TWiEVO: This Week in Evolution

TWiEVOTo a molecular biologist, the word ‘evolution’ evokes images of fossils, dusty rocks, and phylogenetic trees covering eons. The fields of molecular biology and evolutionary biology diverged during the twentieth century, but new experimental technologies have lead to a fusion of the two disciplines. The result is that evolutionary biologists have the unprecedented ability to evaluate how genetic change produces novel phenotypes that allow adaptation. It’s a great time to start a new podcast on evolution!

Molecular biology is an experimental approach that was born in 1953 with the discovery of the structure of DNA. Its goal is to understand how cells and organisms work at the level of biological molecules such as DNA, RNA, and proteins. Some of the experimental tools of molecular biology include recombinant DNA, nucleotide sequencing, mutagenesis, and DNA-mediated transformation. The experiments of molecular biology often involve simplified, or reductionist systems in which much of the complexity of nature is ignored. Variation in individuals, populations, and the environment are set aside. Data produced by the techniques of molecular biology can lead to decisive conclusions about cause and effect.

Evolutionary biology embraces variation, and in fact attempts to explain it. The basis for variation in organisms is usually inferred by associating phenotypes, sequences, and alleles. The problem with this approach is that alternative explanations are often plausible, and conclusions are rarely as decisive as those achieved with molecular biology. We can turn to Darwin’s finches as a good illustration of the difference between fields. Darwin hypothesized that variation in the beaks of finches was a consequence of diet, but how such variation occurred was unknown. It was not until 2004 that it was shown that beak shape and size could be controlled by two different genes.

The techniques of DNA sequencing, mutagenesis, and the ability to introduce altered DNA into cells and organisms have been the catalyst for the fusion of molecular biology and evolutionary biology into a new and far more powerful science, which Dean and Thornton call a ‘functional synthesis’. As a consequence, genotype can be definitively connected with phenotype, allowing resolution of fundamental questions in evolution that have been puzzles for many years.

Microbes are perfect subjects for study by evolutionary biologists, as they are readily manipulable and rapidly reproduce. However no organism is now very far from the eye of this new science. Subjects as diverse as insecticide resistance, coat color in mice, evolution of color vision, and much more are all amenable to scrutiny by the ‘functional synthesis’.

This Week in Evolution will cover all aspects of the functional synthesis, irrespective of organism. My co-host is Nels Elde, an evolutionary biologist at the University of Utah. Nels has appeared on This Week in Virology to discuss the evolution of virus-host conflict, and his lab’s story on the evolutionary battle for iron between mammalian transferrin and bacterial transferrin-binding protein was covered on This Week in Microbiology.

You can find This Week in Evolution at iTunes and at MicrobeTV.

A virology course for all

Virology class 2013The spring semester has begun at Columbia University, which means that it is time to teach my virology course.

The fourth annual installment of my virology course, Biology W3310, has begun. This course, which I taught for the first time in 2009, is intended for advanced undergraduates and convenes at the Morningside Campus. Until I started this course, no instruction in virology had been offered at the Morningside Heights campus of Columbia University since the late 1980s. This is a serious omission for a first-class University. Sending graduates into the world without even a fundamental understanding of viruses and viral disease is inexcusable.

Course enrollment has steadily increased: 45 students in the 2009, 66 students in 2010, 87 students in 2012 and an amazing 195 students this year. I am gratified that so many students want to learn about the world of viruses. This year our class was moved into a wonderful lecture hall in the brand-new Northwest Corner building.

Readers of virology blog can watch every lecture in the course. You will find a videocast of each lecture at the course website, at my YouTube channel, and at iTunes University. The complete 2012 version of this course is available online, at iTunes University, and YouTube.

This year we will also be offering my virology course at Coursera. Details will be forthcoming.

To those who would like to know if the 2013 version of my course differs from the 2012 version, I reply: do viruses change? Some parts will be the same, others will be different. The goal of my virology course is to provide an understanding of how viruses are built, how they replicate and evolve, how they cause disease, and how to prevent infection. After taking the course, some of the students might want to become virologists. The course will also provide the knowledge required to make informed decisions about health issues such as immunization against viral infections. It should also be possible to spot badly constructed headlines about virology stories.

I am excited about teaching virology to 195 Columbia University students this year. But the internet makes it possible to spread the word even further. So far nearly 75,000 students registered for the iTunes University version of my 2012 virology course! As a professor used to teaching relatively small numbers of students in a classroom, this reach is truly amazing.