Basic Biology
clock | November 24, 2007Or, Happy Evolution Day! It's time for a party!
It is easy to look up blog coverage - if you search for "Origin of Species" you mostly get good stuff, if you search for "Origin of the Species" you get creationist clap-trap as they cannot even copy and paste correctly (hence they are better known these days as cdesign proponentsists).
Pondering Pikaia and The Beagle Project Blog were first out of the gate this morning with wonderful posts.
Here is a recent book review of the Origin by someone who knows some biology and another one by someone who does not - both are quite nice and eye-opening.…
clock | October 8, 2007Dr. Oliver Smithies, the Excellence Professor of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, NC, USA, together with Mario R. Capecchi and Martin J. Evans, won this year's Nobel Prize in Physiology and Medicine:
This year's Nobel Laureates have made a series of ground-breaking discoveries concerning embryonic stem cells and DNA recombination in mammals. Their discoveries led to the creation of an immensely powerful technology referred to as gene targeting in mice. It is now being applied to virtually all areas of biomedicine - from basic research to the…
clock | September 27, 2007
When teaching human or animal physiology, it is very easy to come up with examples of ubiqutous negative feedback loops. On the other hand, there are very few physiological processes that can serve as examples of positive feedback. These include opening of the ion channels during the action potential, the blood clotting cascade, emptying of the urinary bladder, copulation, breastfeeding and childbirth. The last two (and perhaps the last three!) involve the hormone oxytocin. The childbirth, at least in humans, is a canonical example and the standard story goes roughly like this:
When the…
clock | August 11, 2007I have linked to and posted pictures of Eva Vertes from SciFoo before and you may ask: "Who is she? Why was she invited there?" The Wikipedia page I linked to earlier is a short stub and full of errors. So, to make it clear, see this page as well as comments on this talk she gave two years ago when she was 17:
clock | July 18, 2007I can't stay away (a charming spell?) from the series that Anne-Marie is churning out at a supernatural rate (what kind of magic?). Here are the latest three installments, totally enchanting:
Conservation BiologyThe Botany of WandsKin selection
clock | July 7, 2007You should check out all of my SiBlings' Friday Blogging practices, then come back here for a new edition of Friday Weird Sex Blogging. Last week you saw an example of a corkscrew penis. But that is not the only one of a kind. See more under the fold (first posted on July 14, 2006)...
Some birds also have spiral tools. For instance, see this 20-cm penis of an Argentine lake duck (Oxyura vittata) (from this paper: The 20-cm Spiny Penis of the Argentine Lake Duck (Oxyura vittata) (pdf)):
The same author, Dr Kevin McCracken of the University of Alaska, Fairbanks, later found an even longer…
clock | July 5, 2007You really think I am going to put this above the fold? No way - you have to click (First posted on July 7, 2006):
Today's lesson is on the reproductive anatomy of the domestic pig (Sus scrofa domestica), which probably applies to the wild species in the pig family as well. Although we may reflexively think about invertebrates when pondering diversity of copulatory organs, mammals are not too bad in that department either. After all, the sperm is delivered in some species into the vagina (e.g., dog), in others into the cervix (e.g., pig) and in yet others into the uterus (e.g., horse), so…
clock | June 17, 2007Here is an example of perfect science blogging. It starts seemingly innocuously, with a quiz: Monday's Molecule #30, where you are supposed to figure out what the compound is.
Then, after a couple of days, there is a post that you may not even realize at first is related to the first one: Bacteria Have Cell Walls
Another day or two, and A and B get connected: How Penicillin Works to Kill Bacteria
But how do we know this? Well, some people figured it out: Nobel Laureates: Sir Alexander Fleming, Ernst Boris Chain, Sir Howard Walter Florey - and now you know how we know.
Finally, putting…
clock | June 12, 2007Literally. If you want to know how to figure out what your slug has eaten today, just ask Aydin.
clock | June 2, 2007Evolution of direct development in echinoderms
It's been several years since I last heard Rudolf Raff talk about his work and apparently he's been busy in the meantime. The new stuff is exciting, and PZ knows how to explain it really well.
clock | May 30, 2007Is natural selection omnipotent or are there developmental constraints to what is possible and it is only from a limited range of possibilities that natural selection has to choose? The tension betwen two schools of thought (sometimes thought of in terms of pro-Gould and anti-Gould, as he has written much about developmental constraints and against vulgar adaptationism) is still alive and well. It is nice to see someone actually do an experimental test of the thesis:
Why Are There No Unicorns?:
Why are there no unicorns? Perhaps horses develop in a way that cannot be easily modified to…
clock | May 21, 2007No more blogging until late tonight or tomorrow morning as it is a Monday and on Monday evenings I teach. Today's topic is Biological Diversity, from its origins through its evolution to its current state. Fun!
clock | May 15, 2007Everybody is talking about Encyclopedia of Life these days. It is alll still very Beta - we'll wait and see how it turns out in the end. Many are enthusiastic, some are skeptical. But, what happened to the Tree of Life? Remember it from 1995 and after? I found it useful during the last decade for teaching and finding info. Why build a whole new thing when the old one could be updated and modernized instead - it is already chockful of information.
clock | April 26, 2007I am teaching my BIO101 again starting this Monday. The class is very small, so the discussions and student presentations will not last very long. Thus, I will have extra time at the end of each lecture. This can be a good time to show some videos. So, if you know of good movies available online or that can be ordered as CDs or VHS tapes, let me know in the comments (check the link for the topics I need to cover). I have a couple of ancient tapes whcih will do in a jiffy, but I am looking for more recent and better stuff. Keep in mind that this is VERY basic biology. Thus, the cool…
clock | April 12, 2007Sperm Cells Created From Human Bone Marrow:
Human bone marrow has been used to create early-stage sperm cells for the first time, a scientific step forward that will help researchers understand more about how sperm cells are created.
Gives a new meaning to the word "boner", doesn't it? OK, too late at night - I am losing all sense of what is appropriate on a science blog. Actually, the study is interesting besides its potential for humor.
clock | April 11, 2007How did I miss this!?
Knut Schmidt-Nielsen, one of my personal scientific idols, died on January 25th, 2007at the age of 92.
He has re-invented, or perhaps better to say invented, the field of comparative physiology (now often refered to as 'evolutionary physiology'). He wrote the standard textbook in the field - Animal Physiology: Adaptation and Environment, that he updated through several editions, from which generations of biologists (including myself) learned to think of physiological mechanisms as adaptations.
He wrote a definitive book on Scaling, as well as a wonderful autobiography…
clock | April 7, 2007The Bodies Exhibition is coming to The Streets at Southpoint in Durham.
My wife saw it last year in NYC. My daughter will probably be too squeamish for it, but I'll try to get my son to come with me.
Once I go....well, it is certainly a bloggable event.
clock | March 31, 2007A review of evo-devo (Jenner, R.A., Wills, M.A. (2007) The choice of model organisms in evo-devo. Nat Rev Genet. 8:311-314. Epub 2007 Mar 6.) is starting to make rounds on the blogs. I cannot access the paper (I'd like to have it if someone wants to e-mail me the PDF), but the press release (also found here) is very vague, so I had to wait for some blogger to at least post a summary.
This is what the press release says (there is more so click on the link):
The subject of evo-devo, which became established almost a decade ago, is particularly dependent on the six main model organisms that…