TGIF

All the extracurriculars are taken care of for a while. A long but fruitful week, with a few very strange punctuations. Topped off with a student production of Twelfth Night. Well done, guys.

Night music...

Do you want to live forever?

One of my students pointed out this story on Turritopsis nutricula, a hydrozoan (Phylum Cnidaria) which can revert to the polyp stage from the adult medusa form. The process can apparently be repeated over and over again, making T. nutricula, for all intents and purposes, immortal. As you might imagine, this abilty had made them the subject of serious interest on those biologists interested in slowing or reversing the process of development and aging.

Actually, the process is poorly understood. Laboratory studies have shown that all stages of the medusa can revert to the polyp form. The process, however, takes place very rapidly and has never been observed in nature. Truth is, the prospects of immortality for an individual are pretty low, given that they experience high rates of predation. Still, the ability to start over at any point is a pretty effective tool to have in one's life history toolbox.

That's the good news. The bad news is that this unique ability, coupled with the anthropogenic contribution of spreading the little guys across the globe through ballast water, has turned T. nutricula into a serious invader around the world ocean.

Thanks, Chris.

Black hats

ScientificAmerican.com has an interesting esssay by paleontologist Scott Sampson, who points out that we should probably laud the incredible success of dinosaurs rather than dwelling on their ultimate extinction. They represented the dominant form of life on the planet for about 160 million years, a couple of orders of magnitude up on us. And, of course, they didn't really go away. Just look out the window and you'll likely spot a couple of little flying dinos.

Sampson also points out that, while extinction is the inevitable fate for any species, unnecessary and untimely extinctions are probably a bad thing. So, the fact that the the driving force behind the sixth of the great extinctions is not an asteroid or Milankovitch cycles or a virus, but a certian bipedal primate should motivate us to reverse the process. When future historians of another species look back at the history of the planet, do we want to be discussed under the section titled "The Hitler Species?"

So, maybe you CAN go home again...

You, and your ancestors, have spent thousands of years adapting to the eternal darkness of caves buried as much as a kilometer below the surface of the earth. You've lost your eyes. You've lost your pigmentation. You're all in for the stgyian blackness. Then, the rules are changed. You find yourselves closer to the surface. It's warmer. The darkness turns to light. But, is it too late? Are you locked in to your subterranean lifestyle?

Research with cave-dwelling scorpions suggests that you can get your evolutionary money back. The scorpion Family Typhlochachtidae includes a number of species found in Mexican caves. Although all show adaptations for life in caves, several live closer to the surface and show a more generic body form than those found at greater depths. In work led by Lorenzo Prendini of the American Museum of Natural History and to be published in Cladistics, researchers developed a phylogeny based on 195 morphological characters and discovered that three shallow-living, morphologically unspecialized species are descended from specialized deep-dwelling species. This runs counter to the predictions of "Dollo's Law", which suggests that selection leading to the develoment of highly specialized traits is not reversible.

Prendini suggests that the evolutionary flexibility of scorpions may play a role - they are, after all, among the oldest extant invertebrate groups. On a more speculative note, he also suggests that the "new" surface dwellers may have been able to come up out of the dark when the Chicxuluxb asteroid wiped out the competition some 65 million years ago.

Detective work

I'm frequently astonished at the amount of detail that paleontologists can glean from fossilized remains. Quite honestly, it's easy to understand why the uninitiated often view their conclusions with a degree of of skepticism.

That said, take a look at this. An Italian team of paleontologists have taken a close look at the fossilized remains of 4 million year old dolphin, and concluded that it was killed by a 12 foot long shark known as Cosmopolitodus hastalis, which attacked it from below, biting deep into its abdomen. The shark then shook its head violently, tearing out large chunks of flesh and causing great loss of blood. Then, when the dolphin rolled onto its back, the shark administered the coup de grace with another bite in the region of the dorsal fin.

Giovanni Bianucci, who led the study (and produced the illustration above), says the 8 foot long dolphin, of a species known as Astadelphis gastaldii, had lain in a museum in Torino, Italy for over a century before he began to work with it and noticed the distinctive bite marks.

CSI afficianados should take heed. You think a cold case is a challenge? Here's the actual work in Paleontolology.

OK, let's talk about this...

Capuchin monkeys, when presented a choice between their favorite food and a variety of foods, choose variety. Question - how general is this, and what's the evolutionary significance of it? Is it simply the result of selection for a diverse diet to include essential nutrients, or does it go deeper than that?

Dancer's Middle Eastern ancestry

Small dogs, it appears, share a variant of the gene IGF1. A group of researchers led by UCLA's Melissa Gray and Robert Wayne surveyed grey wolf populations and concluded that small dogs probably originated there. Remains of small dogs have been discovered in Middle Eastern archaeological sites dating back some 12,000 years.

Hydra genes

Still another example of what will be the story of the 21st Century - the explosion of genetic revelations. A group at UC Irvine has completed the sequencing of of the genome of Hydra, a freshwater cnidarian polyp well known to zoology students everywhere. They reveal a genome about the same size as that of humans, and sharing many of the same genes. Particularly interesting are genes that, in humans, may play a role in Huntington's disease and Alzheimer's. This makes Hydra a prime candidate for research into those disorders.

The paper appears in Nature, or you can read the summary at Science Daily.

Fedexia

My vert zoo guys and I were talking the other day about the significance of certain regions when it comes to looking for certain types of fossils. I saw Neil Shubin last year, and he discussed the importance of knowing where to look - where to find exposed rocks of the right type and the right age. China for early birds, the Sahara for crocodilians, western U.S. for tyrannosaurs - the list goes on. There are several key sites for the early amphibians. Shubin found Tiktaalik in the Canadian Arctic, but he and other specialists on that period have focused heavily on western Pennsylvania.

A new report appearing in the Annals of Carnegie Museum describes a new species, found in 2004 near the Pittsburgh International Airport. It's named Fedexia streigeli, in recognition of the fact that the site where it was found is owned by the FedEx corporation. The rocks in which F. streigeli was found are from the Pennsylvanian Period, about 300 million years old. This is important, in that it pushes even further back the time at which terrestrial amphibians can be documented.

The roughly three-foot long Fedexia belonged to a group of amphibians known as the Trematopidae, unique in that they were adapted for a largely terrestrial existence and perhaps returned to the water only to lay their eggs. As such, this was likely the first North American vertebrate group to tackle the terrestrial lifestyle.

Read more here at Science Daily.

Con Bio

My conservation biology guys and I will be discussing this topic later, but this is an interesting illustration of a key concept. Work examining extinction patterns for a number of large mammals in India has discovered that the current state of protected areas in the nation will not allow many of the species to survive the 21st Century. The study, appearing online in the British journal Proceedings of the Royal Society B and summarized here at Science Daily, attempted to determine the probability of extinction for 25 species, some of them on the IUCN Red List of Threatened Species. d extinction probabilities for a range of species. It looked at species considered endangered or critically endangered on the 2009 International Union for Conservation of Nature (IUCN) Red List of Threatened Species and some of them species of least concern.

The group drew on a large database to examine the effect of a range of factors on extinction probabilities. They found that protected areas were among the most significant factors lowering extinction risk, along with greater proportions of forest cover. Human population density was a key factor associated with increased extinction risk. Particularly interesting, though perhaps not surprising, is that our perception of a species has a lot to do with its probability of making it or not. Species that are perceived as non-threatening have a better chance.

Speaks well for our chances of saving the cute guys. But what about tigers?

For the birds

Of course, any Fox-watcher knows that the whole climate change thing is just another hoax enacted on an unsuspecting public by us scientific types. But, if you're interested... a new report documents the impacts that coming climate changes will have on the nation's bird populations. The study, a collaboration between a number of state and federal agencies, along with organizations like the Cornell Lab of Ornithology and the National Audubon Society stresses that climate change will have "an increasingly disruptive effect on bird species in all habitats." You can see the report here in its entirety, or read ScientificAmerican.com's summary.

Particularly impacted will be seabirds, island-dwellers, and birds dependent on coastal habitats. Warming climates will also reduce available habitat for artic and alpine species such as ptarmigan. No habitats, however, will be unaffected.

Secretary of the Interior Ken Salazar, announcing the report, recalls Rachel Carson in pointing out that "our migratory birds are sending us a message about the health of our planet."

Maybe we should let the whales eat him

The majestic animal at right is a sei whale, Balaenoptera borealis. The sei reaches lengths of 50-60', and has been listed as endangered since 1980. There are, perhaps, 50,000 sei whales remaining, maybe 20% of their population size prior to whaling. Apparently, the considerably less majestic animal on the plate at right is a sei whale, as well.

The owners of a Santa Monica, California restaurant known as The Hump were charged last week with serving whale meat. Also charged was Kiyoshiro Yamamoto, sushi chef at the restaurant. He apparently served whale meat to two undercover informants during a sting operation. The Marine Mammal Protection Act, passed in 1972, prohibits the sale of whale meat of any kind.

Here's the web page for The Hump, with the requisite apology for their actions. Far too little, far too late. But that's just my opinion. Well, maybe not.