Marine Mammal Brains Are Full of Contaminants
From the Woods Hole Oceanographic Institution:
<<The most extensive study of pollutants in marine mammals' brains reveals that these animals are exposed to a hazardous cocktail of pesticides such as DDTs and PCBs, as well as emerging contaminants such as brominated flame retardants.
A Day in the Life of a Neanderthal
Please be sure to check out this week's Discovery News story concerning evidence that a modern human may have eaten a Neanderthal child.
Credit: Knut Finstermeier
I recently spoke with Gerrit Dusseldorp, an expert on Neanderthals and early humans who is at the University of the Witwatersrand's Institute for Human Evolution. Here's what he had to say about these puzzling hominids who may have been our relatives, our dinner or both. <<JV: Your research suggests that Neanderthals and hyenas occupied the same top carnivore place on the early European food chain. But didn't Neanderthals edge them out by being superior hunters? GD: First, hyenas, like Neanderthals were capturing very dangerous animals. However, it appears (from the few sites that I have looked at) that, if circumstances allow, hyenas prefer to focus on smaller game. In this case: At a French hyena den (called Lunel Viel) located in a forested environment, deer were the most common prey, followed at some distance by horse and aurochs. In a den (Camiac also in France) located in a Mammoth Steppe environment, bovids and horse are common, followed by woolly rhinoceros while cervids are rare. From extant spotted hyenas (of which we know that they are genetically indistinguishable from European cave hyenas) we know that they prefer to forage alone. When foraging in groups they are able to take much larger prey. However, since there is a strong dominance hierarchy, especially low-ranking animals may take part in hunting a large animal and not profit from the kill at all. It appears that in forested environments, where prey is dispersed, foraging alone is successful. On the mammoth steppe, prey is concentrated in large herds. Therefore foraging in groups becomes necessary and this leads to larger prey being represented at sites. Gentle Sharks & Murderous Cows
Mysteries have a way of balancing out. Today one mystery about the gentlest of sharks died and was promptly replaced by another about a near fatal attack by cows. The long-standing shark mystery, as reported in Discovery News, regards the secret migrations of basking sharks. Turns out they are pretty sensible and head to the tropics in the winter. But let me tell you something about basking sharks from personal experience. These are some curious animals. Although they are filter feeders -- eating whatever small stuff in the water they swim through -- they are still big; tens of feet long. What's more, when they have their gaping mouths shut, baskers bear an unnerving resemblance to their closest living shark relation: The Great White. This similarity struck home for me while I was in the water with some basking sharks off the Isle of Man about nine years ago. I was there for Discovery Channel providing a series of web postings about the gentle giants. The sharks I swam with were just babies, perhaps 12-feet-long. They were circling, getting a good look at the humans, when one of those humans (me) had a moment of trepidation: "Are you SURE these aren't Great Whites?," I asked myself. "They sure LOOK like Great Whites." Now about that cow attack mystery. Turns out it unfolded right there on the Isle of Man, wouldn't you know. Talk about synchronicity. Last Friday a bunch of perfectly healthy cows attacked a woman out for a walk, according to Manx Radio. The woman was hospitalized after the cows apparently used their bulky bodies to shove and crowd the woman away from their newborn calves. The woman reportedly thought she was going to die. She survived, thank goodness, but the same might not be said for her taste for veal. The mystery in this case is not, of course, that cows would defend their babes from what they perceived to be a threat. Oh no. That's just a basic animal instinct with a very good evolutionary explanation. What is really mysterious is that these cows, after untold generations and centuries of domestication and breeding, managed somehow to preserve enough sense to finally attack a human. That is mysterious and must be a little worrisome to cowboys and dairy farmers everywhere, don't you think?May 07, 2009
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