So I had read the news release, and thought "Ah! Finally, a chance to beat Myers to a post about cephalopods!" Silly me. You don't tug on Superman's cape; you don't spit into the wind; you don't pull the mask off the ol' Lone Ranger, and you never try to beat PZ Myers to a story involving cephalopods. But I do have a cooler illustration (which I will put at the bottom, just for suspense; the first illustration is the same one PZ used), again from Mike McRae. I was not planning to post it yet, but this story is just too perfect.
The first illustration, from Science magazine; on the left is a fossil ammonoid; on the right, the vampire squid Vampyroteuthis infernalis. The vampire squid lives in water with very little dissolved oxygen; the ability to live in such conditions may be the reason for an explosion of cephalopods following the Permian Extinction. For more information, see PZ's post, or the New York Times article, or even the Science article, if you have access.
The Permian Extinction wiped out ninety-plus percent
Of the creatures that had, by that time, evolved.
A rapid rise in atmospheric CO2 had meant
That the water had less oxygen dissolved.
(I know, I know, the animals on land were also hit,
But the news today is focused on the sea;
And you may call me biased—which I’ll readily admit—
So this story is more interesting to me!)
The ammonoids—the ancestors to octopus and squid,
And to cuttlefish (their greatest claim to fame)—
Were badly hurt, like all the rest; their population slid,
Ah, but from those few survivors, see what came!
The ammonoids exploded (metaphorically, of course),
Filling niches left by species that had died;
The few remaining species were selection’s vital source
For diversity to fill the planet wide.
Their secret to survival? One scenario is this:
They’d adapted to the cold, anoxic deep,
And the new conditions everywhere were like their old abyss,
So selection said: “I think, this one I’ll keep.”
When catastrophe sweeps multitudes from off the planet’s face,
Evolution makes the best of what’s still there;
This story shows that, sometimes, if you want to win the race,
Be a metabolic tortoise, not a hare!
Now, the beautiful illustration--a cephalopod version of Darwin's "Tree of Life"!