Seasons

That's the problem, they didn't. :\

It spontaneously arose from first principles. In another few billion years, it might constitute intelligent life.

So they're born with the ability to speak... Leedsish?

They're not born - there's no parthenogenesis involved. They divide by meiosis, and their language abilities have evolved out of a primitive proto-pheremonal chemographic communication system. It's fascinating really - like that vat of methane and carbon gunk at Princeton they've been zapping with x-rays and UV and electricity for 40 years now to recreate the preCambrian ooze, and which spontaneously forms amino acids and complex proteins out of simpler raw materials.

So, what I heard about coming from a cabbage patch is not true!

So is it developing life or is it just zapped goo?

Too early to tell. Ask me again in a couple of billion years.

So... they're a virus?

Well, there's no sign of a host, so more like bacteria or algae perhaps. There must be some sort of self-replication - perhaps RNA based. I'm not at all sure they've evolved to full DNA yet (see http://nobelprize.org/chemistry/articles/altman/)
It's how they use the phosphoester bonding to cleave to the TCP/IP stack to get online in the first place that puzzles me...

If you ask me, they all came from Mars millions of years ago when there was still water on that planet. They realized that, through cloning, their brain matter was slowly decaying, so they came to Earth to survive, and destroyed all evidence of their planet! Ha! I'm a genius!!!

Sounds like the plot from the game "Destroy All Humans!" to me... That game's fun!

Then again wasn't there evidence of bacterial life on mars?

Hmm, that might work. Except that I can see mars out of my study window even as we speak (well, type). But then again, there is an asteroid belt where the fifth planet ought to be. Do you suppose even Leeds organisms could be stupid enough to blow up the wrong planet?...