minor musings on the macrocosm
We saw plenty of bushtits, heard many more. But failed our primary objective: locating a nest. Blame multi-tasking. The dog had his own agenda, primarily involving ground-squirrels. And, I kept getting distracted by insects:
We did make some consolation discoveries at least. Apparently the university is developing a special breed of semi-log horse. Some limb-allometry project or something. At least that’s what I heard.
We also managed to see some Killdeer sex so, you know, net plus overall.
Barnacle (Chthamalus?) colony on Purple Shore Crab (Hemigrapsus nudus)
ADAPTIVE PLASTICITY OF THE PENIS IN A SIMULTANEOUS HERMAPHRODITE – J. Matthew Hoch, Evolution 2009
DOI: 10.1111/j.1558-5646.2009.00668.x
Abstract: Acorn barnacles are important model organisms for the study of sex allocation. They are sessile, nonselfing hermaphrodites that copulate with penises that have been suggested to be phenotypically plastic. On wave-exposed shores, Semibalanus balanoides develop penises with relatively greater diameter whereas in wave-protected sites they are thinner. A reciprocal transplant experiment between wave-exposed and protected sites tested whether these exposure-specific morphologies have adaptive value. Mating success was compared over a range of distances to compare the ability of barnacles to reach mates. Barnacles that grew in the wave-protected site and mated in the wave-protected site fertilized more broods at increasing distances than those transplanted to the wave-exposed site. For barnacles that developed in the wave-exposed site, there was no difference in the ability to fertilize neighbors between sites of differing exposure. This study demonstrates the adaptive value of plasticity in penis morphology. The results suggest a trade-off between development of a penis adapted to wave exposure and the ability to fertilize distant mates. Barnacles in different physical environments are limited by different factors, which may limit numbers of potential mates, constrain optimal sex allocation strategies and alter reproductive behavior.
Darwin would be doubly proud I think!
POSTSCRIPTO:
Sadly, I just noticed that Hoch buried the lead: a simultaneous hermaphrodite with a plastic penis that’s non-selfing!? What, do barnacles not have the internet or something?
Somewhere in Guizhou… check out the composite seed–there’s a trans-kingdom sex joke in there somewhere, but i’m too tired.
Alcids by Audubon from here. Crested Auklet is lower right.
While Secret Sex Lives estivates we’ll try to pick up some of the slack. Science Daily has a story on Crested Auklets (Aethia cristatella) that gives new meaning to the old pickup line “Hey baby is that aldehydes I smell or are you just happy to see me?”
Breeding pairs of these small seabirds smear a citrus-smelling secretion on each other as a part of their nuptial rites. Researchers have found that the compound contains chemicals with anti-parasite properties. According to Sibley’s Bird Life & Behavior the compound is so pungent that it can be smelled by birders on a boat some distance from the breeding colony.
Like many pelagic birds, alcids have elaborate mating behaviors, no doubt because breeding is a crowded affair with thousands of individuals converging on a few limited breeding sites. In such conditions it’s paramount to winnow the hunks from chaff relatively quickly. And, since any offspring are bound to have a rough life ahead out on the open ocean, getting some good genes for your babies is key.
Interestingly the elaborate sexual signals of alcids (e.g. the eponymous crest in A. cristatella, or the clownish beaks of their more familiar cousins the puffins) are seen in both sexes, in contrast to dimorphic sexual displays in many other species. I recently saw a talk by Kevin Padian discounting sexual selection as a good explanation for elaborate dinosaur structures since there is little evidence of sexual dimorphism in these creatures. The crests and tufts and whiskers and bills of Alcids, and their citrusey love juices, would seem non-dimorphic sexual selection in action.
[Note that the Audubon painting appears to show some dimorphism in the two individuals at left, IDed as male and female 'Ancient Murrelets' (Synthlibrorampus antiquus) but I'm pretty sure the brown one is a different species, maybe a Marbled Murrelet (Bracyramphus marmoratus).]
Male Convergent Ladybird Beetle (Hippodamia convergens) getting frisky with a mating pair of Asian/Harlequin Ladybirds (Harmonia axyridis).
I‘ve received my first online burn over in the comment stream at Laelaps. Well, if not the first, then certainly the most impassioned:
Neil,
I’m glad you wrote a letter. Good for you! You can write, but did you read anything I wrote? And? Just for the record, once again, I specifically said, at my blog, that I did not believe this particular revision in the evolutionary doctrine was going to prove anything for Christianity or Creation. Please, please I wish you all would stop suggesting that I said otherwise. I was perfectly content to post the article, make a comment or two, and let people draw their own conclusions until Brian linked back to my blog with his smart title, condescending remarks, and until many other started posting their ’science’ at my blog. But at my blog, I can defend it my way. I do wish you would stop mischaracterizing my blog entry.
Honestly, I am a bit confused that I provoked such a passionate responce since I hadn’t directly addressed either Jerry’s original blog post or his comments to Brian’s post. I had noted, by linking to Brian’s original post, that creationist bloggers had picked up the AP story about the Ileret skulls, in my post about the same. I also mentioned my exchange with the AP reporter in a comment which apparently inspired the portion of Jerry’s comment directed at me. Addressing the whole group of Laelaps readers Jerry goes on…
Thanks for all the fun. I leave you all with your rocks, bones, theories, charts, graphs, and unbelief. If I ever want to know about beetles (!) or water or trees or mars or ’science’, I’ll get back with you. If any of you ever need or want to know about Christ, well…you know where my blog is! Happy trails!
I guess that that too is meant as a burn, although I’m not sure what’s so uninteresting/irrelevant about water, trees or Mars (or bones and graphs for that matter). As far as beetles go, as J. B. S. Haldane observed, and Carel has recently reminded us (complete with his stunning beetle vanitas), a fondness for beetles would appear to put me in good company. I am glad that He cranked down the oxygen though, but more on that later.
Namaste!
Larval Asian/Harlequin Ladybirds (Harmonia axyridis) cannibalize a pupa of the same.
Hmm, perhaps they’re looking for something in which to enroll?
I thought, at first, that I might have this contest locked: fully most of my search traffic involves sex whether of the human, vampire, cartoon or even the seemingly oxymoronic ‘furry reptilian’ variety.
Which says something, about the internets or my weblog, or both.
But, in fact, Matt sets the bar quite high, I don’t think even my worst sicko reader can compete with “cats as sexual partners.” Well at least not this week….
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