Preparing for Rabbit Dissection

References

Linn (2000) has a good overview of general rabbit biology and the internal organs in Rabbits: Biology (pdf).

For lots of detail on how to dissect a rabbit try Bensley’s Practical Anatomy of the Rabbit (free on Google Books)

AnimalLearn.org has a good list of free and for fee online dissections of various organisms. No rabbits as of this moment though.

Teaching Organic Farming

Teaching Organic Farming and Gardening
UCSC’s Teaching Organic Farming and Gardening

One of these days I’d like to put in a garden at school. Or maybe a few gardens. An indoor hydroponic system would be nice for the winter months, as would a greenhouse. However, the easiest thing to start with might be putting in some raised beds. To this end, the University of Santa Cruz’s Center for Agroecology and Sustainable Food Systems has detailed information in their Teaching Organic Farming & Gardening: Resources for Instructors manual.

Mr. Sansone.

Understanding the Extinction of the Dinosaurs (and the Survival of Mammals)

This neat paper (Robertson et al., 2013) in the Journal of Geophysical Research makes an interesting attempt to explain the pattern of extinctions that occurred at the end of the Cretaceous: why most of the dinosaurs died out, and why ocean organisms were more severely affected than freshwater organisms by the long winter after the asteroid impact.

The flow chart explains:

Diagram of contrasts between freshwater and marine environments for factors potentially causing extinction in aquatic environments after the Chicxulub impact. (Image and caption from Robertson et al., 2013).
Diagram of contrasts between freshwater and marine environments for factors potentially causing extinction in aquatic environments after the Chicxulub impact. (Image and caption from Robertson et al., 2013).

They also include an interesting figure showing how long an organism might survive based on how large it is, which I may be able to use in pre-Calculus when we’re discussing log scales and linearizing equations.

Allometric relationship between body size and time to death by starvation for multicellular poikilotherms in the absence of food (red, drawn from the equation of Peters [1983, p. 42]). Names of various types of organisms are shown as an indication of body size. Image and caption from Robertson et al., 2013.
Allometric relationship between body size and time to death by starvation for multicellular poikilotherms in the absence of food (red, drawn from the equation of Peters [1983, p. 42]). Names of various types of organisms are shown as an indication of body size. (Image and caption from Robertson et al., 2013.)

The article is written well enough that an interested high school biology student should be able to decipher (and present) it.

Crayfish: Charismatic Mesofauna

This year, the creek is teeming with crayfish, especially compared to last year during the drought when the creek dried up and the crustaceans were hard to find. I had five students out collecting organisms on Wednesday, and they came back with ten crayfish ranging in size from a couple centimeters long, to one that was about 12 centimeters from claws to tail.

Crayfish in a jar.
Crayfish in a jar. Seen through stereoscope. Magnification unknown.

I was just looking at one of the pictures I took and realized that I did not know what species it belonged to. I’ll be having students do reports on individual species for biology next year, and I’d be very surprised if someone did not choose crayfish. They’re so many of them and, as my students from Wednesday will attest, they’re just so charismatic. While I’ve not looked into it much myself, the Crayfish & Lobster Taxonomy Browser seems a decent place to start researching.

3d Molecule Viewer

An excellent 3d viewer for molecules.

An excellent 3d molecule viewer. (The actual app has a lot smoother animations than this.)
An excellent 3d molecule viewer.

In addition to the existing molecules, you can import any number of others if you can find them in one of the right formats (PDB, SDF or MOL molecule definitions): the ligand.info: Small Molecule Meta Database is a good source for SDFs.

Johnson’s Shut Ins

Exploring the natural water works at the Johnson's Shut Ins.
Exploring the natural water works at the Johnson’s Shut Ins.

First off, the Shut Ins are narrower constrictions in the river valley formed when stream flows into an area of harder rock. The hard rock, in this case an old (1.5 billion year old) rhyolite flow, is relatively resistant to erosion, especially the side-to-side erosion that flattens out little flood plains as small rivers meander through the foothills of old mountains like the Ozarks. So the stream only erodes downward through the hard rocks creating a narrow gorge. As they say here: the river’s “Shut In”.

When I told people that I wanted to do a few camping trips this summer, the number one recommendation was the Shut Ins. And I can see why. I took my boys and they had an awesome time.

“It’s like the City Museum. Only real.”
— Overheard at Johnson’s Shut Ins

The Shut Ins are a maze of narrow channels, the old igneous rocks carved smooth by the water and its gravelly bed load over millions of years. A great place for kids to traipse through and explore. I bit like a water-park version of the City Museum in St. Louis.

Rushing water in a shallow channel leads to a deeper pool.
Rushing water in a shallow channel leads to a deeper pool.
Looking down from the cliffs above the Shut Ins, the sets of linear joints in the rocks are quite clear.
Looking down from the cliffs above the Shut Ins, the sets of linear joints in the rocks are quite clear.

The pattern of the channels is largely determined by the jointing in the rocks, because the joints offer easier pathways for water and erosion. There are at least two obvious sets of joints in the rocks, but I would not be surprised if they overlay other patterns given how old the rocks are. As it is, however, the erosion through the joints creates lots of neat little chutes.

Looking along a narrow eroded joint.
Looking along a narrow eroded joint.

Since the Shut Ins are only a couple hours away from St. Louis, they’re a pretty popular tourist attraction.

Population density is high.
Population density is high.

There’s a lot of science that can be done here, however, that would make this a good location for an immersion trip, especially since Elephant Hills State Park (with wonderful spheroidal weathering) is close by. The camping facilities at the Shut Ins State Park are new and quite nice, having been completely rebuilt with some of the $100 million in settlement money from the Ameren power company after the park was flooded by their Taum Sauk reservoir breach in 2005.

The path of the wave from the Taum Sauk reservoir breach created a debris field with huge boulders, and demolished the original Johnson's Shut Ins campground. The Shut Ins themselves are downstream to the right.
The path of the wave from the Taum Sauk reservoir breach created a debris field with huge boulders, and demolished the original Johnson’s Shut Ins campground. The Shut Ins themselves are downstream to the right.

It’s certainly worth the visit.

As the stream exits the Shut Ins it has dredged some excellent swimming pools.
As the stream exits the Shut Ins it has dredged some excellent swimming pools.