Darwin Turns 209 Next Week. And Here’s the Perfect Playlist to Help Us All Celebrate.

February 12th is Charles Darwin’s birthday; this year he turns 209.

There are many ways to celebrate. You could crack open your old copy of On the Origin of Species, his groundbreaking work describing the theory of evolution. You could book a trip to Down House, where he lived and raised his family. Or, if you’re looking for something impactful, make a contribution to defend evolution education (for a good birthday present you can even do it in his name).

An additional way to celebrate is with music. Darwin-themed songs have been highlighted before, and this is a wonderful option to explore. However, in this post I am proposing a playlist of another sort, in which it is the songs’ arrangement, rather than their content, that honors Darwin.

Today, evolutionary relationships are often represented using a diagram called a phylogenetic tree. (In fact, Darwin sketched one as early as 1837.) In a phylogenetic tree, organisms are placed at the tips of lines called branches. At certain positions in the diagram, adjacent branches intersect. These points of intersection are called nodes. A node represents a common ancestor—a point in the past when a single ancestral population split to give rise to two separate lineages. Clusters of intersecting branches, incorporating all of the species that are descended from a given ancestor, are called clades.

My playlist is organized in exactly the same way. It has 16 songs, each named for a different biological organism. Each song is positioned at the end of a branch; these branches, in turn, are arranged to reflect genealogical relationships.

I selected my songs based on two considerations. First, I wanted a diverse range of organisms, belonging to several different phyla. At the same time, I also wanted to restrict my playlist to famous songs—titles that most people would recognize immediately.

At the top of my list, “Who Let the Dogs Out” is paired with “Hungry Like the Wolf,” reflecting a close evolutionary relationship between dogs and wolves.

Positions 3 and 4 of the playlist are occupied by two more distantly-related carnivores: “The Fox” (better known as “What does the Fox Say?”) and “Eye of the Tiger.”

At positions 5-7 is a second clade of mammals, which diverged from the carnivores approximately 100 million years ago. This clade consists of a lagomorph-themed song: “White Rabbit,” together with a pair of songs named for primates: “Piano Man” and “Shock the Monkey.”

Bird-themed songs form a clade at positions 8-10: “Blackbird,” “When Doves Cry,” and “Peacock.”

Invertebrates occupy positions 11-13. Two arthropods, “Rock Lobster” and “Fireflies,” are paired; a mollusk-themed song, “Octopus’ Garden,” is present on an adjacent branch.

The remaining branches, rounding out the playlist, are devoted to plants and plant products: The Presidents of the United States of America’s “Peaches,” Eric Clapton’s “Cocaine” (cocaine is derived from any of several plants in the genus Erythroxylum), and Maroon 5’s “Sugar.”

The only thing more fun than this playlist is the process of creating one of your own. And you can do that, just like I did, in five easy steps.


The full playlist!

1) Select your songs

Your selection criteria—and musical tastes—will likely differ from mine. You might also wish to challenge yourself by honing in on one specific section of the tree of life. Consider, for example, a playlist that is devoted just to flowering plants, or just to protostomes, or just to vertebrates.

Whatever your criteria, though, a variety of search engines can assist you. At Songfacts.com, for example, you can search for “songs with flowers in the title”.  Or for “songs with animals.”

2) Convert your song titles to species names. (Sites like Wikipedia can help.) In this conversion, for example, “Peaches” becomes Prunus persica.

3) Save a list of the species in .txt format

4) Visit TimeTree.org

Scroll to the bottom of the page. At “Load a List of Species,” upload your .txt list. Then, Bam!, Time Tree will generate a phylogenetic tree.

5) Recreate the tree replacing the species names with the song titles

And then, Voilà!: You have a playlist.

As you play around with your playlist, you should also remember: equivalent trees can be written in many different ways. So feel free to headline your playlist with whatever song you’d like: “The Yellow Rose of Texas,” “Hound Dog,” “I Am the Walrus,” whatever. Then tweak the arrangements of the other songs accordingly. And you’ll still have a perfectly accurate tree.

Whatever your plans for February 12th, I hope that you’ll consider making a phylogenetic playlist a part of the celebration. Use mine—you are very welcome to it. Or else build one of your own.

As you listen to your playlist, reflect upon the deep familial connections that link all forms of life. Think, too, about Darwin: the author of the revolutionary conceptual framework that underlies your playlist—the same framework that today enables us to make sense of biology.

And wish him, with all your heart, a happy 209th.

Bio: Rachel Rodman has a Ph.D. in Arabidopsis genetics, and presently aspires to recontextualize all of art, literature, and popular culture in the form of a phylogenetic tree. Won’t you help her?

Creationism invades Europe

Like a novel pathogen, or a deadly infectious disease, creationism is spreading. After decades of being limited to a subset of american culture, it has gone global.

There is a long history here, of many different factions in different countries and how they are attacking evolution, both in education and policy.

Read about it over at Scientific American.



Happy Darwin Day!

Panagaeus cruxmajor. Image via Wikimedia Commons.

This being the 12th of February, the birthday of Charles Darwin, here’s an excerpt from his autobiography (pages 62-63), about the inordinate fondness for beetles he had, as a student at Cambridge:

But no pursuit at Cambridge was followed with nearly so much eagerness or gave me so much pleasure as collecting beetles. It was the mere passion for collecting, for I did not dissect them and rarely compared their external characters with published descriptions, but got them named anyhow. I will give a proof of my zeal: one day, on tearing off some old bark, I saw two rare beetles and seized one in each hand; then I saw a third and new kind, which I could not bear to lose, so that I popped the one which I held in my right hand into my mouth. Alas it ejected some intensely acrid fluid, which burnt my tongue so that I was forced to spit the beetle out, which was lost, as well as the third one.

I was very successful in collecting and invented two new methods; I employed a labourer to scrape during the winter, moss off old trees and place [it] in a large bag, and likewise to collect the rubbish at the bottom of the barges in which reeds are brought from the fens, and thus I got some very rare species. No poet ever felt more delight at seeing his first poem published than I did at seeing in Stephen’s Illustrations of British Insects the magic words, “captured by C. Darwin, Esq.”

The Darwin Correspondence Project, which is digitizing Darwin’s entire collection of letters—basically turning the Victorian version of e-mail into the more current format—notes that the specific species of beetle that young Darwin “could not bear to lose” was probably the Crucifix Ground Beetle, Panagaeus cruxmajor. A good 30 per cent. of the Wikipedia page for P. cruxmajor consists of this very anecdote.

Happy Darwin Day!

Charles Darwin

Cross-posted from Denim and Tweed.

Charles Darwin, who first proposed that natural selection could be responsible for “descent with modification,” the observation (which predates Darwin) that living species change over time and give rise to new species, was born on this day in 1809.

By all accounts, Darwin was a geek’s geek—uncomfortable in high-pressure social situations and devoted to the fiddly details of his scientific work. But he also seems to have been a quietly friendly chap, keeping up a tremendous volume of correspondence with other scientists all over the world, and, most charmingly, bringing his children into the fun of puzzle-solving that lies at the heart of science.

I don’t know of better proof of this than this account of Darwin’s familial experimentation, produced for NPR by Robert Krulwich with writer David Quamman, a couple years back around the Darwin Bicentary. (Thanks to Madhusudan Katti for reminding me about it!)


Christmas is upon us, what field guide, obscure tome and biography of Darwin would you bring to a far away island?

I’ve been looking through my bookshelf and would like your help with a bit of a thought experiment. In evolution and ecology we are often concerned about when we can see past the complexities of the natural world and get to general, reliable knowledge. In a sense this is a matter of taking lots and lots of information and boiling it down to a small set of facts that we think “really” matter. Due to a recent job change I’ve had to get rid of a large section of my book collection and I would like chat with you guys about which pieces of biology were “general” enough to take on a long voyage.

Sure the question “what book would you take to a far away island” is supposed to be clichéd, but this June the question became quite literal for me. I was working at a post doc at the National Institute for Mathematical and Biological Synthesis at the University of Tennessee in Knoxville (USA) and was offered a job as a lecturer at the at the University of Canterbury in Christchurch New Zealand. The job had a lot of what I was looking for, a chance to do research, some teaching and an amazing local to think about biology. The one thing that this job did not include was a hefty budget to move my huge collection of books to a distant hemisphere.

Me tramping in New Zealand.

People who know me well will realize how painful this would have been. I am a compulsive buyer of field guides and if I spend more than a day or two in some new place I immediately track down the nearest visitor center and pick up a copy of any field guide I can find. When Jeremy Yoder found out I was moving to Tennessee he gave me (not entirely in jest) a guide to an obscure group of algae in Great Smoky Mountains National park as a going away present. That book (and many more) are now residing in my parent’s basement separated from the few biology books that I thought would help me when I moved to a new hemisphere. Let me tell you about how useful I have found nature guides, hefty biology books and Darwin biographies.

First, two examples of field guides:

WEEDS- Sadly enough it is pretty easy to transfer knowledge of weedy plants to my new home in New Zealand. I didn’t take a field guide to the weeds of North America with me, but inside the city of Christchurch this would have been quite in handy.  I now have a student working on mallows http://en.wikipedia.org/wiki/Malva, a plant I recognized immediately from North America. Mustard plants, docks http://en.wikipedia.org/wiki/Rumex and invasive garden species like the mint in my garden are all thriving here as they would in many parts of North America. I would argue that this is not because ecologists have a great general understanding of weedy biology, rather it is because humans have now moved a massive number of weedy plants throughout cruddy sites in cities throughout the world.

TREES- The native trees here blow my mind. I’ve bought a few beautiful guides to the trees of New Zealand, but they are so different from everything I’ve ever seen before that no field guide from North America will be any help. The best I can say is that there are rhyming patterns in the trees here. In dry sites you will find Cabbage Trees, which looks surprisingly like the Joshua trees I’ve studied in North America. When you climb up in the mountains here you get into beautiful southern beech forests that remind me just a bit of the Douglass fir forest in the Pacific Northwest.

Cabbage tree, Canterbury New Zealand

Joshua Tree, California

Now for the heft:

To be a scientist means reading a huge number of books on seemingly arcane topics. Let me give you some preliminary notes on whether these books have helped me to make sense of biology in my new home.

COEVOLUTION- I’ve spent a lot of my research time trying to understanding when reciprocal adaptation between species (coevolution) matters in nature. As a result I’ve brought a copy of John Thompson’s The Geographic Mosaic of Coevolution with me. The first thing that strikes me about this subject is that many of the examples John uses are not from this part of the world. New Zealand has no Yucca moths, no super toxic newts, and no colorful Heliconia butterflies. The natural history of New Zealand is amazing but fewer people have studied coevolution here (note however that contributor Devin Drown has done super cool stuff on this topic in New Zealand). As a result I am really not sure how to apply thinking on coevolution to what I see around me. What this book might help me to do is to expect the unexpected. Reading this academic work you get the sense that under every log, and inside every bog there is some bizarre way that one species evolves to deal with another species. The book makes me feel like the world is a very noisy place and that can at least be an incentive to get messy and closely watch the happenings of the natural world.

SPECIATION- I’ve brought a copy of Coyne and Orr’s book Speciation that is a fairly recent synthesis of what we know about the origin of new species. I actually think some of the arguments in this guide are a handy starting point for thinking about diversity in an unfamiliar part of the world. To take one example, as I learn more about the species in New Zealand I keep in the back of my head one of the main theses of this book, that newly formed species tend to occur in somewhat different geographic regions. I don’t want to go into all the technical details in this book, but I do think there are a number of generalizations in this book that will come in handy as I start to think about the nitty gritty of differences among species in my new home.

For the record I also brought the first volume of Janet Browne’s biography of Charles Darwin Voyaging. I won’t claim that this has done much for my biology, though it is an affecting portrait of biologists. I enjoy both the stories of Darwin as a quirky kid going on natural history expeditions, and the text on Darwin’s worldwide exploration, to localities that include New Zealand. I would guess that I am not the only biologist who sits at a whiteboard/computer screen/thermo cycler and dreams about some hiking trip looking at actual living things. Also any one looking for a last minute Christmas present I still don’t have volume two…

That makes up a snappy list of some of the books that made the cut and are still sitting on my shelf. I think my takeaway is that most things in biology don’t make sense… but some do. Some of the things we learn about biology in one place are worth carting to the far edges of the word. In other cases there is nothing to do but stand back and be amazed at how dramatically different living things are in each new place. Does any one else want to join me in this navel gazing? Which biology books do you guys sling around with you on adventures? Any books that help things make sense? Any one want to make a case that the next time I travel I should ensure I’m carrying a copy of your research with me?

The Kea, the world's only alpine parrot... only in New Zealand

Variation under domestication

When we look to the individuals of the same variety or sub-variety of our older cultivated plants and animals, one of the first points which strikes us, is, that they generally differ much more from each other, than do the individuals of any one species or variety in a state of nature.

Domestic pigeons of the "nun" variety

Domestic pigeons of the variety called "nuns."