The Molecular Ecologist: Fishing for genetic signals of adaptation

Atlantic Salmon

Adult Atlantic salmon. (Flickr: Matt Hintsa)

Over at The Molecular Ecologist, I discuss a new paper that exemplifies how we’re going to be studying the genetics of adaptation in the age of high-throughput DNA sequencing—even if it doesn’t quite live up to that promise. It’s a study of adaptation in Atlantic salmon, whose lifestyle makes them uniquely suitable for a particuar sampling design:

Salmon hatch in freshwater rivers, and spend at least their first year in that environment before swimming downstream to the ocean, where they develop into reproductively mature adults. When they’re ready to mate, they migrate back from the ocean, up the river where they hatched to spawn at the site of their birth. Those major migrations and the transitions between freshwater and salt-water are likely to be major selective events for salmon, and they offer convenient times to catch and study salmon from roughly the same age-cohort: when they migrate downstream to the ocean, and when they return to their birth-river.

By taking genetic samples of juvenile salmon on their way out to sea, and then adults on swimming upstream to breed, you can test for genetic changes—adaptation—that has occurred over the course of the fishes’ life in the ocean. And that’s exactly what the authors of this paper did—go read the whole post to find out how it worked.

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Proposed: A new gender-parity benchmark, you guys!

So Science, that lovable institutional behemoth of scientific publishing, has just produced a list of “top 50 science stars of Twitter” that manages to contain, by my count—I’ve triple-checked—four women. Eight percent.

Looking at the list, it hit me:

Seriously, though, I was in a gay bar this weekend with a better gender ratio than @sciencemagazine’s Twitter list: http://news.sciencemag.org/scientific-community/2014/09/top-50-science-stars-twitter#full-list
@JBYoder, 7:50 AM – 17 Sep 2014.

I hereby propose this as a new, painfully minimum standard for gender parity: If I passed more women on a trip between the dance floor and the bar at the Saloon last weekend than are present in your speaker roster, reviewer panel, or unasked-for list of notables, you’re doing it wrong. In the interest of establishing this as a rigorous benchmark, I plan to immediately embark on a systematic survey of gay bar gender ratios, starting Friday night; interested collaborators should contact me through the usual channels.

Meanwhile, see the totally meaningful list of awesome animals Tom Houslay offers in the spirit of Science, and the big special issue on diversity in science just released by that other beloved institutional behemoth of scientific publishing, Nature.

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Nothing in Biology Makes Sense: The key to a secure global future is evolution

Sunrise from the Fall River Road

A mountain vista in Colorado, with trees killed by pine beetles in the foreground. (Flickr: John B. Kalla)

Over at Nothing in Biology Makes Sense, I discuss a big new review article on all the ways understanding evolutionary biology will be critical for human health and development in the next hundred years:

The long list of authors, led by Scott P. Carroll and including Ford Denison, whose lab is just down the hall from my office at the University of Minnesota, explicitly connect evolutionary principles to global goals for sustainable development. These include the reduction of both “chronic lifestyle” diseases and infectious diseases, establishment of food and water security, clean energy, and maintenance of healthy ecosystems. Carroll and his coauthors divide the applications of evolution to these problems into cases where evolution is the problem, and those where evolution may offer the solution.

I’m going to be citing this paper in every grant application I write for the next decade, I suspect. Go read the whole post, and download the original article from Science Express.

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Stuff online, leftovers and lactation edition

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Stuff online, funny five fingers edition

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Stuff online, LED at the end of the tunnel edition

Light Bulb

So long, farewell, auf wiedersehen … Photo by Antony Storo

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Stuff online, untrammeled woodrat guts edition

2006.07.10 - St. Mary's Lake

Still worth it.

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Stuff online, vampire barnacles edition

Seawall along Burrard Inlet

Every recommended route through Vancouver will go through Stanley Park. Photo by Christopher Porter.

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Chris Smith takes on that Troublesome book

Cain and Abel

Cain and Abel, in medieval stained glass. Photo by Fr Lawrence Lew.

Over at Nothing in Biology Makes Sense, Chris Smith has been writing a series of posts digging deep into the evolutionary claims made in Nicholas Wade’s book A Troublesome Inheritance. Last week, Chris debunked the claim that human population genetics naturally sorts into “races”—this week, he’s taking on Wade’s claim that variation at a particular gene has made some human populations more prone to violence than others:

Although some studies have found genetic variants in the MAO-A promoter region that are more common in some ethnic groups than in others (Sabol et al. 1998; Widom & Brzustowicz 2006; Reti et al. 2011) it is likely that these genetic variants are not –on their own– associated with violent or impulsive behavior (Caspi et al. 2002; Widom & Brzustowicz 2006). Instead, genetic variation in the MAO-A promoter seems to make some children less able to recover from abuse and childhood trauma, and therefore more likely to act out later in life (Caspi et al. 2002; Widom & Brzustowicz 2006). Simply carrying the ‘low expression’ allele in the MAO-A promoter does not have any effect at all on impulsivity or aggression.

Chris co-teaches a class on exactly the topics covered in A Troublesome Inheritance, so I highly recommend you read the whole thing, and follow the series to its conclusion.

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