Thursday, February 25, 2010

When you make strange noises here, seabirds...

Check out the nose on that Petrel. I'll have to re-watch this episode because for the life of me I can't remember the secret behind the tube.

Monday, February 22, 2010

Pass the earthworm, please.

Pollenia rudis is known as the attic or cluster fly because of its tendency to overwinter en masse in human structures. P. rudis belongs to the family Calliphoridae, and most calliphorids feed on carrion (or occasionally living flesh) as larvae. {that's not completely true, some Australian Calliphoridae:Rhiniiae are myrmecophiles}  Taking the road less traveled, P. rudis larvae seek out earthworms. For the first two instars, they feed internally, although apparently larvae may leave an unsuitable host and find a new worm to consume. Third instar maggots are larger and have been known to feed externally on worms. How this life strategy was adopted from feeding on carrion seems to be a big mystery. Gradualist (classic) views of evolution are often hard-pressed to answer these questions, which is why I'm a big fan of hopeful monsters (think bulldog or chihuahua) and punctuated equilibrium. These ideas theoretically allow for a small number of individuals to experience a rapid change in form and function....which makes it easier to understand increasingly common situations such as this lizard population which evolved new digestive tract valves in less than 40 years.


















P. rudis image from: http://bugguide.net/node/view/362910/bgimage

Friday, February 19, 2010

Friday Troglobite

I'm waiting on permission to post some really cool beetles which only live in caves in Texas, but until that works out I'll stick with bats. This one is eating a frog.


















Image from:
http://www.sciencedaily.com/releases/2006/06/060619235450.htm

Thursday, February 18, 2010

What's going on here?













Photo by Alex Wild.

The business end of a female Northern Walkingstick (Diapheromera fermorata) is well equipped to disperse eggs- some tropical species have modified their segments into a biological catapult...looking at the picture I wouldn't be surprised if these did something similar.

Monday, February 15, 2010

Need dung? Go to the source.

Canthon aff. quadriguttatus (still not sure what the aff. is...) is a fairly plain looking dung beetle. It has a little color to it, but otherwise it is unremarkable.


















Until you learn about its behavior. It turns out that this is one of the dung beetles which has cut the search for dung out of its life history and gone directly to the source. For this species, that means hanging out around these guys.











Specifically, right around here:


















If this seems peculiar, consider that in India a related species of dung beetle does the same thing to humans. And... it doesn't always wait for the resource to make its exit. Even stranger may be Zonocopris gibbicollis, a dung beetle which plays the same trick on giant land snails.

Original papers and pictures from:
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2008000600003

Saturday, February 13, 2010

Corynorhinus townsendii virginianus

I haven't posted another troglobite in too long. To make up for this, here is the official state bat of Virginia. For a long time scientists thought that bats were the closest living relatives to primates...but now we're pretty sure that position belongs to tree shrews.

Life's Ultimate Architect

This is the finale to "Home Making" from David Attenborough's The Trials of Life. As with all of Attenborough's final examples, it's nearly unbelievable. I'm speechless.

Monday, February 8, 2010

"This is science, not Avatar"

There's something about dinosaurs lately. For a long time we had no idea what dinosaurs would have looked like alive. For most species, we still don't. Finally, scientists have published what they believe is the most accurate representation of the color and appearance of Sinosauropteryx, the first dinosaur (not yet a bird) to be discovered with feathers. This work was possible because pigment containing structures in the feathers, known as melanosomes, survived fossilized. So this is probably what the beast looked like:












Too cool. Full article here:
http://www.nytimes.com/2010/02/05/science/05dino.html?ref=science

Sunday, February 7, 2010

One more falsehood from high school biology.

The video below is the opening to the last episode of the Planet Earth series. The first time I saw who was paddling that canoe around I was stunned. Just a few years ago I was being taught that humans are the only tool using animals. It turns out that there are at least a dozen bird species which exhibit complex tool use. Even some invertebrates use tools (maybe).

Monday, February 1, 2010

Tree Foraminifera

Notodendrodes antarctikos, is a single celled amoeba-like creature that lives in sediment on the floor of the Arctic Ocean. Some scientists believe that Foraminifera may represent a 'missing link' between naked cells and shelled protists (tiny tiny animal-like creatures). This particular Foraminifera is named because its shape is strongly convergent with a tree, it has root-like projections into the sediment which absorb dissolved nutrients, and intricate branches rising a few millimeters above the sea floor which capture suspended food such as algae. Its closest living relative is found in the tree form and the more 'traditional' sphere form.

I stumbled across these while watching "Encounters at the End of the World" which is available for instant view on Netflix. By far one of my favorite documentaries. In it I learned that N. antarctikos has been central to the debate on intelligence. These single cells apparently pick out only particular size grains in the building of their shells, which makes them eligible for all definitions of 'biological intelligence' proposed.

Darwin apparently had this to say:
"The case of the three species of protozoan (I forget the names) which apparently select differently sized grains of sand, etc., is almost the most wonderful fact I ever heard of. One cannot believe that they have mental power enough to do so, and how any structure or kind of viscidity can lead to this result passes all understanding."

 The picture below (this is one cell...) comes from Dr. Sam Bowser (who was in the film) courtesy of Shawn Haper.















Image from:
http://icelabyrinth.blogspot.com/