Thursday, December 13, 2007

Two Research Papers, and things i've been thinking about lately

Here is a short excerpt from an article I read that covered a paper that was published in the journal Nature:

Japan Scientists Develop Fearless Mice

Associated Press Writer

TOKYO (AP) -- Cat and mouse may never be the same. Japanese scientists say they've used genetic engineering to create mice that show no fear of felines, a development that may shed new light on mammal behavior and the nature of fear itself.

Scientists at Tokyo University say they were able to successfully switch off a mouse's instinct to cower at the smell or presence of cats - showing that fear is genetically hardwired and not learned through experience, as commonly believed.
And here's an interesting video showing orca teamwork...the critical moment happens about 2:40 into the video, but the entire video is interesting. It appears as if the orcas are working in a team to push the ice floe (with helpless seal trapped aboard) into the water, and then they create a wave to wash their next meal into the water, where they will presumably chomp him (or her) to bits. More interesting is that (according to the researcher, who is filming) they seem to be teaching a younger orca about the hunting strategy...since its hard to tell from the video, I will take his word for it. (Thanks to Mo at Neurophilosophy for the reference to this).

The reference for the whale article:
Visser, I. N. et al. Mar. Mamm. Sci. doi: 10.1111/j.1748-7692.2007.00163.x (2007).

Some random, various thoughts that I have:

I'm a little troubled by the seemingly simple explanation that "fear is genetically hardwired and not learned through experience." Strictly speaking, I'd be willing to believe that the fear-of-cats response (in the mice) is brought about by the mouse genome, because of natural selection. Those mice with "the fear-of-cats gene" (remember that genes are not "for" something, but it makes it easier to speak as if they are) survived longer than those without the fear-of-cats gene, and they reproduced more successfully, and therefore the fear became "genetically hardwired." But then you have to think about gene expression, and you have to think about gene-environment interaction, and you have to think about the cats and their gene expression.

If mice were only found in the North American midwest, and cats were only native to Northeastern Africa, it is unlikely that mice would ever have developed a fear-of-cats gene, and it is equally unlikely that cats would have ever developed a mice-taste-good gene. In this way, it is only because of a sort of meta-experience that mice ever became afraid of cats, and similarly that cats favored the taste of mice. There was a very good reason that it was more adaptive for mice to fear cats, and similarly a good reason that cats came to enjoy mice. It was adaptive! I recommend the book The Selfish Gene, by Richard Dawkins for anyone interested in thinking about these sorts of things. (also, how convenient that the cats that the genetically altered mice were exposed to were docile house-trained cats, who did not need to eat mice to survive...)

Now this brings me to the question of the seals and the whales. Is anybody going to tell me, given this news about the mice, that the seal has not learned from experience (in the immediate, or meta- sense) that he is about to become dinner for those whales? Has not the seal watched countless friends and relatives suffer the same fate as he is about to suffer? And what about the whales? Even if it has become genetically "hardwired" to have a seals-taste-good gene, the young need to be TRAINED in how to get the seal in the first place. Not like visual edge detection in humans, which does not need to be learned. It is a learned behavior, like reading. There is variability in reading because it is learned. Some people are good at reading, some are less skilled. Some orcas are good at hunting, some are less skilled. In time, the good hunters' genes will be passed on, and the lesser hunters genes' will die out. Will some scientist in the future say that orcas are genetically hard-wired to make waves to push the seals off of the ice floe, because of the way that the environment interacts with the genes, today?

Maybe I'm just confusing myself...and whoever happens to read my ramblings.

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