Journal tea: A model-based approach for analysis of spatial structure in genetic data

For Wednesday we’ll read:
A model-based approach for analysis of spatial structure in genetic data
by Yang et al.

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arXiving our papers

We’ve just submitted our latest paper to the preprint arXiv (you can read more on the arXiv and its history here). We have done this for every paper we’ve submitted so far as a group; a list of our papers are here. Such preprint archiving is not very common in biology, but is in some other academic communities (notably physics, where the arXiv was established). It is great to see a larger number of quantitative population genetics papers appearing there, hopefully that trend will continue.

Having papers on the arXiv has been a uniformly positive experience:
1) It is great getting comments -from a broad range of people- that you can act on. For example, at least one department is holding a journal club on one of our arXived papers.
2) It is a permanently free copy of our papers. These are available as soon as we’ve written them, instead of after a year (or multi-year) wait that can accompany some iterations of the review process.
3) It is really nice to send someone a manuscript and not have to tell them to keep it to themselves, which always seemed slightly silly to me.
4) People can cite our papers and write blog posts about our papers, e.g. as people have done about our latest paper (Blog posts: here, here, here and here). I’ll hopefully write one shortly about it.
5) It is fun that previous versions of our papers are available (often corresponding to previous journal submissions). That allows people to look back on previous versions and see how our arguments have changed in response to criticism and review. I suspect no one will care to do so with our articles, but it would be great if we could look back at the different versions of now famous articles.
I’m sure there are a tonne of other reasons, but these are the ones that spring to mind.

I, and I’m sure other people, have worried about being scooped and beaten to publication due our arXived papers. But really this is silly as we’ve usually given talks, posters, etc on them at big conferences, so the idea that people somehow don’t know about our work before it appears in print is ridiculous. It is far better to get work out, once you consider it worthy of publication, so it can be read and cited by others.

We will continue to submit our papers there. I’m not sure what we’ll do with papers that don’t fit that criteria of the quantitative biology arXiv, as Nature proceedings shut up shop. But I’m sure we’ll work something out, and we’ll continue to explore other ways to have an open dialog about our work.

[UPDATE] should have noted that the inspiration for this post was seeing discussion by @mbeisen and @joe_pickrell.

[UPDATE 2]
A resource to find what journals permit preprint archiving.
Discussion of ESA’s negative policy on preprint archiving.

[Update 3]
Another biology blog on the joys of ArXiv http://ivory.idyll.org/blog/science-f-yeah.html

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journal tea

For Wednesday we’ll read:
The Limits to Parapatric Speciation: Dobzhansky–Muller Incompatibilities in a Continent–Island Model by Bank et al.

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Back from our grand European tour

We are all back from our European adventures. Both SMBE and the “Probability, Population genetics and Evolution” meeting at the CIRM were great.

The countryside around the CIRM (near Marseille) was spectacular. One of the afternoons after the talks were done, we went for a hike along the limestone cliffs there (followed by a swim in the med). Some photos are below [thanks to Noemi Kurt for sharing these].

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PDFs of our slides and posters are below, for those of you who missed seeing us there:
Graham’s SMBE poster
Graham’s CIRM talk
Peter’s SMBE poster
Peter’s CIRM talk
Yaniv’s SMBE poster
some of this represents unpublished work, so please treat the results as preliminary.

Yaniv agave a version of this talk at the Evolution meeting. Gideon also talked about his spatial popgen work at this meeting. Gideon’s talk got a nice writeup at the Nothing in Biology Makes Sense blog (they also writeup Carl’s work, which we’ve also helped out with a bit [see here]). Thanks to them for a nice writeups.

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Partial sweeps paper out.

Peter Ralph and I’s new paper generalizing the model of recurrent hitchhiking was just accepted to Genetics, and appears as a preprint there (it’s also posted on the ArXiv).

My slides on this topic provide an overview on this work. Below is a brief description of the work, see the paper for references and more.

There is now good evidence that linked selection plays an important role in shaping patterns of genetic diversity in many of the species examined to date. For example, levels of diversity are lower in regions of low recombination and near genes, which is exactly where linked selection should be more prevalent. However, current models of linked selection are often overly simplistic. For example, the dominant model of positive linked selection — the recurrent full sweep model — assumes that all selected alleles sweep rapidly to fixation. While this may be true of some sweeps, due to changing external and genomic environments many selected alleles may sweep into the population but not be destined for rapid fixation.

Peter and I show that these models can be generalized, as in large populations only the initial fast behavior of selected alleles affects the coalescent at partially linked sites. We develop a flexible model of selective sweeps in a multiple coalescent framework, and show that sweeps to intermediate frequencies can have a profound effect on levels of diversity, but can strongly modify other predictions of the hitchhiking model.

These results suggest that one promising way forward is to estimate the distribution of multiple merger sizes in the coalescent. We are now working on inference machinery to this end, and extending our results to soft sweeps.

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Summer travels

Off to Europe!

Peter Ralph and I will be attending the CIRM Probability, Population Genetics, and Evolution meeting. Then Yaniv, Alisa, Peter, and I will be at SMBE. Later on Yaniv will be at the Evolution meeting. We are looking forward to seeing some of you at these meetings. Wishing you all safe and fun summers.

Coop Lab.

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BAPG at UCDavis podcasts

On Saturday we had a great turn out at the sixth Bay area population genomics (BAPG) meeting, which the Coop lab hosted at UC Davis. Over 70 people attended, and we had a great range of posters and talks. Thanks again to the Center for Population Biology and the Graduate group for Population Biology for sponsoring the event. Yaniv, Alisa, Peter and Jeremy put in lots of work to make the meeting a success.

Also thanks to Peter and Alisa for the birthday cake for Yaniv and I’s birthdays. Two of the cakes were decorated with flower petals to represent a crossover and hybrid zone. Sadly we didn’t get pictures of the cakes as they were eaten rapidly (and we were too busy making bad jokes about crossover resolution and the collapse of hybrid zones).

In case you couldn’t attend the podcasts and pdfs of the talk slides are below. Thanks again to the speakers for a great meeting, and for allowing us to share their talks. Luckily we didn’t record everyone singing Happy Birthday to Yaniv and I.

10:00 Ethan Jewett. Using a deterministic function to derive approximate coalescent distributions (Grad Student. Rosenberg lab, Stanford) pdf and podcast

10:30 Yaniv Brandvain. Identification of ancestral haplotypes reveals the history of the selfing species, Capsela rubella. (Postdoc, Coop Lab. UC Davis) pdf and podcast

11:30 Benjamin Peter Which way did they go? Detecting directional migration from genetic data (Grad Student, Slatkin/Nielsen Labs. UC Berkeley) pdf and podcast

12:00 Tanja Pyhäjärvi Complex patterns of local adaptation in teosinte (Postdoc, Ross-Ibarra Lab, UC Davis) pdf and podcast

1:30 Sara Sheehan Estimating ancient population sizes using the coalescent with recombination (Grad Student. Song Lab. UC Berkeley) pdf and podcast

2:00 Alan Bergland Temporal and spatial dynamics of adaptation in Drosophila (Postdoc, Petrov Lab, Stanford) pdf and podcast

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Journal tea: May 21st

We read:
Butterfly genome reveals promiscuous exchange of mimicry adaptations among species

which was a potentially neat paper, but we were unsure whether it was really introgression of the mimcry genes or maintenance of trans-population/species polymorphism by balancing selection.

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BAPG schedule

BAPG VI

SATURDAY MAY 26th 9:00 am – 4:00 pm


1322 Storer Hall, UC Davis

9:00-10:00 – Morning reception and poster set-up, Coffee, and snacks provided

10:00-11:00 – Talks (20 min each. 10 min for questions / discussion)

10:00 Ethan Jewett. Using deterministic functions to derive approximate coalescent distributions (Grad Student. Rosenberg lab, Stanford)

10:30 Yaniv Brandvain. Identification of ancestral haplotypes reveals the history of the selfing species, Capsela rubella. (Postdoc, Coop Lab. UC Davis)

11:00-11:30 – Break

11:30-12:30 – Talks (20 min each. 10 min for questions / discussion)

11:30 Benjamin Peter Which way did they go? Detecting directional migration from genetic data (Grad Student, Slatkin/Nielsen Labs. UC Berkeley)

12:00 Tanja Pyhäjärvi Complex patterns of local adaptation in teosinte (Postdoc, Ross-Ibarra Lab, UC Davis)

12:30-1:30 – Lunch and Poster session

1:30-2:30 – Talks (20 min each. 10 min for questions / discussion)

1:30 Sara Sheehan Estimating ancient population sizes using the coalescent with recombination (Grad Student. Song Lab. UC Berkeley)

2:00 Alan Bergland Temporal and spatial dynamics of adaptation in Drosophila (Postdoc, Petrov Lab, Stanford)

2:30-4:00 – Hangin out. The return Amtrak train to East Bay at 3.50 from Davis.

TRANSPORTATION

AMTRAK to Davis

http://www.capitolcorridor.org/

Morning: Eastward bound Weekend schedule, the best train is #720:

7.34am Berkeley (University and 4th st)

7.42am Richmond (next to BART)

arrives in Davis at 8.52

Storer Hall is just a ~15 min walk from the train station: down 2nd and straight on through campus, by the Quad, then just across California Ave, behind Hutchinson.

Hang out with the other popgen folks in the last car. Bikes are permitted.

Return: 3.50pm train from Davis,

DRIVING From Bay area

Take the I-80 East, merge onto the 113N (to Woodland) at exit 70 (one after Kidwell rd exit)

Take exit 27 to UC Davis, turn right onto Hutchison Rd. Turn left onto Kleiber Hall drive. As you approach the gate, Storer Hall will be to your right.

Parking will be free in the lot to your left.

Storer hall on a campus map:

http://campusmap.ucdavis.edu/?b=145

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the coalescent for generalized models of selective sweeps

We’ve just resubmitted our article on the coalescent for generalized selective sweeps to Genetics. I’ve posted the new version to the arXiv.

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