Night music, old school

Fought the fight on this one, and my better self won out.

If you see her, say hello.

Doing it for the kids

It's proven tough for Tigers, but frogs can do it. A group of biologists have identified the first example of a monogamous amphibian. It's Peru's Ranitomeya imitator, the mimic poison frog, and the investigation seems to tell us something about the evolution of monogamy. A comparison of R. imitator to the closely related variable poison frog, R. variabilis, yields some interesting results. Both utilize small pools for breeding, but the breeding pools differ in size and in the availability of nutrients. Mimic tadpoles mature in tiny, nutrient-poor pools formed in the folds of leaves. They're carried there by the male parent, and fed in the days afterward when the male calls his mate to lay unfertilized eggs in the pool. These eggs provide nutrition for the little ones. Tadpoles of the variable poison frog, on the other hand, grow up in larger pools, tended primarily by the male parent.

The researchers suggest that frogs using the larger breeding pools can go it alone in bring up Junior. The guys in the tiny leaf fold pools, however, are stuck with each other. For the kids sake.

I'm sure there are all sorts of conclusions, both biological and sociological, that can be drawn from this work. Truth is, though, I'm just too tired to think about it right now. Maybe later.

Jurassic Peck?

Yeah, I know. But it's late, OK...

This intrigues me. Scientists have found a way to isolate DNA from fossilized egg shells. Fossil egg shells are pretty common finds in deposits around the world, and have been extensively used for analyses like radiocarbon dating. Now, researchers may also be able to use them to create a DNA profile of extinct species.

One of the birds that's being examined is the the elephant bird, Aepyornis. The name is descriptive - Aepyornis was the largest bird that ever lived, reaching heights of 10 feet and weighing nearly a ton. They're looking at eggshells of another extinct giant, the moa, as well.

I know what you're thinking... I don't know the answer for certain, but I strongly suspect it's "No, we won't be able recreate elephant birds and moas." Fun to think about, though.

Washed out

Sucarnochee crested about 6" south of flood stage earlier this week, but may go back up with additional rainfall tonight. Flash flood watch in effect until 6 in the morning, and tornado watch in effect until 2. All of our sites are washed out for at least the next week - our groups have virtually no usable data.

Sometimes I wish I was a gene jock.

Some quick hits

Long day today, that just concluded an hour ago with a roundtable discussion in my seminar class. Just time for a couple of short notes...

Earlier this week, a colleague and I took advantage of an unexpected holiday to drop a canoe in the river. As we were walking out, we noticed a dramatic difference in our relative appeal to the Sucarnochee mosquitoes. I was ignored, he was the buffet. No surprise there - there's been a lot of work looking at the variety of cues that mosquitoes use to zero in on their next meal. Carbon dioxide, lactic acid, and an organic chemical known as octenol have all been implicated. Well, a new study in PLoS One takes a closer look at the process. Octenol forms enatiomers - sterioisomers that are mirror images of each other. Enatiomers can have different properties, and octenol is no exception. The PLoS study, performed by Jonathan Bohbot and Joseph Dickens from the Department of Agriculture, uses manipulated frog eggs to mimic the manner in which the mosquitoes would respond to the right-handed and left-handed enatiomers of octenol. That's the right-handed version to the right. They found that the right-handed form elicited a greater response than it's left-handed isomer. This is the first demonstration of the ability to detect "handedness" in insects, and should lead to a better understanding of how to ward off the little guys. Given the potpourri of disease organisms they carry, that's nothing but good news.


Interesting work at the boundary of biology and physics. Researchers looking at the manner in which loggerhead sea turtle hatchlings manouver their way through the sand on their way to the sea find that the little guys are able to adapt the manner in which they use their flippers to move easily across different types of surfaces. Next step - robotics.

Fish story

Sticklebacks are cool. They demonstrate some extremely interesting behavior (more on that later) and have been the subject of some very significant research in ecology and evolution for decades. The threespine stickleback (Gasterosteus aculeatus) is essentially a marine fish, but many populations have been able to adapt to freshwater conditions. In Alaska, where populations have been landlocked by receding glaciers, they've evolved rapidly to adapt to their new environment. Changes in body armor, coloration, and behavior distinguish different populations. A new study appearing in PLoS Genetics attempts to get at the genetic basis of this adaptive process. Researchers compared genomes of five populations of sticklebacks, three from landlocked freshwater populations in coastal Alaska and two from nearby marine environments. The fish turned out to be very similar across most of their genomes, but proved to quite different in certain areas. What is particularly interesting is that the landlocked populations, independently derived, showed similar changes. This suggests that different populations are using the same genetic toolbox to solve the problems posed by their new freshwater habitats. The effort now is to identify the specific genes involved.

Ancient crocs...

My vertebrate zoo group and I talked the other day about some of the early crocodilians like Purussasaurus and Sarcosuchus. Thought it might be a fruitful area for some YouTube surfing, and indeed it was.



The National Geographic video is dramatic enough, but it's a little speculative and doesn't provide much in the way of biological background. There's a little more of that available here.

I saw a lecture by Paul Sereno a few years ago prior to one of his African expeditions, not long before his Science paper on Sarcosuchus. The Sahara has proven to be a very fruitful hunting ground for Cretaceous crocodilians. They're great, but I'm a little partial to Deinosuchus - a fellow southerner.

Not us this time?

Another look at the Pleistocene decline of a large North American mammal, although in this case the species survived. And, perhaps more surprisingly, this time we're not the agent of disaster. A study coming out in the new PNAS looks at the dramatic reduction in numbers of musk ox which began about 12,000 years ago and concludes that the major cause was climate change, rather than human impacts.

The researchers analyzed mitochondrial RNA from musk ox remains up to 60,000 years old from areas across their former range. They then applied statistical techniques to investigate changes in the genetic diversity of musk ox over their North American history. They found that genetic diversity, an indicator of population size, declined several times over the last 65,000 years. They also found that changes fluctuations in the size of musk ox populations did not mirror those of other North American megafauna like mammoths and bisons, suggesting that population declines can not be attributed to an invading horde of overzealous human hunters.

The more I read about Pleistocene extinctions, the more convinced I become that there's simply not an easy answer.

New annelids...

Serendipity. My zoology guys have left the mollusks behind and moved on to the annelids. There aren't as many juicy little tidbits about annelids. And yet, we get worm-grunting in the Florida Panhandle and new species of the annelid genus Grania scattered around the world. Grania are a genus of small interstitial marine clitellates, typically a couple of cm in length. They're the subject of the Ph.D. dissertation of Pierre De Wit at the University of Gothenburg. The image at left is Grania maricola (which I stole from Pierre's web page - hope you don't mind, P). Most are white, although Grania colorata, a newly discovered species from the Great Barrier Reef, is green. One called Grania occulta looks so similar to previously described species that it can only be identified by DNA analysis. Congratulations, Pierre. I've had some experience working with interstitial inverts - you've earned a beer.

Gas day

No, not talking about a trip to the Mexican restaurant. An apparent gas leak closed our building for the afternoon, and cancelled classes. The result - a couple of hours on the Sucarnochee.

Worm grunters

Can't wait for this from Scientific American. Worm grunting is sort of tradition in the Florida Panhandle where I grew up. One of the few memories I have of my dad is a grunting expedition in our yard when I must have been 5 or 6. Sopchoppy (that's right, Sopchoppy) is the unofficial worm-grunting capitol, and home to the annual Worm Gruntin' Festival (the "g" must be excluded), with the 10th annual edition coming up next month. Biological significance? Well, no less an authority than Charles Darwin speculated that the worms come to surface because they interpret the vibrations as a foraging mole. This in his 1881 book, The Formation of Vegetable Mould. There were doubters, but Darwin's ideas were supported by this work by Vanderbilt's Kenneth Catania.

The Panda's genes

A study in Nature describes the efforts of a large group researchers to sequence the genome of the giant panda, Ailuropoda melanoleura. The full text of the paper is available here - for the Cliff Notes, check it out at Science Daily. Lots of interesting findings. For one, there's no indication of a genetic basis allowing for the digestion of bamboo. Pandas, recall, feed almost exclusively on bamboo. This suggests that they may harbor a gut flora that enables them to process their food, much the same way that the gut flagellates of termites enable them to enjoy your otherwise indigestible house. The researchers did find mutations in the panda's TIR1 gene, which might affect their ability to taste meat - a possible explanation for their their gastronomic differences from their ursid cousins.

One very bright spot - no signs of excessive lack of heterozygosity that are often associated with small populations. That bodes well for the pandas survival. Really nice example of the enhanced understanding that 21st Century techniques are going to bring to a wide range of disciplines.

More whales

Bess and I ran this morning with Phillip Hoare, and today he was talking about the North Atlantic right whale, Eubalaena glacialis. The cetacean experts in the crowd will know that they were called the right whale because of their suitability for whalers, i.e., they were the right whale to kill. One reason is their very high fat content, which made them profitable, and also made them float when they expired. Depressing to hear, but part of our past nonetheless. The northern right is one of the most endangered of all mammals, maybe at the top of the list. (Quiz Question: how many remain?). They're actually pretty fecund, but they're also prone to disaster. As of now, the rate of loss is keeping pace with new births.

Phil's book is entertaining, even though it's a little lacking in scientific rigor. I also find myself losing track of whether Hoare is speaking himself, or quoting one his many sources ranging from Shakespeare to Thoreau. Lot's of Melville, of course. I guess I'll have to reread Moby Dick, although that'll to have to wait for a semester break.

Hoare is particularly impressed with the right's testicles, which apparently weigh more than a ton. Gonna have to look that one up.

I guess I'm enjoying The Whale. It's motivated a summer trip to Boston, with a junket to Nantucket. There's a limerick in there somewhere.

Regardless, for your pleasure...