I just gave my talk at TAM on likely paths of alien evolution (my conclusion: humanoids are extraordinarily unlikely), and there was one awkward bit I have to fix.

Here’s the problem: these were short talks, only a half hour long, so I designed it so there were some optional bits I’d only get to if time allowed, and I also had a couple of places where I could naturally bring it to a close if I ran over time. I was not able to show the last two slides I’d prepared, which was OK, I was ready for that. However, when we were setting up, the technician accidentally flashed the very last slide to the audience, which is a weird image, and it had to be left unexplained…so now I’ll explain it here on the blog.

Here it is, PZ’s TAM talk: the Lost Slides. This was to go right after I’d summed up the main reasons why we ought to expect great surprises in any alien morphology.

There’s one more brief and somewhat tangential point I have to make, because it’s weird and keeps coming up. I call it the Kirk effect: to boldly go and explore strange new worlds, and to hump all the women on them. This is not going to happen.

This is the most recent outrageous example of this, from the space fantasy movie Avatar. James Cameron consciously chose (for understandable dramatic and profit-making reasons) to completely ignore what science said and shape his aliens to fit human expectations. And that meant making them sexy.

This is more than just sticking large lumps of adipose tissue on the female’s chest. It’s deep and subtle changes to the shape of the face, the eyes, the whole of the body — cues that we all unconsciously recognize. You don’t even need to see a person face-on to recognize sex. All you heterosexual men and lesbians, you know this: sight of the nape of the neck, the curve of waist to hip, all those are enough to make your heart go pitta-pat. And all you heterosexual women and gay men: broad shoulders, narrow hips, muscular buns…they can do it for you, right?

Let me show you. I know this is a family audience, so if you’re shy about female nudity or assertive sexual displays, I’m going to show you a bit of porn to make my point. So if you’re a little prudish, put your hands over your kids eyes or your own, because this may be an arousing image…

If you’re a chimpanzee. That’s an image rich in sexual cues for a chimp: the posture, the sleek hairy body, the genitalia greatly swollen by estrus into a bright pink lump. If there were a chimpanzee Hugh Hefner, he’d be printing stacks of magazines full of glossy photos just like this one.

Now I know there’s always one in a large crowd — rule 34 and all that — but I can pretty much guarantee that almost all of you here find that completely lacking in all of the sexual cues that might stimulate you, and the majority probably find it entirely repellent, it’s so far from our species-specific norm of sexual attraction. And this is our closest living relative!

So one last word of advice: if you’ve been swayed by all the romantic imagery of the science-fiction media that suggest alien planets are full of intelligent alien babes of exotic beauty, forget it. Space travel won’t get you laid.

That’s it, that’s all you missed. I know some people were a bit bothered because they saw a bit of the punchline but completely missed the setup.