A team of scientists from the U. S., China, and Finland has uncovered a fossilized woolly rhino in the western Himalayas of Tibet. This is hardly the first woolly rhino that scientists have unearthed (in fact indigenous people of Siberia have been digging them up for ages). What makes this particular specimen of the Cousin It of prehistoric mammals particularly significant is that it’s older than all the others.
Back in 2007, the team set out for the Zanda basin of the Himalayas because of the plethora of fossils it had yielded in the past. They found a complete skull and lower jaw of an ancient mammal that stood an estimated 6 feet tall and 12 to 14 feet long (so about the size of a Ford Explorer, but less fat). This animal had some pretty awesome horns – one on the tip of its schnauzer at 3 feet long, and another smaller one between the eyes. In other words, it’s pretty similar to the modern rhino….but with lotsa hair.
Originally, scientists thought that woolly rhinos appeared at the beginning of the Pliestocene era slash the last Ice Age slash about 2.6 million years ago. But, the Zanda fossils (termed Coelodonta thibetana sp.) are close to 3.7 million years old, which puts them in the Pliocene before the last Ice Age got started. Since they lived in the harsh environment of Tibetan mountains, these primitive woolly rhinos were preadapted with their shaggy dos to the cold and didn’t freeze their butts off when the world turned into an ice cube (slight exaggeration, I realize).
Male Flour Beetle: “Woman! Why are you hooking up with Jeff from the hardware store?… And Bob the Doctor?…and Ted the investment banker?”
Female Flour Beetle: “Sorry, Jerry, but you’re sperm’s just not genetically compatible.”
In the September 23rd issue of Science, researchers across the pond at the University of East Anglia found that inbred populations have a natural increase in female promiscuity to thank for preventing the harmful effects in offspring that come with getting it on with one’s cousin. Females actually take on more mates to screen out sperm from males that aren’t a good fit genetically.
For awhile, scientists have been wrestling with the evolutionary enigma of why some girls are so darn trampy. Although fairly rare in humans (to my knowledge?!), polyandry – where multiple males fertilize a female’s eggs – is commonplace for a wide variety of organisms from chimps to sea urchins. However, in a lot of these situations, things don’t turn out so great for the female. Hence, the enigma.
Using red flour beetles as their model species, the Brits set up inbred and non-inbred mating groups. They found that females who hooked up with just one partner only produced about half as many surviving offspring as those who mated with five males. The Brits double checked for male infertility, but found nothing. So, the only other explanation was that those guys just didn’t have the most “genetically compatible” sperm aka they were too closely related. The scientists then took it a step further and manipulated non-inbred populations to start inbreeding. Sure enough, after about 15 generations, the females started getting frisky and changed their mating patterns. They’re still working on how exactly the females weed out the bad sperm, but…
Moral of the story: Genetic diversity is super important, and a species will go to to great lengths to preserve it. And, don’t hook up with your cousin, even if you’re a beetle.
A group of physicians, virologists, and veterinarians at the Mayo Clinic and colaborators in Japan have taken what might seem like an unorthodox approach to fighting aids: genetically modified, glow-in-the-dark cats (!). Published in the most recent issue of Nature Methods, the study produced cats with intrinsic immunity to Feline AIDS, an epidemic among domestic cats, in hopes of using similar methods to fight the AIDS epidemic in humans.
They’re using what’s called a “genome based immunization strategy,” which is kind of like vaccinating your genome. Both humans and cats lack important proteins called restriction factors to fight HIV and FIV. So, the mayo team found a way to insert a gene from rhesus monkeys that produces immunodifficiency virus fighting restriction factors into a cat’s genome. Before the eggs were even fertilized, they shot them up with a gene eloquently named TRIMCyp. They tacked a jellyfish gene on, so that they would be able to see if the monkey gene was expressed. More specifically, they used the gene that codes for green fluorescent protein, which makes jellyfish glow underwater. (Part of me thinks that last bit was partially just for the awesomeness of making fluorescent cats, but I realize that scientists have been making stuff glow ever since they figured out what green fluorescent protein does.) The end result: cats that had the resistance gene, glow green under blue light.
LiveScience has an awesome photo gallery of adorable highlighter-colored cats.
The next step for the researchers will be to expose the kitties to FIV, and see if it works.