Tag Archives: biomechanics

The Ant and the Elderly – a parable for an aging society?

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What a lovely story of an evolved society finding ways to integrate its elderly members into productive roles to keep the larger social unit functioning. Division of labor stratified by age/mandible sharpness – surely even we can learn something from that!

Zaphod Beeblebrox of Painted Turtles!

http://www.flickr.com/apps/slideshow/show.swf?v=71649

On our visit to Seattle last January, our friends took us to one of the odder “zoos” I’ve evervisited: the Reptileman’s Serpentarium and Reptile Zoo just outside Monroe, Washington. An odd “zoo” because it is housed in a commercial building more likely to be overlooked as just another pet store nestled in what looks like a little shopping strip along a highway! Among its impressively motley collection of snakes, turtles, lizards and crocodiles, housed in a variety of aquarium tanks, this little Painted Turtle caught my eye (and lens)- on account of its having two heads!

I’ve read about polycephaly (as this condition of having more than one head is known) occurring rarely in various animals, including humans, but had never actually encountered a real live animal with two heads before this little turtle! Polycephaly is a form of conjoined twinning, a developmental anomaly where the twin embryos’s bodies fail to separate resulting in the live birth of a multi-headed offspring. Not surprisingly, it is rare that an individual (or is it two?) survives such a massive developmental disruption to not only complete embryonic development, but go on to live a “normal” life. Yet, it is not unheard of – and in fact has been reported from a variety of animals as you can see in this list of recent occurrences under the wikipedia entry for Polycephaly.

I didn’t find out where this particular two-headed turtle came from or how it ended up at the Serpentarium, but it may well have come from captive-bred parents, because inbreeding can often lead to such developmental anomalies.

It is hard to imagine what life might be like if you had two heads – and two brains – controlling one body! How does this turtle decide which way to turn when moving, for example? Does one head come to have greater control over the body than the other? Do the brains get into conflicts? Apparently in snakes with two heads, one head has been known to actually devour the other – an interesting way to commit fratri/sui-cide! How does the evolutionary conflict of sibling rivalry play out in such creatures? Fascinating questions, but what a tough life, eh? No wonder then that not many such creatures survive in the wild.

And no wonder the notion of multi-headed creatures, with the inherent potential for fearsome awe and dramatic conflict, has caught our imagination often enough in our mythology, both ancient and modern!

So I couldn’t help it when this little two-headed turtle brought to mind the much more flamboyant Zaphod Beeblebrox from my favorite modern mythology!

 

Robert Full: Learning from the gecko’s tail

http://video.ted.com/assets/player/swf/EmbedPlayer.swf

And that is but a taste of what we will get this afternoon in our department colloquium here at Fresno State, for Dr. Full is on campus and will be speaking shortly. I will try to record audio for potential podcast.

Here’s the flyer for the event:

http://d1.scribdassets.com/ScribdViewer.swf?document_id=29678771&access_key=key-1i2lrhg83htexhe3k6uw&page=1&viewMode=list