Science Tidbits for July 17, 2012


























Lord Howe Island Stick Insect hatching from Zoos Victoria on Vimeo.








And if you are on Twitter, Follow me!


Science Tidbits for July 13, 2012

Its Friday the Thirteenth… I wonder what Neil would say.












Medical science











Wonderful photos of the wee animicules of the ocean







Antarctic moss finds an unlikely nutrient source. Ancient penguin poop.


Environmental science
















Science tidbits for July 2, 2012





Quoting wikipedia’s article on Feathers > Evolutionary stages


  1. Single filament
  2. Multiple filaments joined at their base
  3. Multiple filaments joined at their base to a central filament
  4. Multiple filaments along the length of a central filament
  5. Multiple filaments arising from the edge of a membranous structure
  7. Pennaceous feather with an asymmetrical rachis
  8. Undifferentiated vane with central rachis














Edited to add this video

Miscelania linkelist

Mass extinctions can have subtle effects on evolution.

Science Tidbits for June 25, 2012

First things first, the Houston Museum of Natural History (@HMNS) is running a fundraiser, calling on donors to “adopt” a prehistoric pet. Depending on the donation, you can adopt a different animal and can receive a variety of thank you gifts including drawings or replicas of your pet, certificates, or tickets to the museum, but most importantly, the knowledge that you are helping a home of public learning and science advocacy. If I get the job I’m hoping for, I might just adopt a triceratops. I hope it stays small. I hear they can get rather big…

Now on with the Science!

For the last week, I have been posting “science tidbits” as my own take on teaching tidbits. The idea behind a “tidbit” is that you can drop it right into a lesson plan in order to enrich the lesson, make it more relevant to students, or to tie it into current events. I try to mix in ideas about how to use them in the classroom and if you have an idea, please share it in the comments.

When you think of sharks, you usually think of fast predators, moving just under the waves, carefully stalking its prey… The Greenland shark fits all of those ideas except for “fast.” Scientists knew that the greenland shark ate seals from examination of stomach contents, but figured that they scavenged dead seals. Seals are really fast, so a shark that swims at a speed slower than a mile per hour is an unlikely predator. There is a new hypothesis, though…

“Arctic seals sleep in water to avoid predation by polar bears (Ursus maritimus), which may leave them vulnerable to this cryptic slow-swimming predator,” wrote the authors of a recent study on Greenland sharks’ speed, published in the Journal of Experimental Marine Biology and Ecology.

Where does this fit into a lesson? Any discussion of a food web in the Arctic would include polar bears as an apex predator, and adding the greenland shark into the mix stresses the diversity of the environment and the importance of what happens beneath the ice. You could also describe the shark, where it is found, how fast (or slow) it is, and ask students to come up with ideas about what an animal like this would eat.

Beyond that, the greenland shark isn’t the best known or best studied of sharks, which can make it an interesting creature for an “internet” scavenger hunt, where students hunt for information about the slowest shark, or smallest deer or a venomous mammal, or a good topic for a short group presentation on lesser known organisms.

Making the tidbits again, a chance to talk about zoonotic diseases. Koala bears are one of the cutest animals on the planet. Who doesn’t love them?

Wild koala numbers started dropping last decade, and researchers asked the obvious question, why? (Brainstorm opportunity) It turns out that there are three different organisms attacking koalas, one of which is a retrovirus that is attacking their immune system. The other two are different strains of the Chlamydia, Chlamydia pecorum and Chlamydia pneumoniae, and at least the C. pneumoniae strain can infect humans.

Unfortunately, C. pneumoniae can be transmitted to humans. Koala’s incredible cuteness works on the disease’s behalf. People enjoy picking them up, but like many tree-dwelling animals, koalas don’t much care where they urinate. If an infected koala urinates on a person, they can possibly transmit the strain of chlamydia to the human.

It is frighteningly easy to pick up diseases from animals, wild or domestic, so being aware of these risks is a good idea. Another opportunity for discussion comes in with what people can do to help the koalas. There is a vaccine that appears to work for the retrovirus, but the only treatment for chlamydia sp. is antibiotics. This can quickly lead to a secondary discussion of antibiotic resistance, as there is nothing to prevent reinfection or to prevent resistance from arising. Since humans can be infected with C. pneumoniae, it would be a very bad thing to encourage the bacteria to develop resistance in the wild as it would limit which antibiotics could be used to treat infected humans. This closely mirrors discussions of the use of antibiotics in livestock.

The opportunities for dropping this topic into lessons about infectious diseases, antibiotic resistance, ecology… are endless. Its a good topic for high school on, with advanced undergraduate and any graduate student delving deeper, perhaps presenting short talks on the topic.

The concept of a “living fossil” is a messy one. It suggests that an organism is completely changeless over millions of years, which can be very misleading. Many so called living fossils closely resemble their ancient relatives, while others have undergone morphological changes. The coelacanth isn’t just a single species of lobe finned fish, but is a large group of both modern and extinct species with many morphological differences and falls into several species. Beyond that, they are no longer thought to be the group most likely to have given rise to land dwelling tetrapods.

This isn’t just a good discussion topic, but can be a good topic for small group discussions in high school and undergraduate courses. Give students a list of misconceptions about evolution (a very long list can be found here) and have them examine and present the science behind them. This has great risks and great rewards. Students teaching each other can be one of the most effective ways to learn, and breaking down bad ideas is an important step in the process of learning evidence based science. Remember what Chuck said,


-Charles Darwin

Giving students the tools to replace false facts with true ones is vital in teaching topics that are controversial in culture, but not among scientists. The talk origins database is one of the best ones you can offer for evolution, with Skeptical Science a great one for climate change (from real skeptics, not ones using the title for PR purposes). However, if you get a student that wants to present personal beliefs instead of what the evidence says, or if you pick a topic that is too broad or too narrow, it can end up as a mess.

The other risk/landmine is that you absolutely should avoid discussing religion in a public school classroom, and if you are teaching at a religiously affiliated private college (or even a public institution), you need to be careful to make sure that your administration backs you up. Creationist organisations can put a tremendous amount of pressure on a college and the list of educators that have lost their positions due to the controversy that they can bring to bear is very long and grows longer every year. Be careful to stay within the boundaries of science. No matter what you think of NOMA personally, it is a good guideline for the classroom. If you limit discussion topics to things like living fossils, missing links, the existence of transitional fossils, or why gaps in the fossil record are not only expected but are not a problem for evolution, you should be fine. If you need advice, talk to the NCSE (link above).

If you are using the previous tidbit, or are sending students to use the internet for sources, this is a good read for you and for more advanced students. Lots of material on the internet is accurate, but lots of it is simply junk. If students are doing a presentation, go over their sources with them, and look to make sure that they are reliable.

And one for the teachers, when you are teaching a difficult concept, one that students typically respond to by saying that they will never use it… you need to respond immediately with real world uses, or defuse it before it starts. That can be easy for me. Not understanding evolution kills people via a bad understanding of antibiotic resistance, genetic and evolutionary causes of medical problems, etc. Students can grasp the importance of medicine, poisons, venoms, cancer. But not everything is so easy. Tidbits help a lot. That is the purpose of sharing them and always looking for new ones.

Teach on.

New Dimetrodon fossil

Dimetrodons were one of my favorite dinosaurs when I was a kid, even if I didn’t know that they weren’t actually dinos. As a group, they are considered synapsids like us, making modern mammals like us their very distant descendants, by 280-265 million years.

These guys are likely to be in the news in the next several days due to a find in Texas the by Houston Museum of Natural Science of a nearly complete articulated skeleton of Dimetrodon giganhomogenes.

Dimetrodon_gigashomogenesCrikey, but he’s a pretty fellow! (artist’s conception, credit DiBgd)

Keep in mind that complete skeletons are themselves rare, but being able to observe articulation is especially neat, as we can actually see how the joints fit against each other.

You can see just how excited Dr. Bakker is at this discovery in this video. What a great addition to the collection at HMNS.

Rare, Nearly Complete Dimetrodon Found! [HMNS Paleontology] from HMNS on Vimeo.

Ideas for lessons?

Elementary school: Lots of kids will know what a Dimetrodon is immediately, but many won’t know that they weren’t dinosaurs. You can talk about why these aren’t quite dinosaurs. Synapsids have a hole in their skull just behind their eye socket that a jaw muscle goes through. You can ask your students if they knew that they had the same feature. Synapsids also have teeth with different shapes, while reptiles including dinosaurs typically have teeth that are fairly similar throughout. Again, your students have this feature, too, with incisors, molars and canine teeth. Finally, synapsids have legs that are perpendicular to their bodies, like crocodiles, while dinosaurs have legs that are in line with their bodies. We don’t share all of the features of Dimetrodon, but these details can further interest children in learning about science. There are other differences, but this should be enough to get you started on a very fun lesson.

You can pick up a plastic model of one of these anywhere plastic dinos are sold, so a visual aid won’t set you back too badly.

Another exercise would be to ask the students to draw what they think scientists look like. Dr. Bakker is an example of a working scientist that isn’t wearing a lab coat, doesn’t have white hair going in every direction, etc. Make sure that you include some other scientists, and don’t leave out women scientists!

High school: This makes for a good science in the news moment, and again, a plastic toy makes a good visual aid. This also fits into lessons on the history of the earth as an example of life in the Permian period, and if you are in an area of the country that encourages teaching evolution as part of the science standards, these are early ancestors to mammals, even though they are very reptile like.

College: I often start class with an organism of the day, and even though it takes a few minutes out of every lecture, it helps students understand that science is an ongoing process and that we are learning more about life every day.

Furthermore, this can be an examination of cladistics and common ancestry. Review the wikipedia page here, and you can take your class beyond your textbook to examine these topics. Pictures of Dimetrodon and human skulls would be useful in comparing cranial features.

Have fun, and teach on.