Spider Kama Sutra

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I’ve been savoring this lovely used book I picked up a little while ago, The Book of Spiders and Scorpions by Rod Preston-Mafham, and am appreciating more than the fact that it is full of beautiful photography of spiders and lots of general information on arachnid behavior and physiology; it’s also true that spiders are awfully sexy beasts. They are playful and romantic and kinky and enthusiastic and ferocious and savage and exotic, and really know how to have a good time. I thought I’d share a few of the pretty pictures and details of the arachnid sex life with the readers of Pharyngula—so if you’re mature enough to handle it, exuberant enough to enjoy reading about interesting animals doing fun things, and aren’t too squicked out at the idea of closeups of spider genitalia, read on.

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A squid too far

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People are so cruel. I was busy all evening with this talk (which went well, I think), and lots of people flood my mailbox with news of the giant squid at the NHM.

You know I can look out my window and see everything covered in over a foot of snow. You know I’m about as far from any sea as you can get. And you know you can get me pining for abyssal pelagia with this kind of thing—you all must love to torment me. Could you at least send tickets to London with this kind of news?

Oh, well. It is a thing of beauty at any rate, and I will just have to worship it from afar.

Lamprey skeletons

Bone is a sophisticated substance, much more than just a rock-like mineral in an interesting shape. It’s a living tissue, invested with cells dedicated to continually remodeling the mineral matrix. That matrix is also an intricate material, threaded with fibers of a protein, type II collagen, that give it a much greater toughness—it’s like fiberglass, a relatively brittle substance given resilience and strength with tough threads woven within it. Bone is also significantly linked to cartilage, both in development and evolution, with earlier forms having a cartilaginous skeleton that is replaced by bone. In us vertebrates, cartilage also contains threads of collagen running through it.

These three elements—collagen, cartilage, and bone—present an interesting evolutionary puzzle. Collagen is common to the matrices of both vertebrate cartilage and bone, yet the most primitive fishes, the jawless lampreys and hagfish, have been reported to lack that particular form of collagen, suggesting that the collagen fibers are a derived innovation in chordate history. New work, though, has shown that there’s a mistaken assumption in there: lampreys do have type II collagen! This discovery clarifies our understanding of the evolution of the chordate skeleton.

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Jurassic beaver

Say hello to Castorocauda lutrasimilis, a primitive mammalioform from the middle Jurassic—164 million years ago. Despite its great age, it has evidence of fur and guard hairs still preserved in the fossil, and was rather large for its time. It’s estimated to have weighed about 500g (about a pound) and was over 400mm (over a foot) long in life, and as you can see from the reconstruction, shows signs of being aquatic. In size and lifestyle, it probably resembled the modern platypus.

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Sensitivity, charm and cleverness: very sexy

Ah, the life of the female giant Australian cuttlefish…males fight for her affections, and during the mating season she will have sex with 2-8 different males each day, with an average total of 17 copulations per day. She can be picky, too, and rejects most of the mating attempts (yet still manages to mate up to 40 times a day). It must be a good life.

Males have a rougher time of it, I would think. There are many more males than females, and so it’s a struggle to get access to one; the bigger, stronger males will guard females, acting as a consort, and use aggressive displays to chase off competitors. What to do if you’re a smaller, but clever male?

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Chicken, archosaur…same difference

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My daughter is learning about evolution in high school right now, and the problem isn’t with the instructor, who is fine, but her peers, who complain that they don’t see the connections. She mentioned specifically yesterday that the teacher had shown a cladogram of the relationships between crocodilians, birds, and mammals, and that a number of students insisted that there was no similarity between a bird and an alligator.

I may have to send this news article to school with her: investigators have found that a mutation in chickens causes them to develop teeth—and the teeth resemble those of the common ancestor of alligators and chickens, an archosaur.

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