Docta Jones! Docta Jones!
(Text from and photograph shot on assignment for, but not published in, "The Vimy Flies Again," May 1995, National Geographic magazine)
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Thinking of sand and blazing sun and bovid bones and a 40 page paper long since finished. Oi, Karen, five more months to go!
Man, I wonder what I’m going to know and think in six months. I live in terms of 3-month revolutions, and that encompasses two plus a whole new continent and a series of actions and responsibilities entirely new to me. I can’t wait.
But first: so much to do, starting with 40 pages on skeletal sexual dimorphism and the effect of sex hormones on bone development. Because I’ve pledged to cut out all my little witticisms and puns, I’ll dump them here instead. My mini-chapters could have boasted such titles as "Antler development: cancer and auto-amputation for fighting chance at sex" and "Horn development: The far side of the moon" and ""Do I make you horny, baby?": Evolution and diversity of ruminant cranial structures". I did however deem ‘boner’ too crass even for a tongue-in-cheek sub-title.
But get a load of this: "Sexual dimorphism in the mammalian skeleton: dissolving pelves, penis bones, and clitoral cartilage". No jokes there, swear. In mice, transplanted pelvic bones treated with hormones dissolved (!) while co-transplated ribs (for controls) did not. And an extra bit of bone or cartilage (or some combination of the two) down south of the equator is pretty standard across mammalia, though typically more developed in males than females. It’s actually a bit odd that human males (I don’t know if it extends to apes or primates) don’t develop this extra bone. And yes, it functions as imagined. I’ve seen it called a baculum (in dogs for sure), an os penis (in rats and in my textbook), or just penile bone. I’m not sure if the terms refer to the same thing, or if each names a variation in the structure of the bone. A lot of them are jointed, having a distal (end) addition of cartilage that may or may not ossify (turn to bone) as the animal matures. Function of a jointed baculum? I don’t know, but I’m guessing it reflects the fact that the need for such a bone, um, grows over time and reflects one or more challenges in copulation. Plus there’s always the question of birth. There’s at least one very good reason why bovids don’t have pointy little horns when they first glimpse sunshine. Dear lord, ouch. (Some do have developing horn buds, but they’re low and round). I’m surprised hooves have evolved more than once. There’s four of those on every horse! Eight on every artiodactyl!! (if you count the cloves separately).
Now, how is it that a blogpost initiated with the PG-rated idea of a Nazi-fighting man of history, science and adventure ends with a discussion of penis bones and the challenges of birth? Archaeology, paleontology, evolution, bones - at the end of the day, it’s all biology, right?
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Oh I could say so much right now! The 8th grade boy in me is really wanting to come out on this lil doozy.
Of course some religious types believe that the rib taken from Adam came from…well…from down yonder. I have my doubts.
Jointed baculum?!?!? Well I think that is just some in the animal kingdom showing off! Of course I don’t blame them. A jointed one might be fun to do, ya know, tricks with! But thats just me.
Comment by FIDO — December 1, 2006 @ 10:03 am