[ahayes]

Or, the obvious explanation being that all life that shares a common environment is going to have similar methods of existing within that environment.

That might be a plausible explanation except for the fact that studying multiple genes and constructing phylogenies provides repetitive evidence of gene relatedness. The evolution of genes can be traced by mutations, most of which don't have any effect on the function of the gene. Why should a Designer make multiple copies of the same gene in multiple species and then make pointless changes in them that suggest a line of descent? Then there are also pseudogenes, which have been deactivated by a mutation. The site of the deactivating mutation can be used to construct a phylogeny of animals sharing the pseudogene and can be used to determine when this branch split off from others that have the functional gene. Why would a Designer insert broken genes into a species? Then there are viral inserts that can also be used for phylogenies. Why would a Designer insert viral DNA in a pattern that indicates common descent?

I used to think the same thing, but I changed my mind.

[muawiyah]

Or, the entire body of genetic information available in every life form (including hundreds of millions of different viruses) is just part of a big ol' machine.

Hooking up different parts different ways gives you different critters. Maybe one of them is an intergalactic cruiser.

We have only started on figuring it all out.