What is the difference between a megacolony and a species? If I replaced s/ant/mouse/ and s/megacolony/species/, would there be anything surprising about their results?
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."
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).
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!
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.
Generally speaking there is no altruism among members of a species unless they are very close genetic kin or at least part of a social group. You need to "expect" that the beneficiary of your altruism either has some of your genes, or will return the favor later.
By "expect", we don't mean conscious calculation, of course. Rather, we mean that the genes which favor this sort of behavior tend to be successful than genes that do not.
have you read the theory of the "baby face" phenotype being a ploy on this (and/or very similar) mechanism? I'll try and find the story I read.
I always found this type of analysis to be where genetics/sociology becomes most interesting
EDIT: although it's well off topic, sorry
EDIT': all I can find are the "babyface helps black CEOs" story... wasn't that one I read but it deals with similar findings
They're talking about if you took samples from colonies hundreds of kilometres apart, the ants would consider each other family and part of the same colony. This is astonishing, since usually ants fight anything that is hostile to their colony.
This story is really misleading. It's not a "megacolony" -- it's several distinct colonies from around the world that don't connect in any way.
The meat of the article is that researchers collected specimens from around the world, and some of the ants from different colonies didn't try to kill each other on sight.
Their point is the colony's are connected by people continously transporting ant's between each giant colony. So even if there is not a fixed land bridge there is continous mixing between the colony's.
What's even more interesting is people probably help to create and maintain the giant colony's in the same geographic area in the same way.
well, i believe they're using the term "megacolony" in reference to the fact that ants from different colonies are usually aggressive to ants from other colonies. but in this case, several giant colonies from different continents aren't aggressive towards one another and are genetically linked, so they're referring to the group of familial and non-aggressive colonies as a megacolony.
You sound unimpressed. But do you really feel you could take humans from all around the world and put them together without them trying to kill one another?
Yes. I lived in San Francisco for years. The murder rate there is about 7 per 100 000 population per year. Does that qualify as "not trying to kill one another" in your book?
Well, if the ants ever start causing significant damage to humans due to this genetic similarity (attacking crops or even, in a more sci-fi spirit, attacking people), shouldn't it also help eradicate them more efficiently due to them being one large monoculture?
I guess, but I would think that they would have to create a lot of damage to make it cost effective to engineer something that would hit them at the genetic level (taking advantage of their genetic similarity).
As per (http://news.ycombinator.com/item?id=684376), such large colonies are probably only maintainable with the help of humans (inadvertently transporting them around).
Even the large continental colonies probably need a certain amount of help with humans transporting new queens/males from one side of the colony to another side to help keep the genes similar. It's not like colonies that large only have a single queen. And with a large number of queens there is the possibility of genetic divergence from each other.
Unless the ants in those colonies have developed some sort of system themselves where they distribute new queens/males from one part of the colony to another... but I can't imagine that it would be easy for them to transport breeding ants (or for those ants to fly for that matter) 900km from one side of the colony to the other.
On the other hand, when it's time to mate, all the breeding/flying ants take to the sky. It's possible that each of the points of exit is close enough to other points of exit that somehow genetic 'stability' is maintained through this mingling. It just seems incredible that just random chance and proximity of flying/breeding ants to others with the beginnings of genetic divergence are able to keep genetic divergence in check to a degree that allows for these HUGE colonies to maintain close enough familial ties to cooperate.
Edit: Sorry, this just kind of turned into me rambling on with your post as a starting point.
From the guidelines (http://ycombinator.com/newsguidelines.html): "Off-Topic: Most stories about politics, or crime, or sports, unless they're evidence of some interesting new phenomenon."
From what I can tell, jokes are not tolerated here because they lower the signal-to-noise ratio. It's not that HN voters are humorless, it's just that they don't want HN to be a place people come for humor, because there's plenty of other spaces on the web for that. I'm starting to think of it as a college discussion group - you go to learn, not to hear Simpsons jokes.
Also the "overlords" joke has a long and tired memetic history in the hackersphere, which would explain the quantity of downvotes.
not all jokes are frowned on here. we just have very high standards. repeating a catch-phrase you heard somewhere else is never going to fly.
also, jokes are ranked differently. if you make a non-joke comment that is polite but not very interesting, its score will probably stay at 1. if you make a polite joke that isn't funny, it's probably going to get downmodded.
that might seem cruel, but i'd say it's necessary. a joke that falls flat tends to drag down the level of commentary.
I appreciate the explanations. I was not familiar with the fact that the "overlords" joke was overused in hacker circles, so I can see how it is played out. I'm just a big Simpsons fan.
