Follow-up on the environment.... My fellow gnxp blogger Mary C has some questions about the environment. I'm going to respond here because she asks some good questions. First let me say though that I switched out of Biology to Chemistry to avoid taking any ecology courses-so I speak as a rank amateur (mighty rank at that!).

Regardless of species distinctions, Ehrlich is a straw man. If you want to have a rational discussion about the environment, it's best to exclude him altogether and substitute someone like E.O. Wilson, who generally seems to please the folks in this group with his other views (sociobiology, natch), but due to the fact that his love and livelihood is animals, is a species conservationist as well. Ehrlich's love and livelihood, on the other hand, is worrymongering.

Well, I think Ehrlich's books were more accessible to kids back in the 80s than any of E.O. Wilson's stuff. I think that Ehrlich is easy to pick on compared to a more measured scientist like Wilson (though Ehrlich is a population geneticist-he's no un-lettered yokel obviously like some of the eco-radicals), but he is the public face of the "population crisis" (and the environmental crisis secondarily whenever you read his books) for young lay persons interested in the situation. Wilson's books tend to be more philosophical and cerebral, and don't have (in my opinion looking back as a scientifically curious 8 year old) slam-bam appeal of something titled The Population Bomb. Onto your points about overfishing and biodiversity. I keep trying to get my friends that are doing graduate work in Ecology to read to The Skeptical Environmentalist to pick out the possible flaws, but until then, all I can say is that though a lot of Bjorn's stuff on mineral resources blows me away, his work on biodiversity (and to some extent the greenhouse effect and global warming) leaves me a bit less sure. I do think that Bjorn has put the onus on ecologists to justify their positions on extinction rates more quantitatively (in fact Bjorn sets his sights on the Wilson's position that fragmentation leads to extinction rates with the Atlantic Brazilian rainforest as a situation where this hasn't occurred). [see Bjorn's site and that of the anti-Lomborg pie-thrower] The thing about "big cuddly animals" though is that a lot of environmentalists will argue that if you can save them in their natural state-you're saving a lot of smaller animals. The big cuddlies tend to need a lot of space-and so a lot of habitat. Of course, they know that it appeals to the public more. I'm not a at-all-costs libertarian anymore either-so I would concede that fishing is basically hunting on an industrial scale and so there are valid issues with sustainability. I do look to aquaculture as a long term solution. The problem with the ocean is that it is a classic tragedy of the commons-a lot of countries have problems with poaching on their coastal waters (the Japanese are big culprits from what I've read). I don't think overfishing is going to disappear as a problem until aquaculture makes it economically unviable.