P.Z. has his cephalopods, so, as an ailurophile, I’m gonna have my CATS! But with a dose of science. It is still a great mystery exactly how cats produce their purr. When I was younger I dreamed of solving this question and publishing a paper in Nature called simply “How cats purr.” But the experiments always involved a cat trained to purr on cue, coupled with some gruesome cutting experiments. Now it might be possible with MRIs—if they can be given to moving objects.
Um, hi. This is completely off-topic (let me first say that I wince at the thought of addressing a world-renowned scientist :-S) – but I was wondering if you could answer a little question that’s been nagging me while I was studying for Introduction to Botany (yes, this IS an undergrad biology student speaking).
Anyhow, if this isn’t your cup of tea (or field of expertise or otherwise) – let me just say: congratulations on the new blog! I’m totally buying your book (Why Evolution is True).
What is the question??????
Well, first of all, I’m an Israeli undergrad, so some terms might be lost in translation – but here goes:
We were told that grassy plants evolved from trees, and that this is a sign for regressive evolution – what I don’t understand is: how is that even possible? Trees are more elaborate, at least as far as the curriculum is concerned – maybe trees were more primitive to begin with?
Oh, and since I’m asking – I have yet another question, this time about the adaptive radiation in sea algae. We were taught that different sea levels contain different patterns of sea algae, usually correlating to the photosynthetic pigments each algae phylum has – I was wondering if there is anywhere this is actually demonstrated – and in particular, if a true “gradient” is displayed per depth? (I was kind of imagining algae “turning” from green to brown to red the deeper you go to the ocean).
Apart from the “how”, is it known *why* cats purr? Or is it just a side effect like snoring?
Frazer Sissom DE, Rice DA, Peters G. 1991. How cats purr. J Zool , Lond 223:67-78.
Since it’s caturday today..
What was god thinking when he designed this?
What about ultrasound? It’s much less sensitive to movement and it seems that with slight adaptations it would be perfect for pinpointing the source of the vibrations.
Our cat just past away from aggressive kidney cancer. When she was down to 9 pounds, the underside of her throat visibly vibrated (about 1/2 between jaw and sternum) when she purred. I could “feel” (by way of air) that the purrs were emanating close to the surface of her skin. My guess is that it’s coming from the base of the tongue, just above the larynx.
Now this is a blog after my own heart.
Of course – now someone is bound to draw fanart for PeeZed of an ickle kitten getting ripped to pieces by a pharyngalation of octopedestrians.