Jared Grummer recently returned from a field expedition to a Liolaemus lizard hybrid zone in Argentina. This is part of his dissertation research aimed at studying speciation in the group. You can read a full report on his field expedition at the Burke Museum blog. It contains a lot of photos of interesting looking lizards. Some of the lizards look suspiciously similar to Sceloporus.
Liolaemus melanops relaxing in the shade. Photo by Jared Grummer
We received some exciting news from NSF! Jared, Matt, and Rebecca each got their NSF-DDIG grants funded this year! Matt and Jared applied to the Phylogenetic Systematics program, and they just heard the good news today. Rebecca submitted to the Evolutionary Genetics program, and she got the news last week. We are extremely grateful to NSF for their support!
Rebecca Harris: Investigating the genomic structure of speciation: a comparative approach using wagtails (Aves: Motacilla).
Matt McElroy: Comparative phylogeography and thermal ecology of Puerto Rican anoles.
Jared Grummer: Hybrid zone formation and comparative genomic divergences in South American lizards (Iguania: Liolaemidae).
Matt McElroy received the 3rd annual Raymond B. Huey Award for the best student presentation at the Society for Integrative and Comparative Biology (SICB) meeting. The competition is open to graduate students who are presenting independent research in ecology and evolution. Matt presented his dissertation work on thermal adaptation in Puerto Rican Anolis lizards. Congratulations Matt!
You can read more about Matt’s current research at the Science Positive Blog where Matt just posted some “Notes from the field”.
Recording body temperature from an Anolis lizard.
More on Matt’s Research: Matt tested predictions from the Bogert Effect, a classic hypothesis described by Ray Huey, Paul Hertz, and Barry Sinervo (Huey et al., 2003). The Bogert Effect describes how thermoregulatory behaviors may buffer natural selection acting on thermal physiology. Thermoregulating species are able to maintain specific body temperatures despite inhabiting different thermal environments. The Bogert Effect predicts that gene flow should be high – and divergent natural selection weak – for populations of thermoregulating species that span a thermal gradient. Matt tested these predictions in Anolis cristatellus, a thermoregulating species that inhabitats a range of thermal environments on Puerto Rico, including a xeric and hot scrub forest in the Southwest. Matt collected genetic data both island-wide, and along elevational gradients, and found support for a genetically distinct population in the SW that correlates with the xeric scrub forest. Matt also found that genes flow out of the SW xeric forest, and from low to high elevations, but not the other way around. These results are surprising, because the Bogert Effect predicts that there should be bi-directional gene flow between xeric and mesic populations of lizard. These results indicate that there may be strong selection against cool-adapted individuals in warm habitats, but only weak selection against warm-adapted individuals in cool habitats. Therefore, selection on physiological traits may play an important role in generating and maintaining diversity in tropical ectotherms. Furthermore, these results have important implications for conservation, as locally adapted populations in the xeric SW may become a source for adaptive alleles during global climate change.
Cilia & Emy
We recently hosted our friends from Greece, Dr. Cilia Antoniou from the Institute of Marine Biology, Biotechnology and Aquaculture (IMBBC) and the Hellenic Centre for Marine Research (HCMR), and Emy Karameta from the University of Athens. They visited the lab for a few weeks to collect SNP data for their phylogeography and species delimitation projects focusing on taxa found in the beautiful Aegean Islands. Cilia and Emy are instructors at the annual Computational Molecular Evolution Workshop. Emy is studying agama lizards (Stellagama stellio) in the Mediterranean as well as the phylogeography of other co-distributed species found across the Islands. Cilia is studying a wide variety of taxa, including hares (not rabbits), dolphins, and even land snails. We’re looking forward to seeing them again in the UK in 2015, and then visiting them on their home turf in Crete in 2016.
A new paper published in the journal Molecular Phylogenetics & Evolution contains a new recipe for making phylogenetic sausage,
“We suggest that the coalescence protocol utilized by McCormack et al. (2012) is the equivalent of making phylogenetic sausage. In the messy construction of a sausage, a butcher grinds together chunks of undesirable cuts (e.g., lips, heart valves, assorted fatty bits, etc.), mixes this flotsam with spices, forcibly extrudes the concoction into a casing made of intestinal lining, and forms a product of passable palatability. Likewise, in the first step of the shortcut coalescence procedure, undesirable gene trees were reconstructed from small, uninformative bits of the genome (Fig. 7; Table 1) that in some cases have wildly varying rates of evolution in different mammalian lineages (Fig. 10). The arbitrarily resolved, inaccurate gene trees were then forced into a final species tree casing under the assumption that all gene tree conflicts are due to deep coalescence. Utilizing this crude and messy process, a phylogenetic hypothesis.”
–Gatesy & Springer 2014. Phylogenetic analysis at deep timescales: Unreliable gene trees, bypassed hidden support, and the coalescence/concatalescence conundrum. Molecular Phylogenetics & Evolution 80, 231-266.
I applaud the authors for their novel contribution of a phylogenetic sausage recipe.
If it’s not too late, then perhaps the journal could use one of these possible cover images:
Cover Submission V.2: Rooted 3-taxa Phylogenetic Sausage Tree
Cover Submission V.1: Unrooted 4-taxa Phylogenetic Sausage Tree