Narwhals are Magic.
Now with proof! Secrets of the narwhal’s tusk have recently been revealed in research headed by Martin Nweeia, a practicing dentist and clinical instructor at the Harvard School of Dental Medicine, who just happens to also be a member of the Vertebrate Zoology Department of the Smithsonian’s National Museum of Natural History. With a team of researchers/coauthors, including Jim Mead, Vertebrate Zoology Curator Emeritus and Charlie Potter, Marine Mammals Collection Manager, Nweeia just published a paper in the journal The Anatomical Record about the discovery of neural pathways that run from the narwhal’s tusk to its brain. The arctic whale’s unicorn-like tusk acts as a sensor, specifically detecting variations in water salinity. Read more on the Smithsonian Science blog, or see the original article at Anatomical Record (You might want to head to your local library to see if they have access since it’s behind a paywall).
There are some pretty great images of narwhal’s over on the Biodiversity Heritage Library’s Flickr page, too.
Eat Your Tardigrades or You Don’t Get Dessert!
You know this little guy, right? It’s the mighty tardigrade, as featured in the new Cosmos. Tardigrades, also known as water bears, also known as FREAKIN’ MOSS PIGLETS, are microscopic eight-legged animals that can withstand temperatures from near absolute zero to boiling water, absorb extreme doses of radiation, go without food or water for ten years, and even survive the vacuum of space. They can even be completely dried out and ride on the wind to a new home, where they rehydrate and go about their tardibusiness. Tardigrade rain, folks.
In other words, they are BAMFs (bad-ass microfauna).
Oh, and you’ve probably eaten them. Thanks to Meg Lowman, I found out that these water-dwelling super-critters live not only on wild mosses and wet plants, but on grocery store produce like lettuce and spinach. Do you think that a mere rinse or shake under the faucet (or even cooking) is enough to dislodge a radiation-eating space pig? Ha! Not by a long shot, according to Lowman.
So yeah… trying to go strictly vegetarian? You’ve almost certainly eaten some tardigrades. Sorry. Don’t worry, though. They’re totally harmless. I like to imagine that when I eat them, I absorb their power, and become a little bit mightier.
New motto: For strength, eat your vegetables and eat your tardigrades.
Meg Lowman has more about your local tardigrade friends. Also check out Lowman’s awesome research project that helps wheelchair-bound students climb to the top of the forest canopy where they help study tardigrade biodiversity. Science is for everyone!
Plant These To Help Save Bees: 21 Bee-Friendly Plants. Learn more here!
Hannah Rosengren 2013
"Hey, evolution, what are you doing for Halloween?"
"Well, I made this moth, and then I dressed it up like two flies feeding on a big wet pile of bird crap."
"I even made it smell like bird crap.”
"Isn’t it awesome?"
"Why couldn’t you just do ‘sexy cat’ like everyone else?"
A kiwi has the largest egg relative to its body size of any bird - it’s about 20-25% of the animal’s entire weight. That’s like if I gave birth to a 35lb baby.
Image from the Hall of Birds at The Field Museum.
Sexual Cannibalism | Wild Sex Ep 1
This is a brilliant series about ‘wild sex’ or to put the more scientific term ‘Behavioural Ecology’ - the mating habits of the animal kingdom. It is not only informative, but very funny and I would highly recommend it!
The plight of the honeybees.
Bee photos by John Kimbler [flickr]
TheFrogMan wins the Hank Green’s Opinion award for “Best at Tumblr”
Screech Owls and Blind Snakes, an Unlikely Mutualism
by Andrew Durso
In the 1970s and 80s, a pair of biologists at Baylor University in Waco, Texas, Fred Gehlbach and Robert Baldridge, were studying screech owl nesting ecology. These small owls nest in tree cavities and eat a variety of small animals, from insects to mice. Like most raptorial birds, Eastern Screech Owls usually kill their prey before bringing it home to feed to their nestlings.
Gehlbach and Baldridge observed some of the screech owls in their study carrying live Texas Blindsnakes (Rena [formerly Leptotyphlops] dulcis) to their nests in experimental nest boxes like those used by wood ducks and bluebirds. When they checked the nests the next day, they found, to their surprise, between one and fifteen live blindsnakes living among the owl chicks in fourteen different nests! In some cases, the snakes lived with the baby owls for at least a week! Many of the blindsnakes bore scars from adult owl beaks, but few had been killed.
f you’re not familiar with blindsnakes (aka scolecophidians), don’t worry; few people are. There are about 400 species of these ‘seriously strange serpents’, as Darren Naish calls them over at TetZoo, distributed chiefly in the world’s tropical regions (the Texas Blindsnake is one of the few temperate exceptions). Most have small eyes (or none at all, as their name suggests), smooth round scales, and eat invertebrates. Their jaw architecture is entirely unique: their jaws act like little scoops to effectively shovel ant and termite larvae and pupae into their mouths.
How does this help baby screech owls? Gehlbach and Baldridge wanted to find out, so they measured the diversity and abundance of invertebrates in the owl nests with and without live blindsnakes, as well as the health and survival of the baby owls (which they were already measuring). They found that nests with blindsnakes had significantly fewer mites, insects, and arachnids, and that baby owls from these nests were 25% more likely to survive and grew as much as 50% faster…
(read more: Life is Short, But Snakes Are Long)
Slater Museum: Featured Creature - 8 Feb 2013
Rock Pocket Mouse (Chaetodipus intermedius)
This adorable little rodent is a native of the American Southwest and lives rocky desert environments throughout Arizona and New Mexico. But this modest mouse is far more than just a cute critter. The Rock Pocket Mouse is also a poster-child for natural selection!
This seemingly innocuous rodent has a very special color polymorphism (i.e. variations in coat color) that has earned it a prominent place among biology and evolution text books world-wide. Ever since these differences in coat color were first described in the 80s, scientists have been fascinated by the Rock Pocket Mouse. Sure, plenty of animals show interesting differences in coat or plumage coloration - finches vary from orange to red, owls in the east tend to be redder than their cousins in the west, some Jaguars are born with pitch-black pelts - so what’s so special about this dinky mouse?
While melanism in big cats is a genetic mutation and redness in finches is diet-dependent, the color polymorphisms in Rock Pocket Mice appear to correlate with habitat. Naturalists in the 80s and 90s first described this correlation, noting that light-colored subspecies tend to mostly live in areas with light-colored sandstone and rock, while dark-colored subspecies thrived mostly in areas with dark, volcanic rock. Scientists found that mice living on mismatched substrates (light coats on dark rock and vice versa) were more likely to be captured by predators like hawks and owls, thus selecting for specific coat colors in specific locations.
Before the age of genetic research, evidence for Darwin’s theory of evolution was primarily based in phenotypic, fitness-related traits - the genetic aspect of Darwin’s theory was still largely unsupported. It wasn’t until 2003 that researchers at the University of Arizona determined the genetic basis for this phenomenon, thus connecting phenotype (the fur color) with genotype (the genes) and providing extremely robust evidence for evolution by natural selection.
Today, this example of a naturally-selected color polymorphism is in nearly every evolution text-book and is cited by researchers around the world.
And you thought it was just another mystery mouse!
To learn more about this elegant study check out their 2003 paper.
Congrats to leuchtturm for being the first to notice that one of our specimens is missing a tail!
A Phylogenetic Blueprint for the Modern Whale
The emergence of Cetacea in the Paleogene represents one of the most profound macroevolutionary transitions within Mammalia. The move from a terrestrial habitat to a committed aquatic lifestyle engendered wholesale changes in anatomy, physiology, and behavior.
The results of this remarkable transformation are extant whales that include the largest, biggest brained, fastest swimming, loudest, deepest diving mammals, some of which can detect prey with a sophisticated echolocation system (Odontoceti – toothed whales), and others that batch feed using racks of baleen (Mysticeti – baleen whales).
A broad-scale reconstruction of the evolutionary remodeling that culminated in extant cetaceans has not yet been based on integration of genomic and paleontological information. Here, we first place Cetacea relative to extant mammalian diversity, and assess the distribution of support among molecular datasets for relationships within Artiodactyla (even-toed ungulates, including Cetacea). We then merge trees derived from three large concatenations of molecular and fossil data to yield a composite hypothesis that encompasses many critical events in the evolutionary history of Cetacea. By combining diverse evidence, we infer a phylogenetic blueprint that outlines the stepwise evolutionary development of modern whales.
This hypothesis represents a starting point for more detailed, comprehensive phylogenetic reconstructions in the future, and also highlights the synergistic interaction between modern (genomic) and traditional (morphological + paleontological) approaches that ultimately must be exploited to provide a rich understanding of evolutionary history across the entire tree of Life.
Gatesy J, Geisler JH, Chang J, Buell C, Berta A, Meredith RW, Springer MS, McGowen MR. 2013. A phylogenetic blueprint for a modern whale. Mol Phylogenet Evol. 66 (2), 479–506: doi: 10.1016/j.ympev.2012.10.012.