Tuesday, May 15, 2007

Altruism in animals continued, BEES!


Comedian Eddie Izzard is the inspiration for the capitalization and exclamation point on BEES! I may have to do that this whole blog. The line is, "I like my coffee like I like my women... with BEES!" I love him, so weird.

So, bees and eusociality -- let the conversation begin.

Eusociality
is the ultimate evolved form of altruism, in a biological sense. For those who haven't hit the link, it's the kind of behavior we see in animals that live in colonies, that normally have sterile worker castes, and one or very few breeding "royalty." From a fitness standpoint, what the hell do the sterile workers gain from this scenario? It's obvious the Queen gets to spread her genes all over hell and gone, but the grunts got nothing going. Or at least that's how it appears. The workers are living a completely altruistic lifestyle.

The truth of the matter, now that the genetics of the situation have been sussed out, is that in all Eusocial animals the degree of relatedness is very very high. Meaning, most everyone you are surrounded by as a worker is related even closer to you than a human child would be toward it's parent (assuming no inbreeding).

Sometimes this high level of relatedness happens due to a genetic strategy called Haplodiploidy. In the case of BEES!, the males have 1/2 the genetic material than the females do. Without going into a huge explanation of it (Wiki does a pretty darned good job, so click that link if you are ravenous for more knowledge), it means that the sterile worker females are more related to each other than even to their queen. 3/4 of their genetics are shared -- humans have no analogy for this, except possibly that it's 1/2 way closer to being identical twins than being normal siblings.

As I mentioned before, relatedness in many situations determines the amount of altruism. If an animal helps their closely related kin, then their genes pass on and that type of behavior becomes prominent in that animals lineage. This is called Kin Selection. Like everything in nature, it's not *quite* that simple, but close enough. These bees are all having their genes passed on to the next generation quite efficiently by specializing at being good workers and not going through all the work and effort of breeding.

There are very few Eusocial animals in the world, most bees and wasps, some termites, ants, a couple beetles and one mammal. Only one mammal is currently known -- the Naked Mole Rat. These bizarre little buggers are not fashion plates, thus the picture of BEES! at the top of the page and not this.

They are also highly related, in fact even more than Haplodiploid colonial animals -- they are .81 or 81% related. How would mammals be this closely genetically similar? Inbreeding, intense inbreeding. Honestly, these are disgusting little animals. But, they are a God's-honest example of eusociality in Mammals, and the only one known of so far -- they deserve a mention.

Some time if I'm feeling scatological and sadistic, I may go into an explanation of these animals. But this morning, I have breakfast to eat and that wouldn't be conducive.

6 comments:

CtheG said...

I just got free tickets to see eddie izzard live tomorrow night. it will be the second time I've seen him close up in a small room where he does stand up. I ADORE him. He is so damn smart.

Bpaul said...

Holy hell I'm jealous. Let me know about the show plz. :-)

Trappin' Pat said...

The naked mole rats at the Portland Zoo are my favorite exibit.

Bpaul said...

That exhibit was difficult to build because the little buggers chew through concrete. Amazing.

I'll need to head down there now that I know more about em. Inbred backwoods little rodents.

goodRev said...

BEES! Good stuff. That naked mole rat could be THE poster child against inbreeding - "Your child, too, could look like a hairless coin purse!"

Bpaul said...

LOL!