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.

TWiV 300: So happy together

Recording together for the first time, the hosts of the science show This Week in Virology celebrate their 300th recording at the American Society for Microbiology headquarters in Washington, DC, where Vincent  speaks with Dickson, Alan, Rich, and Kathy about their careers in science.

You can find TWiV #300 at

Celebrating 300 episodes of This Week in Virology

TWiV 300This Week in Virology, the podcast about viruses – the kind that may or may not make you sick, celebrates its 300th episode on Tuesday, August 26, 2014 with a live recording at the Washington, DC headquarters of the American Society for Microbiology. This special episode will be part of the ‘Microbes after Hours’ series, and will feature the TWiV hosts Vincent Racaniello, Dickson Despommier, Alan Dove, Rich Condit, and Kathy Spindler recording together in person for the first time.

TWiV 300 will be live-streamed, but if you live in the Washington, DC area, you are welcome to join us and watch the episode in person. We have a limited number of seats available on a first come, first serve basis. Click the RSVP link below to register.

Date: Tuesday, August 26, 2014

Reception from 6-7 PM at ASM Headquarters, 1752 N Street, N.W. Washington, D.C. 20036-2904

TWiV 300th Episode live from 7-8 PM RSVP required to attend.

Ten years of virology blog

Vincent Racaniello

Photo by Chris Suspect

Ten years ago this month I wrote the first post at virology blog, entitled Are viruses living? Thanks to EE Giorgi for pointing out the ten year anniversary, and also for publishing an interview with me at her blog, Chimeras.

Here is how this blog got started: in June 2004 the second edition of our virology textbook, Principles of Virology, had just been published. While the textbook had so far done well, its audience was limited, and I wanted to find ways to better spread information about viruses. At the time I had a hosting account that I used to publish a website for our cub scout pack, and while visiting the administration page, I noticed an option to install blogging software. The idea then came to me to start blogging about viruses, so I looked for a good domain name. All of the virology names were taken except for, so I bought that, and set up the blog. An artist made the logo, using an image of poliovirus bound to its cellular receptor; this structure was the product of a collaboration between my lab and those of Jim Hogle and Alasdair Steven. Then I wrote my first post. Discussing whether or not viruses are living seemed like a good introductory topic, and I used some ideas that had been published in our textbook.

To my surprise, after a few months the post began to attract comments, and to this day it remains one of the most commented posts on virology blog. My views on whether or not viruses are living have certainly evolved; a more accurate summary of my thoughts on this subject would be The virus and the virion.

I like to think that blogging has been a pathway to all of my other efforts to communicate information about viruses. Blogging brought me into the world of social media, leading me to start accounts on Twitter, Facebook, and Google Plus. Four years after virology blog, I started my first podcast, This Week in Virology, which is approaching one million downloads each year (we now have four science shows, including This Week in Parasitism, This Week in Microbiology, and Urban Agriculture). I began teaching an undergraduate virology course at Columbia University in 2010, and I have used video recordings of my lectures to teach virology at iTunes University and Coursera. I have had wonderful opportunities to interview virologists at colleges and scientific meetings; some of these can be found at my YouTube channel. I believe that I have shown that scientists can effectively communicate their field to the general public, and I hope I have inspired some of my colleagues to emulate my efforts.

For the first 20 years of my career I taught virology to roughly 200 students every year, for a total reach of four thousand people. My blogging, podcasting, and online teaching now reach millions in over 170 countries. It all started with a blog.

I have been lucky to reach so many people, in different ways, with information about viruses. But I still love blogging, and I will be writing about viruses here as long as I my brain and body permit. My sincere thanks to everyone who has visited virology blog and has been part of this engaged and excited community.

ASM General Meeting 2013 Denver

Just finished recording episodes of TWiV and TWiM at the 2013 annual meeting of the American Society for Microbiology in Denver, Colorado. Here are some behind the scenes photos. Podcast episodes will be published later this week.

ASM Live!Maloy and RayperAndrea and Ray on the camsASM Live! teamSuspect deviceProducer Chris Suspect
Ray on cameraTWiV audienceTWiV 234 panelShenk, EldeTWiV fansKen Stedman
TWiM audienceTWiM panelDenver storm arriving

How to read a scientific paper

On episode #169 of This Week in Virology we had a good discussion about how to read a scientific paper. Many individuals have asked about making this into a separate audio file, so here it is.

Click the arrow above to play, or right-click this link to download our thoughts on how to read a scientific paper (22 MB .mp3, 30 minutes).

Transcript of this discussion (pdf).

Epidemiologist Michael Walsh has shared a PowerPoint presentation on this topic (482 KB PowerPoint file).

TWiV live in Dublin

Join us for a live-streaming episode of This Week in Virology from the Society for General Microbiology 2012 Spring Conference in Dublin, Ireland. My guests for this special episode are Connor Bamford, Wendy BarclayRichard Elliott, and Ron Fouchier.  Watch the live stream below which starts on Monday, 26 March at 3:30 PM GMT (10:30 AM EST | 7:30 AM PST). If you have questions during the broadcast you can tweet them using the #TWiV hash tag.

You can use to calculate when the live streams will start in your area.

If you are using an iOS device, you will not be able to see the live stream below as it is flash encoded.

(If you don’t see the video and it is after 3:15 GMT, please refresh the page.)

TWiV 166: Breaking and entering

npc1 ebolaHosts: Vincent Racaniello, Dickson DespommierRich Condit, and Alan Dove

Vincent, Dickson, Rich, and Alan review cell proteins essential for entry of hepatitis C, Ebola, and measles viruses.

Please help us by taking our listener survey.

Click the arrow above to play, or right-click to download TWiV 166 (59 MB .mp3,  98 minutes).

Subscribe to TWiV (free) in iTunes , at the Zune Marketplace, by the RSS feed, by email, or listen on your mobile device with the Microbeworld app.

Links for this episode:

Weekly Science Picks

Dickson – What are you swimming with?
Rich –
Twelve monkeys
AlanKindle Touch
Vincent – Microbe news (thanks to Dave Winer)

Listener Pick of the Week

EricThe Nature of Things with David Suzuki
LanceTrials and Errors (Wired)

Send your virology questions and comments (email or mp3 file) to, or call them in to 908-312-0760. You can also post articles that you would like us to discuss at and tag them with twiv.

Popularização da ciência através de podcast

luizaFor those who do not read Portuguese, the title of this post is “Popularization of science through podcast”. During my visit to Brazil last month, I was interviewed by a Ph.D. student, Luiza Montenegro Mendonça, from the Federal University of Rio de Janeiro. Luiza is taking a course on scientific divulgation, and students are required to produce a podcast each week which is published on the course website. Luiza’s brief (~5 min) conversation with me can be found on the ICB (Instituto de Ciências Biomédicas) website, and it’s available in both English and Portuguese. If you read Portuguese, you should also check out the home page of the ICB website.

Luiza is very interested in teaching the public about science, but does not feel that podcasting is right for her. Instead, she plans to write a science blog in Portuguese. When her blog launches we will be sure to note it here.

TWiV 154 transcript

Thanks to TWiV listener Janet for transcribing episode #154, ‘Symbiotic safecrackers’. A pdf file of the transcript can be found on the post for that episode. A list of the episode transcripts is also available.

TWiV transcripts are all listener-generated, for which we are extremely grateful. If you would like to transcribe an episode, please let me know at, to avoid duplication of effort. We will provide a TWiV coffee mug as a token of our gratitude.