by Cheryl Rofer
I was delighted to see that the New York Times published an article today on some of my favorite animals, the bdelloid rotifers.
But no pictures! So I will correct that omission here.
I first met rotifers when I was in high school. I had a new microscope and needed something to do with it. I learned somewhere that if you put leaves in a jar of water and keep it warm for a few days, all sorts of fascinating microscopic animals and plants will develop. So I got leaves from a couple of places in the yard, put them in jars of water, put the jars on beams in our warm cellar, and there they were!
Little guys with mixmasters on their heads. There were others, too, with spiral stems, and lovely algae with boxy cells. But it was those little mixmaster guys that fascinated me. I drew pictures of them and submitted a notebook for extra credit in my biology course. I loved to irritate my biology teacher by calling attention to his incorrect Latin plurals, so I figured extra credit would put him in a position where it would be harder for him to cut my grade down for my being annoying.
But I couldn't find who those little mixmaster guys were for a few years. I loved it that their name was so similar to mine, while describing those mixmasters. I should explain that the mixmasters were actually two sets of cilia, which move in such a way to set up currents that draw still smaller animals into the rotifer's mouth.
Olivia Judson observes that the bdelloid rotifers, the kind I cultivated, have lived without sex for 85 million years. Instead, they appropriate pieces of other organisms' genome: bacteria, fungi, plants. It's turning out that it's easier for organisms to swap genes than we thought, and not only within their species or even kingdoms. Rotifers are animals, but they pick up genes from those three other kingdoms.
That kind of gene-swapping has been condemned by opponents of human manipulation of genes as unnatural. But rotifers do it. Bacteria do it. The fact that humans do it in a less random way does not make it wrong.
We need to be careful of what we're doing in genetic manipulation. But the rotifers tell us it's not unnatural.
I've included two photos of rotifers that look very much like the ones I became intrigued with. The first is from here, the second from here. As always, click on the photos for enlargements. That second link has lots more photos. Here are a few more.