Science or Fiction, July 2012

About once a month, I get together with several friends and colleagues for the Lexington Skeptics meetup for dinner and conversation. The topics tend to run from recent science discoveries, pseudoscience controversies, scams and flim flam. Discussion sometimes ranges into religion and politics, but is always polite.

Many people find their way to “scientific skepticism” by way of podcasts like The Skeptic’s Guide to the Universe (SGU) and one of my favorite parts of the SGU podcast (which you should be listening to) is the Science or Fiction segment.

Briefly, the host, Steve Novella asks the co-hosts and guests to pick one fake story from a set of three or four. The others are true, at least in a technical sense. If a true story is turned into a false one and the detail changed is a number, the number is changed to an unreasonably high or low number.

Tonight’s Science or Fiction was a fun one, and led to a discussion of why certain things were possible or not. Read over the following three items, try to pick out the fictional news piece and then click through (or just don’t scroll past the science cat).

  1. Milk thistle slowed the progression of Hepatitis C infection in a placebo controlled clinical trial.
  2. Bacteria are being used to grow spider silk with the tensile strength of black widow spider silk.
  3. Injuries from laser hair removal have led to calls for regulation in Britain.

Continue reading

Science tidbits for July 2, 2012

Lots of tidbits, lots of links, enough to make a few tidbytes, even (8 tidbits = 1 tidbyte).

Feathers may have been an early adaptation, perhaps even basal, of Saurischian dinosaurs (which includes therapod dinosaurs), appearing so early in the evolutionary tree that many therapod dinosaurs (if not most) may have had feathers. Saurischian dinosaurs are one of the two major orders of dinosaurs, the other being Ornithischia, both named for the structure of their pelvic bones. Saurischian dinos have a lizard like hipbone, while Ornithischia has a bird like hipbone. Interestingly, it is the Saurischian group that is thought to have given rise to birds.

What kind of feathers, though? There are eight feather types that are documented within modern and extinct birds, all the way back to feathered dinosaurs.

Xu, X. and Guo, Y. (2009). The origin and early evolution of feathers: insights from recent paleontological and neontological data. Vertebrata PalAsiatica 47 (4): 311-329. – Hosted at wikipedia

Quoting wikipedia’s article on Feathers > Evolutionary stages

Feather evolution was broken down into the following stages by Xu and Guo in 2009:

  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
  6. Pennaceous feather with vane of barbs and barbules and central rachis
  7. Pennaceous feather with an asymmetrical rachis
  8. Undifferentiated vane with central rachis

However, Foth (2011) showed that some of these purported stages (stages 2 and 5 in particular) are likely simply artifacts of preservation caused by the way fossil feathers are crushed and the feather remains or imprints are preserved. Foth re-interpreted stage 2 feathers as crushed or misidentified feathers of at least stage 3, and stage 5 feathers as crushed stage 6 feathers.

Modern birds have feather types 4, 6, 7 and 8 (chicks have filament feathers similar to type 1). The dinosaur that is the subject of the research paper that sciencenews is presenting a press release on a 150 million year old fossil of Sciurumimus albersdoerferi, which has type 1 feathers. A dino covered with type 1 feathers would have looked kind of fuzzy, like a kiwi. Not the fruit, the bird. This supports other evidence for feathered dinosaurs in the therapod group existing as far back as 160 million years ago. Therapods are the dinosaurs come to mind when you think of Tyranosaurs or Velociraptors.

What I am most interested in is that feathers are made of a protein called keratin. Keratin is the waterproof filamentous protein that makes up the outer layer of your skin, hair and nails. Keratin is also present, in one form or another, in all vertebrates. Hooves, horns (like those of a rhino) and baleen are all also made of keratin. Amphibians produce keratin, but only on their feet and perhaps belly, as protection against abrasion, while lizards, snakes and all other reptiles produce keratin all over their skin, and it is one of the major evolutionary adaptations that let reptiles live away from water. Carl Zimmer, one of my personal science journalism heroes, has an article at NatGeo on the evolution of feathers, as well as the evolution of our understanding of the evolution of feathers. I highly recommend reading it and passing it along to interested students of all levels.

Depending on how and where they are expressed, they can make up very different structures, which is one of the primary concepts within evolution. Inventing the wheel is quite easy when the parts you need are already present and only need a modification here and an alteration there. With minor mutations here and expression changes there, scales become modified into feathers, which become altered into more complex feathers with further mutations, each becoming useful for different purposes. And all of this from one group of proteins with incredible versatility.

CERN is getting ready to tell couldn’t take the excitement and told us something about the Higgs boson. Great fun for physicists. I have no clue what it means. Dammit, I’m a doctor (biologist), not a doctor (particle physicist)! Luckily, there are people that can explain it.

BoingBoing has a great article up as a piece on cell division and embryogenesis in sea urchins. The videos there would make for great media pieces in the multimodal classroom.

You can learn a lot from fossils, even fossil poop. Yeah, sometimes, feces fossilize (and are called coprolites), and we can learn about the diet of the animal that produced it. In this case, the New Zealand Moa’s coprolites have been examined, and these exceptionally large flightless birds ate plants, and don’t seem to have been too picky. This can relate to the classroom quite easily in any lab where students examine owl pellets. This is a very similar experiment in some ways, examining the contents, but without the carbon dating and DNA analysis.

What drove the moa to extinction around 1500 CE? Humans arrived on the island before this point, and apparently moa were delicious. If only they had survived, I could have a 12 piece New Zealand Fried Moa bucket.

Eugenie Scott of the NCSE talking at the Global Atheist Convention 2012, via Token Skeptic. This talk has some great pearls of knowledge for regarding creationist attempts to do science, and how they don’t mesh with the evidence. (evidence they conveniently ignore)

I love parasites. They are seriously cool. For every animal that feeds itself, there is an animal that lives off of it as a parasite. Some of those parasites have parasites of their own.

The smallest of ants were thought to be safe from phorid flies, a parasite that lays eggs in the heads of ants. The larva emerges, eats the goodies in the ant’s head, and when it is ready to emerge as an adult fly, the head falls off and the fly comes out.

Well, size doesn’t matter to a newly described species of fly that is smaller (0.4 mm long) than any previously described member of the family. So far, the researchers have no idea what the host of this tiny parasite is, but you can be sure they are looking.

In any discussion of how organisms gain their food, parasitism comes up, and visceral examples like this fly can be very interesting to students.

Edited to add this video

Miscelania linkelist

Coffee. Need I say more? OK, history and pharmacology of coffee.
Via Jerry Coyne, wild macro photography of some very cool caterpillars, some of which should be hands off. BTW, the description on the page goes with the insect on the next page.
I would never work with chimpanzees. Even before you get to the ethical issues, they scare the E. coli out of me.
Ants that farm and raise aphids for honeydew and for food have altered the evolution of their livestock.
Mass extinctions can have subtle effects on evolution.
Want to have some fun in an ecology class? Give your students a paper on modeling bigfoot reports!
Interested in a challenging discussion on how to change behavior in a third world setting? Give the class this.
Via BoingBoing, reasons to hate standardized tests. My number one pick from this WaPo piece, ” because they measure only “low level” thinking processes.” Bloom’s Taxonomy? Anybody? Hello?

Science Tidbits for June 21 and 22, 2012

Good Morning, Tokyo. I promised tidbits by morning, and it is still morning on the other side of the planet.

Whenever I teach about the cell cycle, I discuss cancer, and when I discuss cancer and the cell cycle, I talk about how some anticancer drugs work in relation to the cell cycle. While my own dissertation work focuses on using cell cycle dependent drugs and making them more effective by tricking the cell into dividing with a second drug, all before it has repaired damage caused by first, I’m always looking for recent work that hits on this topic. This press release talks about using just such a “one two punch” to attack cancer cells. The full paper can be found here, but access is subscription limited. I suppose I’ll be hitting up the University library.

I love talking about flu as an example of… well, lots of things. Mutation rates, genes, viruses, zoonotic pathogens, genetic recombination, etc. One of the things I talk about is how close we are to an H5N1 pandemic. Right now, the H5N1 strains that are being monitored don’t pass from human to human very efficiently, which is one thing that keeps it from running rampant through the population. All it takes is a few small mutations and the virus can pick up the ability to pass from human to human, and it is only a matter of time before just such a mutant strain evolves. Hopefully, by that point in time, we will have universal influenza vaccines ready, or at least have methods approved for rapid vaccine production via cell culture. The chicken egg method is just too slow.

Do you know that the color you call blue is seen in precisely the same way as another person? A wavelength of 460 nm is a specific shade of blue. Do you see the same exact shade as another person? Does your brain interpret in precisely the same way?

We have no good way of knowing if my color blue is the same as yours, since every person has different eyes and different brains. Your brain, when you look around you, is receiving information from the surrounding world from your eyes, transferred along the occular nerves, and is decoding it. As it does this, it produces a simulation from that information. You can’t see some things that are there. You can’t see pigments that reflect in the ultraviolet range, but they are present, and many insects can see them. Illusions and mirages are excellent examples of errors in your interpretation of the world and how it is in reality.

This is especially true if you have certain genes for colorblindness. The “normal” person has three different types of cone cells in their eyes. They have trichromatic vision. These cones detect different ranges of color, and for each type of colorblindness, you lose one of those ranges. Your simulation is reduced pretty significantly for each malfunctioning cone cell type.

It turns out that there aren’t only people that have one fewer cone cell type, but some people have one extra type of cone cell, and are called tetrochromatic.

This is one of those little details that you can toss in to a lecture about vision or sex linked genes (some types of colorblindness are sex linked, and tetrochromatic vision definitely appears to be). I find that these kind of teaching tidbits can be a useful way of keeping students that are at the top of the curve right there, involved. They may already know a decent portion of the material, but if you toss in a few bits of trivia that they haven’t seen before, they pay attention for the new things that they didn’t already know about.

More fun Pollinator Week stuff from Bug Girl. Ignore the Burt’s Bees commercial part of the video, and enjoy the information about how bees are the true masters of interpretive dance, and how they are involved in pollination. Oh, did I mention that it is one of Isabella Rossellini’s wonderful videos about nature? Because it is.

Are you teaching a class about reproduction? Are you teaching a minimally mature class? Then fill them in on the oddities of animal penises (via Discovery News). The duck one is actually kind of useful if you are talking about prezygotic barriers to reproduction as a means of speciation. Ducks have penises and vaginas that can be species specific, which can prevent one species from being able to mate with another.

Ever have a student ask why you get brain freeze when you eat or drink something cold? Here is a nice video explanation.
Oh, and if you haven’t heard that Europe is working on increasing the involvement of girls in STEM (Science Technology Engineering Math) education, then you have missed out on one of the worst PR bungles ever. Why is it bad (other than being painful to watch)?

Sexist imagery decreases the performance of female students on tests in STEM subjects. Nicole (NoisyAstronomer) points out the problems in the campaign and also gives some good examples of what women doing science look like. (If you are on Google+, follow her for great astronomy news and information) Kylie Sturgess at Token Skeptic also has some great examples of women in science and a good takedown of the ad as well (Kylie’s podcast is pretty great, too).

Their examples are what get people interested in science. Normal people doing interesting things. And the great thing about this is that when you show minority groups involved in science, it increases their involvement, and doesn’t discourage people in majority groups. Their functional privilege makes such differences invisible to them. Well, except for the ones that need their privilege reinforced, and require that all discussions be about them.

Have a nice weekend. I’ll be calling people to push poll on evolution.

When does life begin? A scientific perspective

When does life begin?

I was driving back from a Louisville Area Skeptic‘s meetup and saw a billboard saying that a fetus has a heartbeat at 21 days.

Was that correct? More importantly, did it mean anything useful?

It’s not quite correct. Heart cells develop about 20 days after conception, and the fetal “heartbeat” is first detectable at about 22 – 23 days after conception, so 21 days is a bit early. Since pregnancy weeks (gestational age) are counted from the beginning of your last period (or 14 days before conception), we need to add two weeks to the above time-line if we are to use that framework. Let’s stick with time from conception.

Is it an actual heart?

No. It is a small amalgamation of cardiac muscle tissue. Cardiac cells beat rhythmically on their own, and in concert if they are in contact with each other. In the first week after heart cells develop (around 4 weeks post conception), they are a bulge, a tube-like formation. Between six and seven weeks after conception, the heart can pump a blood-like fluid through tubes like blood vessels.

Is that really useful in determining when life begins? Thats the wrong question altogether. The right question is “What is life?”

Life requires certain features. First of which is the capacity to reproduce, and not necessarily sexually. Your body has to replace old or damaged cells, heal wounds, grow. Second, life has to be able to carry information that can be passed on to the next generation of cells. This hereditary information is carried by cells in their DNA. Third, life has to be able to use energy to drive a metabolism. This means making proteins, burning sugars and fats or storing the same, reproducing, etc and to keep those reactions going. Finally, life must be able to respond and interact with its environment in some manner. Bacteria swim towards food, light or away from things that would kill the bacteria. Fungi grow towards food. Plants grow towards a source of light. Even quasi-alive viruses can interact with their environment as they come into contact with the appropriate molecules for their receptors to interact with. Flowing from these four functions of life is the process of evolution by natural selection.

Any one of our cells is alive, but without the whole body, they cannot meaningfully reproduce. Not into a whole new organism, not into a whole new human. You need to combine an egg cell and a sperm cell to form a fertilized egg in order to begin the process of cell division that produces a new human.

Does this mean that life begins at conception? Again, not quite. Sperm cells are alive. Egg cells are alive. Sperm cells and egg cells have all the features of life. Sperm and egg cells combined to form a fertilized egg that can divide.

Egg cells and sperm cells are alive.

Life doesn’t begin at conception, not at least, life as defined by science. Life continues.

When people ask when life begins, they are asking a metaphysical question. When does the soul enter the body?

We can’t use an instrument to detect the presence of a soul, let alone determine the moment of ensoulment. The soul is not a concept that can meaningfully be examined by science, no matter how strongly you believe in it. Until someone develops a device or test that can reliably detect a soul, science can’t consider this as a valid question.

Don’t ask a scientist if you are asking for an answer that helps you win a political or religious argument. The answer you get won’t always be the one you want.

The Creation “Museum”

Why would I go to a creation museum?
creozerg robsterFCD 109
I don’t believe in a special creation, to put it bluntly. I have no question that evolution by natural selection is fact as well as solidly grounded theory.  I find the whole concept of a 27 million dollar facility pushing a narrow interpretation of a creation myth to be offensive, when one could have sent those millions to, say, upgrade the facilities of a teaching hospital in Africa, or fund clinics in the slums of central America, or promote polio vaccination programs worldwide… the list of real charitable projects would go on and on and on. And if you would prefer those dollars be used for US charities, try Habitat for Humanity or the Susan G. Komen breast cancer charity, or the Secular Students Alliance (more on this group in a post to come).

Why? Because my students come from varied backgrounds and with this “museum” only a 90 minute drive from home, some will have visited this place. While I am familiar with most of the claims of creationists of many stripes, thanks to TalkOrigins and The Counter Creationist Handbook (which I am holding above, and if you are a science educator, you should own this book and keep it in your office or classroom), it is always best to see these claims firsthand so that you can see their claims firsthand, how they are presented, etc so that you can be better prepared to respond.

Also, because there was a large group going, I didn’t have to pay $22 to get in, just ten. I’ll be offsetting that with donations and dues payments to a variety of pro science education groups or skeptical organizations, such as the NCSE, CSI and SSA, among others. Consider it Idiocy Offset Credits, sort of like offset credits of the carbon type.

Finally, PZ Myers, lord of the squid, was going, and I wanted to get a chance to see if fire really did shoot from his eyes and if bats darkened the skies with their leathery wings above him, blotting out the sun. Sadly, his reputation in this manner has been greatly exaggerated.

creozerg robsterFCD  096

My tie has the periodic table on it. I was ready to teach the controversy between four elements and all those hundred or so elements that scientists keep adding to every now and then. PZ’s tie, on the other hand is one of two crocoducks, the other belonging to Richard Dawkins.

What did I find? Continue reading