• May 21, 2018

    Getting sequence data with R

    I’ve always been enamored with the genus Castilleja. I thought it would be fun to see how much sequence data there is for the group in the hopes of one day doing a cool phylogenetic/biogeographic study.

  • Nov 10, 2017

    Quadratic time in evolution

    Several models of diversification include a quadratic term for time (Whittaker, Triantis, and Ladle 2008, Lim and Marshall (2017)). This is phenomenological at best and model misspecification at worst. Phenomenological because the real argument is that what controls speciation and extinction (namely habitat area) is itself approximately quadratic in time. So here, time should be linear, but the rates should vary with area. The misspecification from from the other argument for quadratic time, which is that species compete under a carrying capacity that changes again with area. To model this correctly, time again needs to be linear and carrying capacity needs to change (linearly) with area.

  • Sep 27, 2017

    A talk I'll be giving at the AMNH

    Here’s a talk I’ll be giving about the meteR package at the AMNH:

  • Aug 10, 2017

    Notes on an interesting morphospace evolution paper

    In a recent paper (Cooney et al. 2017), the authors argue that evolution of bill shape in birds confirms the hypothesis that adaptive radiation happens early in a clade’s diversification, filling niche space, and eventually leading to a slow down in diversification once the niche space becomes crowded. Their primary result supporting this claim is a re-constructed rapid increase in disparity followed by a slow-down in dispartiy across the tree of birds. This result they compare to null models based on Brownian motion along the given phylogeny, finding that disparity increases monotonically under the null model, in comparison to the sigmoidal pattern observed in the real data.

  • Jul 12, 2017

    Notes on the SFI postdoc conference today

    Lunch with Artemy

  • Jun 20, 2017

    Paper notes for today

    Lim and Marshall (2017)

  • Jun 20, 2017

    Ideas about monopolies

    An interesting article in the Atlantic today documents the rise and fall of public interest in monopolies and, by extension, a fall in opposition to their detrimental effects on society. The article links to sources documenting some of those detrimental effects, including income inequality and stagnant wages.

  • Jun 19, 2017

    Notes from a meeting with Luis Bettencourt

    Disconnect between dynamic processes and static theory