Science Tidbits for June 29, 2012

How cool are worms? Really cool. Worms are freaking neat. Annelids (the phylum including earthworms, leeches and polychaetes) are just flat out odd sometimes, and odd makes for teachable concepts.

Zombie worms are polycheates that live in the deep ocean, and have a very odd way of eating.

They don’t, not exactly.

They don’t have mouths. They don’t have stomachs, intestines or anuses either, and yet, they eat the bones of dead whales, and are called bone eating worms or osedax, which means bone eating in Latin.

They use a branching anchor with rootlike structures, covered in microvilli, to secrete acid, which breaks down the calcium structure, liberating fats, which are absorbed and then digested by bacteria living in the tissues of the worm. And zombie worms aren’t even the most grossly named of these critters. Behold the bone eating snot flower worm!

So they don’t eat, but do break down bone and absorb food from their surroundings.

It sounds a bit like a fungus, actually. And this can be a great chance for you to talk about how what a normal defining characteristic of a kingdom (ingesting food for Animalia, photosynthesis for Plantae) are sometimes abandoned, but the organism never hops to another kingdom. A ghost orchid that doesn’t photosynthesize is still a plant, existing as a parasite on fungi underground, only poking up to flower on rare occasion. Students often want to think of non-photosynthesizing plants as fungi, and might want to do the same with bone eating worms, but they still have all the other features of their kingdoms. The osedax still doesn’t have cell walls or mycorrhizae like a fungus. It still has closer genetic ties to other polychaetes and annelids than to anything else. The ghost orchid still has cellulose cell walls instead of chitin. It may not have chloroplasts, but it still is a plant. Great chance to have a lesson on phylogenetic trees.

Another topic you can bring up is the use it or lose it concept. Osedax don’t use a digestive tract and don’t need one. The genes for a digestive tract are turned off and over the millions of years since they evolved, the genes probably have become mutated into a non-functional state. It was once assumed that once you go down this tract, you can’t go back, but scientists have found that geckos have gained and lost their adhesive toe pads several times, and some lineages of scorpions have gone from surface to cave dwelling and back, and lost their eyesight and regained it. The longer you don’t use something and it remains unexpressed, the harder it is to reactivate, but it isn’t impossible.

I would really love to see a study of the early development of these worms, especially to see if their larval forms have digestive tracts.

One other cool detail… Osedax have both male and female sexes, but the males live in a larva like state inside the female.

Worms = cool

A new gene in the influenza virus has been discovered. Let me pick up my teeth. Influenza just went from a genome of 10-11 genes to 11-12.

The gene is hidden in the code of another gene, and it appears to limit the severity of the immune response. If the mouse model is correct, when this gene works, the flu symptoms are less severe. If it is mutated, the flu is more severe and is more likely to kill otherwise healthy people.

The gene wasn’t discovered until now because it is found after the main gene on segment three starts. It basically is a second open reading frame (this is the link to the original paper in the journal Science), and is activated by a ribosomal frame shift. (Does this sound like it may be for an undergraduate genetics course? Oh yeah. But don’t be afraid of handing it to a gifted high school student.)

Basically, the gene is transcribed as normal, making the viral mRNA. The mRNA is then translated, and when the ribosome reaches the start of the internal gene, it slips, missing a nucleotide and the rest of the protein is produced according to the internal gene. This is similar to eukaryotic alternative splicing, and is a very cool way to get two genes coded into the space of one.

This produces a protein that represses the genes of the cell, and probably inhibits the cell from putting up the little red flags that tell the immune system that it has been infected. Less immune response, less chance for a cytokine storm, the nightmare scenario for flu.

Misc science goodness:
Neutron star racing across space 
Graphene may make for an efficient way to make salt water into fresh
Nice way to explain the different parts of the electromagnetic spectrum (xrays to visible light to radio waves) and their significance to astronomy
Why does coal become rare in the fossil record around 300 million years ago? Fungus that could break down lignin evolved about that time.
A rare freshwater mussel is facing extinction.
Animals from the Ediacaran period preserved by volcanic ash.

Teach on.

Science Tidbits for June 28, 2012

Looking for something to blow some time while doing something for science? Help map the moon! (via Token Skeptic)

On with the show.

In the June 20 list of science teaching tidbits, I talked about what senses you could ascribe to plants, and somewhat dismissed the concept that plants could “see.” Well, I didn’t put enough thought into it, and failed to consider the range of what “sight” means. Sight in flatworms can be something as simple as detecting the presence of light and moving towards it.

Daniel Chamovitz, of Tel Aviv University, in a Scientific American 60 second science blog post, points out that plants “see colors, they see directions, they see intensities.”

And beyond that, they respond to direction, through a process called phototropism, where the plant grows towards light.

The great thing about science is that you can be excited by being wrong.

Also from Scientific American is one of the most ignored members of our phylum, chordata, the sea squirt. We rarely do more than mention tunicates and lancelets in passing and move on to the better known and more popular vertebrates, which is really a shame. These oddities of chordata are very useful in spicing up a lecture on diversity. What is more different from a mammal than an organism that only swims as a larva, then settles down, becomes sessile, grows a shell and lives as a filter feeder for the rest of its life, resembling a mussel more than anything else?

The particular sea squirt of interest is a food item, nay, a delicacy in Chile and Peru, and has some incredibly odd reproductive habits, from a human point of view.

Finally, an incredibly old impact crater was recently found in Greenland, as in around 3 billion years old. It isn’t the biggest, but its the oldest. There are impact craters all over the world, some in our own back yards, many of which are not much to look at from the ground, but can stick out on a satellite image. For example, put 38.305000,-86.500000 in as your coordinates on google maps. As you zoom out, you will begin to see a broken ring. This is thought to be the site of a meteor strike in the ancient past of Indiana (I don’t have my roadside geology guide handy, or I’d give more details), and the surrounding land bears the shocked quartz, deformed bedrock and sedentary fill, and even the gravity density of a meteor site. Completely invisible from the ground.

The Kentland, Indiana crater is better known, but all kinds of things are just under our metaphorical noses. You don’t have to go to Arizona to stand where the sky fell. This makes the rare meteor crater site on the other side of the country or world a bit more close to home, and therefore, interesting.

If you want to go a little further in a physics class, here is a nice little experiment that you can do with fairly little setup or expense.

Teach on.

The life of the incoming freshman

Its their first time away from home for more than a week. They have run through all their clothes, and it is time to brave… the coin operated laundromat. How do you keep from stepping on toes? Is there a code of conduct? Why yes there is. Some of it is obvious, don’t be rude stuff. Other parts require that you think ahead, have enough quarters and sort your load before you get there.

Should you wait to for your freshmen to come to you to ask you, their adviser or professor, for help?

Well, you could do that, or you could take the initiative and send useful information to them by way of email, or set up a website with useful links like local bus schedules, or even more importantly, an explanation of what terms like “best if used by” on food mean.Even if students have a meal plan, they may have a mini-fridge with some milk, lunch-meat, cheese, etc, or they may have stopped by the student center/union, grabbed some food and squirreled it away for later. Helping students stretch their food budget while keeping them from making themselves sick? Not only is that good for you, but building the self esteem of new students and improving their first year experience is priceless.

Students with less outside stress perform better, learn more, are happier, and all of these contribute to a major goal of any institution of higher education… retention.

Teach on.

Toxic Tuesday – Arsenic and old peppermints


Not in Bradford, England, back in October of 1858.





Science Tidbits for June 26, 2012

Two quick news items for today and one video.










Teach on.

Caturday’s common ancestor #1





Science Tidbits for June 25, 2012


Now on with the Science!














-Charles Darwin





Teach on.