RIPLEY: How do we kill it, Ash? There’s gotta be a way of killing it – how, how do we do it?

ASH: You can’t.

PARKER: That’s bullshit!

ASH: You still don’t understand what you’re dealing with, do you? A perfect organism. Its structural perfection is matched only by its hostility.

LAMBERT: You admire it…

ASH: I admire its purity. A survivor. Unclouded by conscience, remorse, or delusions of morality.

* * *
Okay, this one is short.  In an interview, an evolutionary biologist explains why cats are, in an evolutionary sense, perfect.  There are big cats and little cats, but otherwise they vary surprisingly little in shape, diet and behavior.  They’re all doing one thing and they’re all doing it superbly well.

From a philosophical (or pedantic) point of view, she’s being a little provocative with that word “perfect”.  Is Patrick Mahomes a perfect quarterback?  Was Tom Baker the perfect Doctor?  Are McVities Digestive Biscuits (Milk Chocolate) the perfect snack with coffee?   No — those things are just the best in their respective categories.  

More seriously, when we’re talking about biology, perfection doesn’t exist.  Evolution is an endless game of King of the Hill.  You can stay on top for a very long time, but nothing is forever.  Theropod dinosaurs were the cats of their day, and they’re not around any more.  Cats aren’t really “perfect”.  What they are is excellent.

That said, three offhand thoughts.  One, cats are massively destructive to naive island ecosystems.  In New Zealand alone, they’ve caused the extinction of nearly a dozen bird species.  If you’re an island bird, then yeah, cats are almost exactly the xenomorph from the movie:  a relentless, intrusive, murderous alien whose structural perfection is matched only by its hostility.

Two, part of cats’ excellence is that they combine a very conservative design with a fair amount of behavioral flexibility.  Cats are the only hypercarnivore to establish a symbiotic relationship with humans, and that’s probably no accident.

And three, cats almost certainly shaped our evolutionary history.  Leopards, in particular, absolutely love eating primates, and there’s abundant evidence that they preyed upon our prehuman ancestors.  Superb night vision, ridiculously strong, ripping claws: they used to kill us with sickening ease.  Big cats, those perfect predators, were literally the monster in the dark. 

Some years back I visited a game park in Africa: lions, one elephant, a slinking thing in the distance that was a hyena.  And I remember thinking, dear Lord, imagine being out here at night, armed with nothing but a sharp rock or a pointed stick.  Out here with the big cats, who can see in the dark just fine.  It gave me the shivers to think about it, then.  It still does.

And that’s all.

 * * *

RIPLEY:  Final report of the commercial starship Nostromo, third officer reporting. The other members of the crew – Kane, Lambert, Parker, Brett, Ash, and Captain Dallas – are dead. Cargo and ship destroyed. I should reach the frontier in about six weeks. With a little luck, the network will pick me up. This is Ellen Ripley, last survivor of the Nostromo, signing off.

[to Jonesy the cat]

RIPLEY: Come on, cat.