arise from this behavior -- ants colonies in regions within (say) a 100- mile radius would be co-operative. Quite clever, actually. However, since humans are capable of transmitting the ants anywhere instantaneously (in evolutionary time), it has produced results that evolution didn't "intend." BTW here's the original paper http://www.springerlink.com/content/u081508512u7k421/ http://www.springerlink.com/content/u081508512u7k421/ More info. about the species in question: http://en.wikipedia.org/wiki/Linepithema_humile http://en.wikipedia.org/wiki/Linepithema_humile Also, http://en.wikipedia.org/wiki/Haplodiploid_sex-determination_system http://en.wikipedia.org/wiki/Haplodiploid_sex-determination_...

theblackbox 17y ago
I remember reading Mendel's Demon on the subject of sex differentiation as a means to prevent competition between mitochondrial DNA, and I wonder if there might be some interesting extensions beyond this that could be investigated using such "mega-colonies". I also wonder about the insights that could be gained into immune responses.... just makes me think there could be furious emergence at work here!
DavidSJ 17y ago
The workers are actually 3/4 related (assuming a monogomous queen), not clones of each other. This is because they all have the same genes from their father (since the father has just enough genes for one set of chromosomes), but only overlap on half of the genes they inherit from their mother (like mammals).
- randomwalker 17y ago
  Oops, you're right, sorry, forgot that workers are female.
scott_s 17y ago
But then how do we define species in non-XY sex systems? I know that in such a system, the simplest test is do members of the group procreate with one another. For example, there are two species of crickets that live amongst each other, are capable of producing viable offspring with each other, and behave identically except for the frequency of their mating calls. When we tweak the mating calls in a lab, we can get crickets from the different groups to mate. But since they don't mix in the wild, we call them two different species.

theblackbox 17y ago

I remember reading Mendel's Demon on the subject of sex differentiation as a means to prevent competition between mitochondrial DNA, and I wonder if there might be some interesting extensions beyond this that could be investigated using such "mega-colonies". I also wonder about the insights that could be gained into immune responses.... just makes me think there could be furious emergence at work here!

DavidSJ 17y ago

The workers are actually 3/4 related (assuming a monogomous queen), not clones of each other. This is because they all have the same genes from their father (since the father has just enough genes for one set of chromosomes), but only overlap on half of the genes they inherit from their mother (like mammals).

randomwalker 17y ago
Oops, you're right, sorry, forgot that workers are female.

scott_s 17y ago

But then how do we define species in non-XY sex systems? I know that in such a system, the simplest test is do members of the group procreate with one another. For example, there are two species of crickets that live amongst each other, are capable of producing viable offspring with each other, and behave identically except for the frequency of their mating calls. When we tweak the mating calls in a lab, we can get crickets from the different groups to mate. But since they don't mix in the wild, we call them two different species.