tdyo

Someone still has to build them. And buy them.

I suppose it's possible, but the fact that it is, in fact, DNA is enough to suggest it's from the last universal common ancestor (LUCA). If it shares the same ultra-conserved ribosomal etc sequences, then it's even more likely from LUCA.

This is exactly how they determine species distributions in ecology as well - http://en.wikipedia.org/wiki/Species_distribution

Uniform dispersion would suggest some territoriality aspect of the species, and clumped dispersion would suggest a heterogeneity of resources (or any other hypothesis that could then be tested).

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