Living at the edge, range expansion is a losing battle with mutations

Environments can vary substantially in habitat quality, local population abundance, or carrying capacity. Under some climate change scenarios, new, higher quality habitats become available along the margin of a species’ range (e.g. higher latitudes or altitudes) (Thomas et al 2001). These new habitats may be able to support larger population sizes. Factors of demography, evolution, and qualities of the abiotic and biotic communities all interact to determine where a species is found and may influence the ability of a species to expand its range. New research is building genetically explicit models in order to understand how the interplay of these different factors influence evolutionary changes,

Wordle of Peischl et al 2013

The authors of a recent study focus on how the interaction of the demographic process of range expansion changes the way that natural selection favors beneficial and deleterious mutations (Peischl et al 2013). Using both computer simulations as well as mathematical approximations, the authors find that at the range margins, individuals carry a substantial load of deleterious mutations.

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The 23 chromosomes (and one organelle) of Christmas

Via Joe Hansen: the Royal Institute is celebrating the season with an online Advent calendar in which they “unwrap” the biology of one human chromosome, and the mitochondrion, each day until Christmas. Here’s today’s entry on chromosome 2, which tackles the genetic differences between humans and chimps:

Research and teaching postdoc in the population genomics of mutualism

2010.04.05 - Samson out and about

One of your future colleagues in the Smith Lab, hard at work in the field.

Friend of the blog—and longtime collaborator of mine—Chris Smith recently landed an NSF CAREER grant for new research on the causes of evolutionary divergence within the Joshua tree-yucca moth mutualism—and he’s looking for a postdoc to help with it!

The proposed work will take advantage of new genomic resources for the genus Yucca—Joshua tree population genetics is about to get a lot more powerful than the 10 microsatellite loci I used for my dissertation research. And it will involve fieldwork in the Mojave Desert, which is objectively one of the most beautiful empty spaces on the map of North America. Chris is on the faculty of Willamette University, which is an undergraduate institution, so the postdoc position is also a unique opportunity to do basic research in close coordination with an undergraduate teaching program.

Moreover, I can personally recommend Chris as a mentor and collaborator—to the extent that I’ve turned out to be a pretty decent scientist, he’s one of the principal reasons why. (And to the extent that I haven’t, well, that’s a reflection on me, not him.)

The complete job description, and instructions on how to apply, are after the jump.

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Better know your bacon: the evolutionary history of the genus Sus.

Wild Boar In Snow

It would seem that between the global hitchhiking of feral pigs with human migration, America’s absurd obsession with bacon and the possible emergence of pandemic influenza via recombination of human and porcine strains, the past, present and future of our civilization are inextricably linked to that of the domestic pig. With that in mind, let’s have a look at a recent paper on the evolutionary history of the genus Sus by Frantz et al. 2013.

Domestic pigs are in the family Suidae, which includes the babirusas, warthogs, the endangered pygmy hog (whose generic name is, Porcula, seems a likely candidate for America’s next tragic children’s cereal) and the domestic pig’s close relatives in the genus Sus. Depending on where you draw the lines, there are around 7 species in Sus. With the exception of the wild boar (Sus scrofa) their natural ranges are restricted to Southeast Asia west of Wallace’s Line. Extant species of Sus have diversified recently (sharing a common ancestor ~5 million years ago) and the species are all thought capable of producing viable hybrid offspring. Most species are restricted to single islands or island complexes in Southeast Asia (such as Borneo, Java and the Philippines). Previous phylogenetic estimates of the genus are in conflict over the relationships among species.

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Postdoc in evolutionary genetics of complex traits

2012.10.22 - Medicago truncatula

Do you like evolution, genetics, and evolutionary genetics? Would you like to think of things to do with a whole lot of genetic data and a flagship model legume? Well, my boss, Peter Tiffin, is looking for another postdoc. Here’s the post description from EvolDir:

I have available a post-doctoral position to work on association and evolutionary genomics of the model legume Medicago truncatula. Collaborators and I have recently collected genome sequence for > 200 accessions and have used these data for GWAS and population genomic analyses. We are currently working to refine our understanding of genomic variation segregating within this species and are particularly interested in the evolutionary genetics of the symbiosis between Medicago and Sinorhizobia. The successful applicant will have considerable freedom to develop research in their area of interest.

The deadline for submissions is 15 September 2013, so get in touch with Peter pronto if you’re interested. (See the full ad for contact information and the application package requirements—it’s standard stuff.) Benefits of the position include working with population genomic data from the cutting edge of current technology in a collegial lab with some very smart people (and me) in the midst of a fantastic community of biologists at the University of Minnesota—as well as living in the Twin Cities, which are empirically awesome. Yes, even in winter.

Who are the people in your neighborhood, Baba Brinkman?

Baba Brinkman’s latest salvo in his quest for a fact-based justification for his proposal to select meanness out of the human race by not sleeping with it really boils down to a question most members of my generation will likely remember from a childhood saturated in “Sesame Street”: Who are the people in your neighborhood?

We’ve come to this question because Brinkman has finally discovered that there is, in fact, data that might suggest genetic variation contributes to variation in “meanness”—even if he couldn’t be bothered to cite it in connection with the campaign up to now:

In his new post, Yoder’s argument is not that male violence isn’t an adaptation; rather, he argues that our violent tendencies have been so completely drilled into us by natural selection that they show insufficient genetic variation for selection to act on …

He’s right that a complete lack of individual genetic differences in proneness-to-violence would be a death-blow for my campaign, but luckily for me and all the other peaceniks who support the DSWMP credo, Yoder simply didn’t bother to look up any of the evidence.

You have to love how, after implicitly conceding the factual point—that in his first attempt to shore up the scientific basis of DSWMP, he cited data that has nothing to do with the question at hand—Brinkman chides me for not doing my homework. In fact I’ve acknowledged at every step of our little back-and-forth that there is a body of research which suggests there’s some genetic contribution to variation in what we might call “meanness.” My argument isn’t that this genetic contribution doesn’t exist—it’s that this genetic contribution is pretty much meaningless from the perspective of an individual person’s dating life.

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Baba Brinkman says he wants my money

But he doesn’t want it badly enough to actually address the substance of any of my criticisms of his scheme to rid the world of meanness via “an entirely defensible ‘bottom up’ form of eugenics.”

Oh, and I see he’s speculating about my sex life. Real charmer, this guy.

In his non-response response, Brinkman doubles down on his fixation with the fact that, across human populations, males become more likely to be involved in violent crime right around the time we hit puberty:

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Inane pseudo-scientific claptrap of the week: “Don’t sleep with mean people”

The maestro behind the “Rap Guide to Evolution,” Baba Brinkman, has a new idea for changing the world: don’t sleep with mean people. I know, right? You hadn’t thought about doing that, either?

Are you amazed at the clarity of Brinkman’s insight into the roots of human suffering? Then he would like you to give him money to help make his plan a reality. Well, to make a music video and a documentary and some billboards, anyway.

Or, you know, you could do something more useful with your money, like baking it into muffins as a fiber supplement. Or shredding it up to mulch your vegetable garden. Or using it to line a bird cage.

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@NothingInBio at #Evol2013: What we’re presenting

Cecret Lake - Alta Utah

The Evolution 2013 meetings are nearly upon us, and most of the team here at Nothing in Biology Makes Sense! are going to be in Snowbird, Utah for the joint annual meeting of the American Society of Naturalists, the Society of Systematic Biologists, and the Society for the Study of Evolution. Rather than make you hunt through the online program, here’s where we’ll be, and what we’re presenting:

  • Amy will present “The population genetics of rapidly evolving reproductive genes: How much variation should we expect to find?” on Sunday at 9:30, as part of the Evolutionary Genetics and/or Genomics section in Cotton D/Snowbird Center. [program link]
  • Look for some of CJ’s work in a lightning talk by her dissertation advisor, Mark Dybdahl, titled “Identifying the molecular basis of coevolution: merging models and mechanisms” on Monday at 11:45, in Superior B/Cliff Lodge. [program link]
  • Noah will present “What can we learn from sequence-based species discovery? An example using sky island fly communities” on Tuesday at 9:30, as part of the Community Ecology and Evolution section in Peruvian A/Snowbird Center. [program link]
  • Sarah will present “Nature, nurture and the gut microbiota in the brood parasitic Brown-headed Cowbird” on Tuesday at 10:30, as part of the Community Ecology and Evolution section in Peruvian A/Snowbird Center. [program link]
  • Jeremy will present “Evidence for recent adaptation in genome regions associated with ecological traits in Medicago truncatula” on Tuesday at 2:45, as part of the Genetics of Adaptation section in Rendezvous A/Snowbird Center. [program link]

Looks like we’re in for a busy Tuesday! But this year, you won’t have to choose between us.

Roller derby is like giant hug with every girl on the track: swapping microbes due to contact

Often I think we as scientist do a really good job of convincing ourselves that our work is important. However, our research rarely makes a big enough splash that a study is widely accepted by everyone as awesome. Trust me, I have recently tried to excitedly explain to a non scientist at a party why finding the recessive mutation behind disliking cilantro was sooooo cool. It didn’t work…

But this study is so cool that it has already blown up the blogosphere. So much so that I was considering posting on an awesome new review by two of my favorite researchers out of the UK (if you haven’t read this yet you should. Also check out Britt Koskella’s blog… it’s pretty awesome). But being a roller derby skater myself (Rolling Hills Derby Dames), I decided I couldn’t let such an awesome study go by without posting about it.

At the moment, the field of microbial ecology is going from big to huge. This is partially due to the inexpensive availability of genome data making it possible to asses the frequency and species of microbes within all sorts of environments. It could also be due to the immediate applicability to human health, as the composition of the microbiome has been linked to obesity, bacterial vaginosis and potentially irritable bowel syndrome.

These communities vary across different parts of the body and individuals, and change over time. And although we know quite a bit about how pathogens can be passed from person to person due to contact, not much is known about the effect contact has on the microbiome.

Lots of contact. Photo Credits to Scott Butner

Lots of contact.
Photo Credits to Scott Butner

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