Thursday, July 12, 2007

Brightly Colored Birds More Affected By Chernobyl

On ScienceDaily today, a really fascinating report on how the Chernobyl meltdown has affected some bird species more than others. They studied 57 species, and found that those that have had the most drastic declines since the disaster fall into four groups:

1. Species that depend upon dietary carotenoids for their red, yellow, or orange plumage (orioles, blackbirds, blue tits, for example).
2. Species with relatively large eggs.
3. Species that migrate.
4. Species with wide dispersal patterns.

Apparently all of those groups have lifestyles that place a high demand on antioxidants (for plumage coloration, flight energetics, etc). The study suggests that high levels of radiation have a disproportionately negative impact on species that require lots of antioxidant compounds. Radiation levels in a normal (ie not post-meltdown) environment vary due to natural things like differences in isotopes between different geological features, and the researchers suggest that these new discoveries can be used to make predictions about species success in places where radiation levels can be quantified.

It is important to realize, from the data in their report, that some of the species studied fall into more than one of the high-risk groups: for example, orioles depend on carotenoids for their yellow plumage (see image above), and also migrate long distances.

Also, another thing I gathered from the report that I thought warranted a note: bird species that are taxonomically close might not be impacted to the same degree as less-related species with similar lifestyles (meaning, you can't necessarily predict the impact on a species by looking at stats on a sister species). For example, in the family Paridae, blue tits, which are highly dependent on carotenoids, have faced much sharper declines than coal tits.

I've always been fascinated with the Chernobyl meltdown (it's one of the landmark events in the year I was born, btw) and its impacts on the local wildlife. Despite my unabashed mammal and dino bias as far as interests go, the radiation-eating fungus recently discovered there is still definitely my favorite science story of 2007 (see my blog post on it here). One thing that is both interesting and sad is that some reports have shown that wildlife has actually benefited, in some ways, from the catastrophe, since human activities in the area have effectively ceased.

Wednesday, July 11, 2007

Quotes of the day

"How is it that hardly any major religion has looked at science and concluded, 'this is better than we thought!' The Universe is much bigger than our prophets said, grander, more subtle, more elegant'? Instead they say, 'No, no, no! My god is a little god, and I want him to stay that way.' A religion, old or new, that stressed the magnificence of the Universe as revealed by modern science might be able to draw forth reserves of reverence and awe hardly tapped by the conventional faiths."
Carl Sagan in The Pale Blue Dot



"The distinguished embryologist Lewis Wolpert once admitted that science is occasionally arrogant, and he went on to remark, mildly, that science has a certain amount to be arrogant about."
Richard Dawkins in Unweaving the Rainbow

Monday, July 9, 2007

Worm-like jellyfish

There is a really fascinating article on Science Daily today about Buddenbrockia, a small organism previously that has long been thought to be a nematode worm, but now known to be most closely related to anemones and jellyfish. It has no gut, mouth, brain, or nerve cord, and although it was long thought to be a type of nematode, it has a very different body plan (the main distinction: Buddenbrockia is symmetrical).

Researchers from the University of Oxford compared 50 genes with a variety of organisms to determine where this enigmatic species fits into the animal kingdom.

There are practical implications for this as well: apparently Buddenbrockia is closely related to a parasite that causes trouble for salmon farms (I don't have time to go into my issues with salmon farming the first place, though...). Current and future studies of it will hoepfully shed light on how to conquer the parasite, although I think that the taxonomic revelations are pretty cool all on their own.

(Photo credit: University of Oxford)

Sunday, July 8, 2007

Could you solve it?

Scenario: You are shown a tall cylinder with a tasty nut in the bottom. How do you go about getting it out, assuming the cylinder is too tall and narrow for you to reach the bottom, and that it is fused to a tabletop (you can't dump it out)?

Could you create a strategy for getting the nut? Orangutans in one study showed amazing problem-solving skills to obtain the nut: they took mouthfuls of drinking water and spat into the cylinder, to make the nut float within finger-grasping range.

The five orangutans tested needed an average of nine minutes to realize that they could float a peanut to the top of the container, you can see an example here:



Pretty amazing, I think! Orangs are infamous for using tools and escaping enclosures in captivity (read about the legendary escapades of Fu Manchu here), which is interesting because in the wild they have not been observed to use tools to the same degree as other apes, or to captive members of their own species.

If I could pick one primate to study it would definitely be the orangutan, there is so much about the species that is unique from the other great apes. They are so imperiled right now, though, and often from places people wouldn't expect, like efforts to promote biofuels instead of fossil fuels. You can learn more about orangutan conservation efforts here, the statistics are very disturbing.

Thursday, June 28, 2007

Van Roosmalen sentenced to 14 years in jail

Earlier this month I did a post on Marc van Roosmalen, a zoologist that has discovered an unbelievable number of new vertebrates during his career. I came across this news story today and was shocked, apparently he's been sentenced to 14 years in jail for "theft and biopiracy", as a result of failing to apply for permission to create a monkey refuge at his home. The linked article speculates that this happened because his efforts toward promoting conservation have made him a nuisance to Brazilian authorities.

According to the Primatology.net blog, if an application like this is not rejected within 45 days it is generally assumed to have been accepted, which is what van Roosmalen apparently did without realizing it had been rejected...although he has been accused of never filing it in the first place. I think it sounds like a very suspicious situation, pretty convenient for the officials to lose the document and then have a reason to arrest the scientist. He is appealing the decision, hopefully it will be overturned, he is 60 years old and a 14 year sentence would end his career and all of the conservation efforts he is making.

Tuesday, June 26, 2007

Giant penguins in Peru!

Fascinating press release today, this week's Proceedings of the National Academy of Sciences, has a paper describing two new species of fossil penguins, found in the Atacama Desert (Peru).


One species (Icadyptes salasi) dates from 36 mya, and stood 4.5 feet tall. the second species (Perudyptes devriesi ) is older, from 46 mya, and stood about 3 feet tall, roughly the same as modern King Penguins. There are still penguins in South America today Spheniscus humbolti), but the extant species is only about 2 feet tall.

This find is interesting because it pushes the appearance of penguins in this region back by about 30 million years. It is also fascinating because such large birds were present in a relatively warm climate, apparently early penguins were not the cold-specialized birds that we see around us today.

This find looks like it could rewrite the known history of the Spheniscids, the new specimens definitely hold promise to reveal much more about penguin evolution than what was previously known.


Friday, June 22, 2007

"Vaccine" to ease drug withdrawal symptoms

Interesting story today about a new vaccine designed to help ease withdrawal systems for people recovering from cocaine and methamphetamine addictions.

The treatment works by stimulating the body to produce antibodies that attack the drug while it is in the bloodstream, resulting in less of the substance being processed, gradually weaning the brain from the chemicals. It is emphasized that this is NOT a wonder drug to cure addictions or prevent relapse, but is a "therapeutic" which can help to ease the extremely painful process of withdrawal.

This sounds great, but one thing I wonder is the risk for stimulating autoimmune disorders. Drugs affect us because many chemicals imitate natural substances, fitting into brain receptors that already existed for something else. If you produce antibodies against cocaine, for example, will they also attack dopamine (which cocaine "imitates), which is crucial for healthy brain function, and is also very similar to adrenaline? I'm sure this will be addressed in tests, it will be interesting to monitor news on this.

Wednesday, June 20, 2007

Did some dinosaurs survive the K-T event?

Interesting discussion in the world of paleontology today, apparently a study has been published in New Mexico Geology suggesting that dinosaur remains have been found in Paleocene (post-K-T event) layers of rock. Here is the abstract:

Extensive geochronologic studies of the rocks adjacent to the Cretaceous-Tertiary (K-T) interface in the San Juan Basin have now provided compelling data attesting to the Paleocene age of the dinosaur-bearing Ojo Alamo Sandstone in New Mexico and the Animas Formation in Colorado. These data consist of radiometric age determinations for Cretaceous strata underlying the K-T interface and palynologic, paleomagnetic, and geochemical evidence attesting to the Paleocene age of the strata above the K-T interface. The identification of the paleomagnetic normal interval - C29n - in the dinosaur-bearing lower part of the Ojo Alamo Sandstone in the southern San Juan Basin at multiple localities allows for the precise dating of the last occurrence of Paleocene dinosaurs at the top of chron C29n at 64.432 Ma.

The conventional wisdom (entrenched dogma) among most geologists, and especially among vertebrate paleontologists has been, for more than 100 years, that all dinosaurs became extinct at the end of the Cretaceous. Thus, dinosaur bone found in place in a formation provided indisputable evidence that the formation was Cretaceous in age. Now, with the discovery of Paleocene dinosaurs, the paradigm of Cretaceous-only dinosaurs must shift. Let us hope that this paradigm-shift will be a smooth and placid lateral-slip along planar fault blocks rather than a grumbling, rumbling, herky-jerky sliding of jagged-edged, opposing sides past each other. Science must always be conservative and accept such paradigm shifts only on the basis of the most solid evidence, however, when the data do finally speak, the shift must be accepted by all of us who follow the data in the noble pursuit of finding out how the world was made.

This thread on the Dinosaur Mailing List (link is to the archives, updated daily) has discussion from the experts. Apparently the author of the new paper has argued for Paleocene dinosaurs before, without much success. It is also pointed out that if there were incontrovertible evidence for this, it would definitely be Science or Nature worthy, and wouldn't be relegated a fairly obscure journal. Every field needs its left-field theorists to keep things interesting, I suppose, and it is at least interesting to hear theories and it's beneficial when they can be proven wrong because it makes us review, analyze, and apply what we do know in order to refute inaccurate claims. That, my friends, is the beauty of science.

That being said, I'm sure the creationists will be flocking to this like ducks to holy water. Weird claims don't annoy me that much as long as they're taken seriously, but the downside is that someone, somewhere, always takes it seriously, it makes me sad for them.

Thanks to John Wilkins at Evolving Thoughts for digging up the story.

Ancient species of panda discovered

News from National Geographic this week: a fossil "pygmy" panda was discovered, a species that lived 2-3 million years ago. The species, named Ailuropoda microta, was only about half the size of modern pandas (Ailuropoda melanoleuca). Shown below is the skull of A. microta compared to A. melanoleuca


Interestingly, this early species already displayed adaptations for a diet consisting primarily of bamboo, including certain cranial/dental features and the infamous "false thumb" that aids pandas in stripping the leaves from bamboo. Pandas appear to have depended upon bamboo for millions of years now, I don't know if they have shown any evidence of co-evolution but it would be an interesting thing to look into.

I've always thought pandas were interesting, because they're an example of an animal that has a slightly oxymoronic taxonomic classification, being found in the order Carnivora despite their herbivorous lifestyle. Also, few people are aware that there are actually two extant subspecies of giant panda, the classic Ailuropoda melanoleuca melanoleuca that we all know and love, plus the less famous A. melanoleuca qinlingensis. This subspecies, known from the Qinling mountains, has brown fur and a slightly smaller skull.

Wednesday, June 13, 2007

Gigantoraptor erlianensis

I love dinosaur news days: I just got this from the National Geographic news site: Massive Birdlike Dinosaur Unearthed in China. Gigantoraptor erlianensis!


This is great because while the fossil didn't preserve feathers, closely related species have been shown to have them so it seems reasonable to infer that this species did too. Having a "very birdlike appearance", it was over 16 feet tall. This makes the evolution from dinosaur to modern birds more intriguing, since it is the biggest "birdlike dinosaur" yet uncovered and raises questions about the role that size reduction played in that evolutionary pathway.

Another thought I had was that it also gives more evidence that feathers were a preadaptation for flight and that flying was not their first function, this dinosaur obviously wasn't going anywhere. Of course it is possible that it is secondarily flightless, the flight issue wasn't addressed in the announcement, but once I get the paper I'll report back if it has any insights on that topic.

What a pain in the neck...

Really fascinating story: a bowhead whale was found with a 19th century weapon embedded in its neck.

The whale was caught off the coast of Alaska, and apparently had escaped an earlier attempt at capture over a century ago. Judging from the age of the weapon (a fragment of a bomb lance, manufactured in New Bedford, Massachusetts), the whale's age is estimated to be about 115-130 years.

As the news article mentions, whales are thought to have extremely long lifespans, in some cases 200 years or more, but it is hard to determine exactly. The journalist makes a passing reference to the use of amino acids in the eye lenses. This was actually covered in a fascinating paper in a recent issue of the Journal of Mammalogy:

Garde, Eva, Heide-Jorgensen, Mads Peter, Hansen, Steen H., Nachman, Gosta, and Forchhammer, Mads C. 2007. Age-specific growth and remarkable longevity in narwhals (Monoceros monoceros) in Greenland as estimated by aspartic acid racemization. Journal of Mammalogy. 88(1): 49-58.

The abstract:
Eyes from 75 narwhals (Monodon monoceros) were collected in West Greenland in 1993 and 2004 for the purpose of age estimation. Age estimates were based on the racemization of l-aspartic acid to d-aspartic acid in the nucleus of the eye lens. The ratio of d- and l-enantiomers was measured using high-performance liquid chromatography. The aspartic acid racemization rate (kAsp) was estimated to be 0.001045/year ± 0.000069 SE by regression of d/l ratios on age estimated by length from 15 young narwhals (≤298 cm) and by earplug laminations from 13 fin whales (Balaenoptera physalus). The d/l ratio at age 0 ((d/l)0) was estimated to be 0.0288 by regression of d/l ratios against the estimated age of the 15 young narwhals. The intercept of the regression slope, providing twice the (d/l)0 value, was 0.05759 ± 0.00147 SE. The maximum estimated age was a 115-year-old (±10 SE) female. Asymptotic body length was estimated to be 396 cm for females and 457 cm for males, and asymptotic body mass was estimated to be 904 kg for females and 1,645 kg for males. Using the von Bertalanffy growth model, age at sexual maturity was estimated to be 6–7 years for females and 9 years for males.


At the time I thought this was an extremely fascinating article (the use of racemization might be the first time I was actually glad I'd taken organic chemistry!). The new bowhead find confirms that whales can live well over a century, sometimes even despite the efforts of armed humans.

Sunday, June 10, 2007

In which I am reminded of why I love being a zoologist

On Friday we took a trip down to a couple of national monuments, Montezuma Castle (amazing cliff ruins, occupied 1250-1400 AD) and Montezuma Well, the result of the collapse of a limestone cave that created a huge well filled with warm, fresh water, it's like an oasis, it was amazing.

I'm an anthropology minor so all the Pueblo ruins were fascinating, but the wildlife was what really made the day great, I added a two new mammals to my life list, and a few birds and lizards as well. Here are some of my favorite shots from the day:

Botta's pocket gopher (Thomomys bottae):



Rock squirrel (Spermophilus variegatus):


Common Merganser (Mergus merganser), female with brood:



Cave swallows (my pictures if of the nests, couldn't get a good shot of the birds so the bird pictures is from the Cornell site), Petrochilidon fulva:


We also saw Canyon Wrens (Catherpes mexicanus) and Gambel's Quail (Callipepla gambellii) at Montezuma Well, but I couldn't get my own pictures, credit to the Cornell site for these:




Overall it was an awesome day, I love Western habitats, I wish more people realized how rich the "desert" is in biodiversity!

Tuesday, June 5, 2007

24 new species discovered

Science Daily has a really interesting news article today about 24 new species discovered in the Suriname rainforest. What's interesting about this is that the biologists are working for a mining company, which is taking measures to get biodiversity surveys done before planning a new site. Awesome example of one of the discoveries:


Monday, June 4, 2007

Arizona wildlife sightings

I have been in Arizona for almost a week now, and have added some great animals to my "life list":

Mammals (photos taken by me):
Golden-mantled ground squirrel (Spermophilus lateralis):


Gunnison's prairie dog (Cynomys gunnisoni):


Those are babies, the first day they emerged from the burrow!

Birds (photos not by me, I'm not fast enough for bird photography, apparently):

Western Tanager (Piranga ludoviciana):


Lesser Goldfinch (Carduelis psaltria):


Broad-tailed hummingbird (Selasphorus platycercus):

My own poor attempt of a photo at dusk:


An identfiable picture:


I also really want to see an Acorn woodpecker and a Lazuli bunting before I leave.

First real day of field work in the prairie dog colony tomorrow, I'm excited!

Underwater tiger

Awesome picture for the weekend:


Taken from National Geographic's news photo gallery.

Energy fiend

I have been griping for a long time about how nutrition labels should include the number of mg of caffeine per serving in a drink (or food). I'm not sure if that will happen in the future or not, but in the meantime there is this really interesting website, with a database of the caffeine content of most of the common sodas/energy drinks/coffees on the market.

Just as a baseline, coffee has about 107 (brewed) to 145 (drip) mg per cup. I was surprised to see that many energy drinks actually have less caffeine than a cup of coffee, although some have disturbingly high counts: the 'winners' are Boo-Koo Energy, and Zero Carb Rockstar, each with 360 mg.

I also thought it was interesting that the Zero Carb version of Rockstar has more than twice the caffeine of the regular version, which has just 150 mg. Hmmm.

Anyway, another cool feature on the site is a little gadget that tells you how much of an item you would have to consume to get a lethal dose of caffeine. Just for the record, it would take 19 cans of Zero Carb Rockstar to kill me, but I could drink 47 cups of brewed coffee before kicking the proverbial bucket. Rock on.

Saturday, June 2, 2007

Sinosauropteryx controversy: bald or feathered?

National Geographic has a really surprising news story today, apparently reanalysis of the infamous Sinosauropteryx fossil (showing exquisite preservation of feather structures) is calling the previous conclusions into question.

This should be taken with a grain/shaker of salt, however, since there have been dissenters from the very beginning claiming that the structures are actually collagen fibers, not feathers. The reason the news story is surprising, to me, is that NG chose to cover it, when the squabbling has been raging for years now, not that someone is actually claiming the fibers aren't feathers.

The whole topic is controversial because some scientists cling to the view that birds actually predate dinosaurs, and are not their descendants, despite plenty of evidence to the contrary. There is a great summary of the debate here, and in the mean time it will be interesting to see if there is any rebuttal to this latest flare-up of criticism in the media.

Monday, May 28, 2007

Leavin' on a jet plane

Tomorrow I fly out west for my summer research internship, I'm going to drop my dog off today, stay with family near Atlanta overnight and fly out of there in the morning (yay for 8 AM departures...). Not sure what my daily schedule will be like once I get out there, but I'm going to try to keep up with posting interesting stories. Anyway, just felt the need to make a note of this, I'm pretty excited about the summer research and am anxious to get out there and get started.

Sunday, May 27, 2007

Pawprint evidence

Really interesting news today, an announcement on a study of what is apparently the only carnivore known for a fact to have distinct "fingerprints" that can be used to identify individuals. (Although it is suspected that many other species do also, it hasn't been studied very well yet).

This honor goes to the fisher, a mustelid (close relative to weasels) that typically inhabits coniferous forests and ranges from the Sierra Nevada of California to the Appalachians of West Virginia and Virginia.

What is especially fascinating about this story is that the identifying patterns on the fisher's toe prints are made of dots, not the swirly lines that form human fingerprints.

This seems like it should really be studied in more carnivores, because they are notoriously hard to track/observe in the wild. This would be a great way to keep track of activity patterns of individuals without having to stress both animals and humans with contact, and I would think it would allow more accurate population estimates from tracking, so that a given individual won't be counted repeated times. Cool stuff!


Minty fresh bee hives

There has been a lot of coverage in the news about the dramatic crashes in bee populations (termed colony collapse disorder, or CCD) that are sweeping the country, and also appear to be happening in Europe as well. The exact causes are puzzling bee experts, and the whole problem is pretty enigmatic so far. There are many different possible reasons for the die-offs, just a few are climate change, pathogens, pesticides, mites, and (yes, this has been suggested) the wave emissions from cell phones.

But one interesting study was reported last week: researchers have had success in protecting hives from CCD by treating hives with oils derived from spearmint and lemon grass. These substances are being marketed as Honey B Healthy, but the practice of using lemon and spearmint in bee-keeping can be traced back 60,000 years.

The procedures (detailed in the ScienceDaily article) help to protect the hives from bacteria and other pathogens, in addition to killing up to 93 percent of the mites in a hive after just one day of treatment.

Hopefully this will be applied on a larger scale and will help to prevent further declines. The amount of time the popular media has given to this issue has been pretty extensive, a good example of how conservation efforts tend to be boosted immensely when human economic activities are at stake ($6 billion in California alone). While all of our popular produce items (for example, apples, nuts, avocados, soybeans, asparagus, broccoli, celery, squash, cucumbers, peaches, kiwi, cherries, blueberries, cranberries, strawberries, cantaloupe and other melons) are threatened, the beef industry is also in a perilous position because cows are, obviously, herbivores, and bees are key in pollinating the alfalfa used to sustain cattle.

I'm very glad that so much attention is being given to this issue, but it does highlight just how selective we tend to be about conservation. Who is out there campaigning for the Zayante Band-winged Grasshopper, another endangered insect from California? Its populations have declined due to urban development and sand mining, aka human economic activities...so the issues that eliminate one species may save another. Such is our world, hopefully the bee issue will make people more aware of conservation concerns in general and will lead to increased attention to things like this in the future.

Fire haze

I live in Alabama, and here in the southeast fires are an important part of the ecology of this region. The longleaf pine savannahs depend on periodic fires to maintain balanced climax communities. Longleaf pines are adapted to be fire resistant, and the heat from fires aids their germination. Without these fires, the understory grows up and hardwoods can begin to move in and crowd out the longleafs. Fire suppression has been a major threat to these ecosystems, although now that the ecology is better understood prescribed burns are being conducted to simulate the natural processes.

So, fires can be good. Sometimes, though, natural and/or anthropogenic fires are big and uncontrolled enough to be a major concern, like the recent wildfires in southerneastern Georgia and northern Florida, which is what spurred me to make this post. The fires were started by lightening strikes last month, and this turned into disaster due to the drought conditions encompassing much of the region. The fires have destroyed 700 acres of swamp and timber land so far.

I got up this morning and it smelled like a fireplace in my house, because I'd left my kitchen window cracked and the huge hazy cloud that had covered my town was creeping in. When I was out walking my dog around 9:00 this morning, there was a big smoglike cloud over the city, it was very strange looking for a small, compact town to have an L.A.-like smog cloud hanging over it, especially considering we are hundreds of miles west of the fires. I read that the clouds are even stretching to Mississippi. due to a high pressure system from the east combined with strong southeastern winds. It had mostly cleared up by this afternoon/evening. I'm not a meteorologist, but it would be interesting to learn why the smog effect is most pronounced in the morning.

Saturday, May 26, 2007

Dinosaur bonanza

There have been a ton of fascinating dinosaur stories in the news lately, I've got some catching up to do. While I am now studying to be a zoologist (I like to think that I already am a zoologist, this past semester I got my first collecting permit for research in a national forest), paleontology was what first drew me into science, I hit the usual dinosaur phase when I was a kid, but never really grew out of it. That led to an interest in evolutionary biology, which led to a fascination with the diversity resulting from evolution, then an intense interest in the ecology that links organisms and their environments, and I guess it all snowballs, and thanks to a preschool infatuation with The Land Before Time, here I am.

Anyway, news!
First, researchers at the University of Alberta have analyzed CT scans ofvarious theropod skulls, comparing tyrannosaurids with non-tyrannosaurids (such as carnosaurs) to see if they could find any taxonomic trends. Some of the features analyzed were tooth-bending strength and the strength of the cranium and nasal bones.

The results: T. rex is once again shown to be an ultra-predator, with fused nasal bones that created superior strength and bite force. In addition to strengthening the skull, having fused nasals provided larger attachment area for muscles, allowing for immense forces to be applied by the jaws.

So just how strong was the T. rex? From the ScienceDaily press release:
A medium-sized T. rex had even more skull strength than a larger carnivorous creature, such as the Carcharadontosaurus saharicus, with a head nearly one and a half times as long. T. rex's neck power was similarly staggering. For instance, in a split second, a T. rex could toss its head at a 45 degree angle and throw a 50kg person five metres in the air. And that's with conservative estimates of the creature's muscle force, says Snively. "We kept the muscle numbers down because we thought they couldn't possibly be that powerful, but Tyrrell museum colleagues showed that a T. rex's lower jaw could apply 200,000 newtons of force--that's like lifting a semi-trailer," he said. "All of the T. rex's features came together to give it the strongest bite of any land animal. The T. rex just blows everyone out of the water when it comes to strength.

What could be scarier than an animal that can carry a truck like a chew toy? One that can chase you on both land AND water! Earlier this week the Geological Society of America announced the discovery of a new dinosaur trackway in Spain. There are many known dinosaur trackways, but what makes this one noteworthy is that it gives us the strongest evidence to date that some dinosaurs could swim.

The 15 meter long trackway at the La Virgen del Campo track site in Spain’s Cameros Basin includes 6 asymmetrical pairs of scratch marks that were identifiable as belonging to a large theropod. Theropod tracks had previous been found in nearby areas known to be on the shoreline of the prehistoric lake. The prints were slightly S-shaped, and one of the authors of the paper, Loic Costeur of the Laboratoire de Planétologie et Géodynamique de Nantes, Université de Nantes, France, said that this is consistent with the marks left by a large animal clawing its way along sediment. The rippled patterns of the surrounding ground confirm that the prints were made at the bottom of a body of water.

You don't have to be big and fierce to leave your footprints on history, however: this week another interesting trackway discovery was announced, this one featuring a tiny print from a stegosaur hatchling. The prints were about the size of fifty-cent pieces, absolutely amazing when you consider that adult stegosaurs grew to 26-30 feet long and weighed up to 2 tons!

This makes me wonder about the growth rate of those creatures, how long did it take an animal the size of a human baby to reach the size of a bus? A lot of it has to do with metabolism, which is definitely an area of contention among paleobiologists. I'm not sure how much of an ontogenetic series of fossils there is for stegosaurs, I know they have pretty complete ones for some hadrosaurs, but you can't always generalize across species.

Anyway, that's today's dose of paleo-news!

Friday, May 25, 2007

On becoming a cow

Most people are familiar with the story of how vaccination was invented, but I'll give it a brief review before getting to the point of interest: in 1796, Dr. Edward Jenner conducted an experiment (which would have been highly illegal in modern times), by collecting pus from a cowpox pustule of a milkmaid, Sarah Nelms, and injecting it into a little boy, James Phipps. (No, the names don't matter, but I like character-driven plots).


At this time smallpox was a major public health problem, up to one in three children died from the disease. Cowpox, however, was common but nowhere near as deadly. After little Phipps was injected with the the Nelms pus, he developed a characteristic cowpox pustule, but was relatively no worse for the wear.

Six weeks later, Jenner exposed Phipps to smallpox in the same manner. Not only that, he was insistently exposed over a period of years (where were this kid's parents, and what were they thinking?), and yet he never contracted the highly virulent disease. Thus, it was proven that exposure to a virus can stimulate the immune systemto fight off similar viruses in the future, and vaccination was born.

This story is familiar to most people who have had an introductory biology class. What most people don't know, however, is the origin of not the concept of vaccination but the word itself.

Since the mechanism of immunity was not yet know, many people, including the French, ridiculed Jenner's idea. In stereotypically snooty fashion, they coined a mocking term for the procedure: "vaccination" is derived from vache, the French word for cow. If you translate it literally, the term roughly means "to be made into a cow."

I'm just as much of a book lover as a science lover and am fascinated by the evolution of both words and species, just thought that was an interesting item to add to Jenner's well-known story.

Thursday, May 24, 2007

Radiation-eating fungus

There's a really amazing story on ScienceDaily today, about a species of fungus that produces energy from radiation.

What I found most fascinating is that this appears to occur only in fungi that contain melanin. Considering what a vital role melanin plays in our own bodies, to me it seems like this seems like another piece of evidence that fungi are actually more closely related to animals than plants, but that wasn't addressed in the press release.

One thing they did mention, however, was using this as a food source during space travel. That got my imagination going...if it produces energy from radiation, imagine incorporating it into a food you could fortify by zapping in the microwave for a minute or two! ;)

Wednesday, May 23, 2007

Water, water, everywhere

I drink a lot of water, sometimes it feels like abnormally much but I really just get very thirsty. This week I decided to quantify exactly how much water I consume every day, I like experiments. So for the past few days I've monitored my water intake, making sure it's absolutely consistent with my normal routines, I poured water from the measuring container into the glass I always drink out of, to make sure my habits would be completely as usual, no effect from drinking from different apparatus. Just for the record I do NOT waterload or drink just to kill hunger, I genuinely only drink as much as I am thirsty for.

So, the result? My water consumption averaged 219 ounces per day, 3.4 gallons, confirming the hypothesis that yes, I do indeed drink a lot of water. I also have one non-water drink with every meal (for example, yesterday: 16 oz of coffee, 16 oz of Crystal Light lemonade, 12 oz of Diet Ocean Spray cranberry juice), including those brings my average liquid consumption up to 4.2 gallons. I mentioned this to my mom and she freaked out, telling me that I am drowning myself and need to talk to a doctor about it.


But I don't think it's that unreasonable if you consider that it summer in Alabama, and that I spend several hours exercising every day. Example: yesterday I got up, ran 3 miles on the treadmill, walked Charlie for two miles, walked to campus and back (3 mile round trip), road the stationary bike for 12.8 miles, walked Charlie for another 4 miles, did 50 minutes of sit ups, 15 minutes of leg lifts, and 10 minutes of reps with light weights. This is a typical day, and with typical Alabama weather, so yes, I get pretty damn thirsty. I also use a LOT of salt on my food, which could be another factor. One other point of analysis, a couple of years ago when I had bloodwork done for something they told me that one of the hormones affecting kidney function was slightly out of whack (I can't for the life of me remember which one, possibly ADH?), which has a major effect on osmoregulation, but they didn't suggest really doing anything about it.

I have only had one time when I felt like I'd consumed too much, back in my senior year of high school. At that time I was having major bouts of insatiable thirst, it was weird and I SHOULD have seen a doctor about it but didn't. It was in one of my physical low periods. Anyway, one afternoon I came home from school, ran on the treadmill as usual, and chugged down at least 40 ounces of water in about fifteen minutes. Then my vision got really swimmy, I had tons of pressure in my head, and could feel myself teetering on the edge of a blackout. I freaked out, and in my unfocused panic tried to think of how to fix it, and grasped at the idea that the opposite of water should be salt, so I ate a spoonful of salt and laid down for a while, after a while it was ok again, but it was overall very scary. But anyway, that was an isolated event and even at that time, I had genuinely felt thirsty for every ounce of what I drank, I wasn't waterloading. I've never had anything like that happen since, but thought it was a story worth noting, I think it was probably a brush with hyponatremia, but I am not a doctor.

So, although I don't usual make personal posts on this blog, I just felt like sharing the results/analysis of my mini science experiment, I think I may invest in a water filter, since I don't really trust Auburn city water (I've seen the nasty results of those occasions when they push high pressure through the pipes to clean them out, gag).

Saturday, May 19, 2007

How many endangered species are there?

While Endangered Species Day was officially yesterday, in today's world every day is an endangered species day, so I have another ESA themed post.

Last night a friend of mine asked a deceptively simply question: "I don't know if this is a stupid question or not...how many endangered species are there?"

Not a stupid question at all, actually an extremely important question with a complicated answer.

Right now there are 369 animals and 593 plants listed as endangered under the ESA, and 217 more (plants and animals combined) are classified as threatened. BUT keep in mind tht these are just the ones that made it through all the political gauntlets to get listed (it is terrible to get a species approved, because it automatically restricts use of its habitat, which costs important people money, and that pisses them off). Also, that number is restricted to animals that live in the US.

There are 567 species classified as endangered in other countries, but since most of the areas with the most biodiversity also have the least stable governments and the least scientific funding, this is nowhere near the number that would be recognized/protected in an ideal world.

Also, note that a single species (under the US system) carries two ratings, one for global and one for state. For example, the red wolf is extinct in Alabama but endangered globally. A species can be locally common but very rare worldwide, like some fish that inhabit just a single pond in a single state.

Just out of curiosity, I looked up the listed species in Minnesota (my friend's home state) for her, there are 16 (endangered unless noted otherwise):

Animals:
American burying beetle
Bald eagle (Threatened)
Gray wolf
Karner blue butterfly
Eskimo curlew
Higgins eye pearly mussel
Canada lynx (Threatened)
Scaleshell mussel
Piping plover (listed as only threatened everywhere except the Great Lakes watershed, where it's endangered)
Topeka Shiner
Winged mapleleaf

Plants:
Prairie bush-clover (threatened)
Minnesota dwarf trout lily
Western prairie fringed orchid (threatened)
Leedy's roseroot (threatened)

Not too bad, 16 is very low, my homestate of TN has 90 and AL has 117. This correlates to biodiversity, too, though, I'm not sure what percentage of species in each state is endangered. AL is number 5 in the nation for biodiversity (number 1 for aquatic animals!), so naturally there are more species that can potentially be listed. That doesn't save us from trouble, though, we're 2nd in the nation for extinction RATE, behind only Hawaii, which is a very bad thing.

One other note, botanists complain (justifiably) that plants are extremely neglected by the ESA. Considering there are tons and tons more plants than animals in the world, there are also many more endangered ones, but they usually fail to get the attention/support of animals. Face it, people care more about eagles than louseworts. Just thought I'd mention that, though, because it is an example of how numbers are easily skewed by politics and don't actually represent the status of things in nature.

So, a very good question but unfortunately no good answer.

The endangered Furbish lousewort

Friday, May 18, 2007

Endangered Species Day 2007

In case you aren't aware, today is Endangered Species Day. May 18 is the anniversary of the day that congress first approved the Endangered Species Act. There has been a lot of controversy and corruption over the details and handling of the ESA, but it has achieved many goals as well, and today is earmarked for raising public awareness and support. So, happy Endangered Species Day, everyone, and make sure to spread the word!

Thursday, May 3, 2007

MacDonald resigns from the USFWS

Big story in the news today: Julie MacDonald, an Interior Department official in charge of overseeing the Endangered Species, resigned in light of news about various corrupt actions over the past years. It has been shown that she leaked important documents to industry officials, and altered scientific reports so that they gave less support for protection of endangered species. Absolutely despicable, I really hope this is the end of her political career as a whole.
Among the species affected by her corrupt actions are the Gunnison's prairie dog (which I've got an NSF grant to study this summer!), the White-tailed prairie dog, the Gunnison Sage Grouse, the Roundtail Chub, the Marbled Murrelet, the Delta Smelt, the wolverine, the Florida panther, the Trumpeter swan, the bull trout, the grizzly bear...

Sunday, April 29, 2007

Dinosaur skin!

This week there were reports about a fossilized dinosaur skin found in Japan. This is not the first time dinosaur skin impressions have been found preserved on rocks, the most famous being a fossil often referred to as "Leonardo the mummy dinosaur," a hadrosaur which has been a paleontological celebrity for many years now. Leonardo's fossilized skeleton was covered in soft tissue—skin, scales, muscle, foot pads—and even the remains of the meal that was in his stomach when he died.

The new find is thought to be from the leg of an herbivorous dinosaur--there is still controversy over the exact species, but some Japanese researchers have speculated that it could be Fukuisaurus. The impressions show polygonal scales about 4 mm in diameter, similar to the pattern seen on Leonardo. It dates back to 120 million years, to the early Cretaceous, a time when Fukuisaurus and other hadrosaurs areknown to have been abundant.

Wednesday, March 21, 2007

Burrowing dinosaurs!

Amazing new discovery reported on New Scientist's website today:


Evidence for a species of BURROWING dinosaur. The coyote-sized animals were hipsilophodonts, closely related to the hadrosaurs (my personal favorite class of dinos), and the fossils were discovered by David Varricchio of Montana State University in Bozeman. It appears that an adult and two juveniles were in the burrow together...does anyone else smell parental care? Its name is Oryctodromeus cubicularis, which means "digging runner of the lair."

Excerpt from the news story:
The bones were inside a twisting, worm-like deposit of sandstone that passed through three distinct layers of rock.
Varricchio says the sandstone formed 95 million years ago when sand washed into a burrow measuring more than 2 metres in length, 30 centimetres in width, and nearly 40 cm high. The dinosaurs inside had apparently already died of unknown causes.

Judging from the illustration, it looks like the skeleton was amazingly complete, also:

Just another illustration of how much there is left to learn (and how much we will probably never even guess) about the ecology and diversity of dinosaurs...awesome find!

Reference:
Varricchio, David, Martin, Anthony, and Katsuro, Yoshihiro. First trace and body fossil evidence of a burrowing, denning dinosaur.
Proceedings of the Royal Society B (DOI: 10.1098/rspb.2006.0443)

Saturday, March 17, 2007

Polygyny Threshold

It doesn't take a scientist to figure out one of the most basic principles about relationships: males and females often have very different mindsets. Any survey of humans could show this, but the principle is universal, with the "battle of the sexes" being fought over and over everywhere from colonies of marine invertebrates to you local singles bar.

The main idea:
1. Males are capable of fertilizing many females, and so it is to their advantage to seek as many mates as possible.
2. Females are limited in their reproductive capabilities and invest more time and energy into offspring, so they are more 'careful' about critical resources, including mate selection.

But, it could be argued, there is a way to make everyone happy! In polygynous systems, several females share a single male mate. This is a widespread mating system, and is even found in up to 2/3 of traditional human societies. Boy gets many girls, many girls get boy's resources, everyone wins, right?

Obviously it cannot be this simple. If polygyny is that universally advantageous, why would any animal be monogamous? There are many examples of strong male-female pair bonds in nature, most classically avians: 90% of bird species are monogamous. Gulls, with a "divorce rate" of 0.3%, put humans and their approximately 50% rate of failed marriages to shame.


So what determines whether a species is polygynous or monogamous? There are many factors, but a particularly instructive case is that of hoary marmots, (Marmota caligota).
Marmots are Northwestern mountain animals, living in alpine meadows from Idaho and Washington up to Alaska. This is not a kind environment, and scrabbling out an existence on the cold mountainsides obviously involves many resource limitations for the animals. They are known to be very territorial, and males will aggressively defend their home ranges.


Those home ranges are the key for the principle of polygyny thresholds. This is basically a measure of how "bad" a territory must get before a female decides that she'd rather be someone's second mate than have a mate all to herself. As long as territory quality is good and plentiful, monogamy will dominate, but if it gets to the point that all the single males have poor territories, a female will choose to share a territory and mate with another female, effectively switching to polygyny. In populations where there is little difference in fitness between being the 1st or 2nd (or 3rd, etc) mate, you will see polygyny more often. This means that you can have a single population of marmots in which both monogamy and polygyny occurs, with high-quality males having many mates and males with pooer territories only being able to support a single one.
That, my friends, is a polygyny threshold. Draw human analogies at your own risk/entertainment.

Friday, March 16, 2007

New species: Bornean Clouded Leopard!

Yesterday the WWF issued a press release announcing that a new species of big cat has been declared, the Bornean Clouded Leopard (Neofelis diardi). It is really rare to find previously undescribed mammal species, this is a HUGE deal in the zoology community. Genetic analysis at the National Cancer Institute has concluded that the genetic differences between this and 'regular' Clouded Leopards (Neofelis nebulosa) are at least as large as those separating jaguars, lions, tigers, etc.

The 'new' species (which is not actually new, persay, the populations have been known about for quite a while but have only now been classified as a separate species) have a darker pelage, with spots in their "cloud" markings and a double dorsal stripe. Also, there is distinct geographic separation between the two species. Only N. diardi inhabits the Malay Peninsula, specifically the Indonesian islands of Borneo and Sumatra, while N. nebulosa lives on the mainland of Southeast Asia.

While there are estimated to be 5,000-11,000 mainland Clouded Leopards, the Bornean species is though to number 3,000-7,000, although it is very difficult to get accurate population information for these elusive species. The region of Borneo where this cat is found has yielded discoveries of 52 new species in just the last twelve months!

Clouded Leopards are ranked as an Appendix I endangered species by CITES, and as Vulnerable by IUCN. Hunting these cats is forbidden in most of its range, but these regulations are rarely enforced. It appears that attention drawn by this new discovery will greatly benefit conservation efforts, however: last month three Bornean governments: Brunei Darussalam, Indonesia and Malaysia--signed an historic Declaration commiting to conserve the region known as the "Heart of Borneo"

You can find out more about Clouded Leopards and conservation efforts to protect them at the The Clouded Leopard Project website.

A couple of interesting leopard facts:
~They have the largest canine teeth of any cat, relative to total body size.
~They are considered to be the "most arboreal" of all big cat species.

Further References:
Buckley-Beason et al., (2006). Molecular Evidence for Species-Level Distinctions in Clouded Leopards. Current Biology 16(23): 2371-2376.

Kitchener et al. (2006). Geographical Variation in the Clouded Leopard, Neofelis nebulosa, Reveals Two Species. Current Biology 16(23): 2377-2383.

Sunday, March 11, 2007

Familial Down Syndrome

Chromosomal abnormalities are the main cause of birth defects afflicting tens of thousands of infants every year. The numbers are pretty scary, about 20% of all conceptions result in spontaneous abortions (usually before the mother knew she was pregnant), and about half of those are due to a chromosomal abnormality. Of all conceptions that do show those abnormalities, 98.4% are aborted, 1% are stillborn, and 0.6% make it to birth alive.

When you consider that between 25 and 30 thousand babies are born with these abnormalities each year in the U.S., that means that there are over a million conceptions with abnormal chromosome configurations! The cellular processes controlling cell division, fertilization, and development are very specific, and the slightest misstep has extremely serious consequences.

The most well-known chromosomal abnormality is Trisomy 21, also called Down Syndrome. Individuals with this disorder have three copies of chromosome 21, instead of the usual two, and this is estimated to be the cause of 1/4 of ALL miscarriages. This results from a nondisjunction when the chromosomes separate in meiosis. Either the sperm or the egg (almost always the egg) ends up with both copies of the chromosomes which were supposed to be divided between the two daughter cells, and after fertilization by the sperm, which has its own Chromsome 21. the baby then has three, giving it a total chromosome count of 47, as opposed to the 46 found in normal humans, resulting in the characteristic abnormalities of the syndrome: epicanthal folds (the politically incorrect reason the disorder used to be called "Mongoloid idiocy"), underdeveloped secondary sex characters, depresssed immune system, heart trouble, simian fold on the palms, and various other health problems resulting in shortened life expectancy.

This is how the vast majority of Down Syndrome cases can be explained. There is, however, a different mechanism that can produce exactly the same disorder. Called "Familial Down Syndrome", it results from a translocation of part of Chromosome 21 onto Chromosome 14. Basically, part of 21 breaks off and attaches itself to 14, but it is a big enough chunk that it retains most of the genes and can function well enough to substitute for the whole chromosome.

So you have a cell with a good 21, and two 14's, one of which has a second 21 latched into it. What happens when the cell divides (goes through meiosis) to make gametes? It is supposed to dole out its chromosomes equally to each daughter cell, but this configuration can't be separated correctly. As a result, you get four kinds of gametes: normal, one with only 14, one with only the 14/21 hybrid, one with a 21 and the 14/21.

Obviously this is a mess, and it gets worse after fertilization. The results are shown below. The blue chromosomes are 21, the pink ones are 14. There are four possible outcomes of a fertilization: you get a normal child, a child that looks normal but carries the mutation, a nonviable zygote (all autosomal monosomies in humans are fatal), or a child with Down Syndrome, which has a 45% chance of surviving to its first birthday.

This fascinating mechanism is the cause of about 3-5% of Down cases, and is an example of the complexities involved in chromosome regulation during development.