Basic Biology
clock | July 12, 2008Abbie and PZ chat about the recent discoveries in biology, how exciting those discoveries are, and how annoying it is when Creationists try to put a damper on such excitement:
clock | June 16, 2008A dozen or so years ago, I drove my Biochemistry prof to tears with questions - she had 200 people in front of her and she tried hard to make Biochem interesting enough not to get us all bored to tears, and she was pretty good at that, as much as it is possible not to make people bored to tears with Biochem. But my questions exasperated her mainly because she could not answer them, because, as I learned later, the field of biochemistry was not able to answer those questions yet at the time: questions about dynamics - how fast is a reaction, how long it takes for a pathway to go from…
clock | June 15, 2008Miriam points to this set of pictures of the development of the chicken embryo. As I have written before, I did have to learn how to precisely stage the chick embryos, both the older stages and the early stages, in order to manipulate them at exactly the right time. Cool pics.
clock | May 12, 2008According to the referrers pages of my Sitemeter, a lot of you are excited by strange penises, strange penises, strange penises and strange penises (or something like it). So, today we have to move to a different topic, traffic-be-damned, for those without phallic fixations. So, read on (first posted on July 21, 2006)....
If science is all you care for you can skip to the bottom of the post because the main character of today's story will be introduced with a poem (also found here):
The Conjugation of the Paramecium
by Muriel Rukeyser
This has nothing
to do with
propagating
The species
is…
clock | May 11, 2008It takes 38 minutes for the E.coli genome to replicate. Yet, E.coli can bo coaxed to divide in a much shorter time: 20 minutes. How is this possible?
Larry poses the riddle and provides the solution.
The key is that complex biochemical processes are taught sequentially, one by one, because that is how we think and process information. Yet, unless there is a need for precise timing (in which case there will be a timer triggering the starts and ends of cellular events), most processes occur all the time, simultaneously, in parallel. How do we teach that?
clock | May 4, 2008
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 | March 16, 2008Learn everything you need to know about protein structure, explained clearly and as simply as the topic allows:
Beta Strands and Beta SheetsLoops and TurnsLevels of Protein StructureExamples of Protein StructureEvolution and Variation in Folded Proteins
I think these should be included into the Basic Concepts collection.
Update: Larry has put together a compilation of all his bog posts on Protein Structure.
clock | March 3, 2008Get yourself free PDFs of old biology/taxonomy books and papers courtesy of Biodiversity Heritage Library:
Ten major natural history museum libraries, botanical libraries, and research institutions have joined to form the Biodiversity Heritage Library Project. The group is developing a strategy and operational plan to digitize the published literature of biodiversity held in their respective collections. This literature will be available through a global "biodiversity commons."
Participating institutions:
* American Museum of Natural History (New York, NY)
* The Field Museum (Chicago…
clock | March 3, 2008News from SCONC:
Oliver Smithies is the Nobel-Prize winner next door. A professor at UNC for almost 20 years, Smithies got the nod from Stockholm last fall. He will give a seminar at the Friday Center on Thursday March 6 at 6:30 p.m. in a lecture hosted by the Carolinas Chapter of the American Medical Writers Association.
Along with Mario Capecchi and Martin Evans, Smithies was recognized for his research on embryonic stem cells and DNA recombination in mammals. Their work on gene targeting in mice made it possible to study individual genes in health and disease--a fundamental breakthrough…
clock | February 19, 2008I tried to understand what DNA barcoding is, as everyone is talking about it. And I tried reading a couple of papers about it - I am a biologist, so I should have understood them, but nope, I was still in the dark.
So, what does one do? Waits for a science blogger to explain it. And so it happens, Karen explained it yesterday. I read it. Slowly and carefully. Only once. And I grokked it all!
clock | February 3, 2008Oh, how I wish eSkeletons website existed back at the time I was teaching anatomy! Very, very cool! You can focus on human bones only, look at movement, insertions and origins, etc. Or you can make comparison between bones of several primates. Thanks Anne-Marie.
clock | January 26, 2008Olivia Judson wrote a blog post on her NYTimes blog that has many people rattled. Why? Because she used the term "Hopeful Monster" and this term makes many biologists go berserk, foaming at the mouth. And they will not, with their eye-sight fogged by rage, notice her disclaimer:
Note, however, that few modern biologists use the term. Instead, most people speak of large morphological changes due to mutations acting on single genes that influence embryonic development.
So, was Olivia Judson right or wrong in her article? Both. Essentially she is correct, but she picked some bad examples,…
clock | January 12, 2008OK, this may not be very new, but for all of you taking a look at science in North Carolina next week due to the focus on the Science Blogging Conference, The Scientist has published a number of essays looking at every aspect of Life Science in the state - check it out: The State of Life Sciences.
For the latest news on life science in North Carolina, visit the Bioscience Clearinghouse, a very useful website hosted by The North Carolina Association for Biomedical Research.
clock | December 22, 2007On Pilobolous:
When I first wrote my post on Pilobolus (here and here) I really wanted to do something extra, which I could not do at the time. If you scroll down that post, you will see I reprinted the Figure 1 from the Uebelmesser paper. What I wanted to do was find (and I asked around for something like that) the exact times of dawn and dusk at the site where Uebelmesser did her work and thus be able to figure out the dates when the tests were done and the exact phase-relationship between the dawn and the time when Pilobolus shoots its spores.
Now, I see that such a chart exists (via) and…
clock | December 16, 2007That is one of the phrases that has been getting on my nerves for years now. So, I chuckled when I saw Keith Robison explain why that is not such a good corporate slogan.
I'll add another one to his funny list:
- Most of our organization sits there inert and dead while all of the work is performed by janitors, cooks, chauffeurs and outside contractors.
clock | November 28, 2007
When Wilhelm Johannsen coined the word "gene" back in 1909 (hmmm, less than two years until the Centennial), the word was quite unambiguous - it meant "a unit of heredity". Its material basis, while widely speculated on, was immaterial for its usefulness as a concept. It could have been tiny little Martians inside the cells, it would have been OK, as they could have been plugged into the growing body of mathematics describing the changes and properties of genes in populations. In other words, gene referred to a concept that can be mathematically and experimentally studied without a…