Thanks for the reply.

Biologists have DNA samples of every known species.

I do not believe that be true. Even if it is, a single sample is insufficient for a meaningful statistical analysis.

Ok, but how much value would it place on an organism which wasn't adapted to the modelers environment, as demonstrated by the fact that it was selected against and went extinct?

Non-negligible, depending on the criteria. It was my belief that human caused environmental destruction was the issue at hand. The organism was adapted for human's natural environment (most of Earth), the environment changed.

OK, but what reason, other than status quo bias, is there to prefer one result over the other?

The current environment supports human life. The recent bee scare was a multi-continent threat to a species very important to our way of life.

You probably mean price, not cost...

Pardon me, I thought I had changed that.

If something is useless, who cares how much supply of it there is, or how it's priced?

People who value money. Valdimir_M wrote: "If a particular species is useful for some concrete purpose, then someone with deep enough pockets can easily be found who will invest into breeding it for profit. If not, who cares?"

[Ethical arguments are] just begging the question.

I took the creation of Friendly AI to be an ethical consideration which was accepted by all commenters. I think the relationships are parallel.

I agree that non human sentient species deserve protection.... But what does that have to do with "biodiversity"?

I had in mind elephants, primates, and cetaceans. Each of these groups faces existential risks. Maintaining biodiversity is protecting species from extinction. Sentient species are a specific subset.

I was trying to argue for the propagation of the biodiversity meme. I felt that Vladimir_M was contradicting that meme. I thought I was being clear that my argument was not meant to be purely utilitarian (in which case I would have used values, or at least comparisons), but instead to argue that biodiversity has value within a variety of systems.