Graduate News

Heliconius hecale (Tiger Longwing) captive by S. Rae, Edinburgh Butterfly & Insect World on Flickr

Study Reveals Speciation More Complicated Than Imagined

November 1, 2019

 

Jim Mallet and PhD students Nate Edelman (Mallet Lab) and Michael Miyagi (Desai & Wakeley Labs) have found evidence for widespread hybridization and gene flow between different species of Heliconius butterflies. The team looked at a group of neotropical butterflies and found that different species have been hybridizing with each other throughout their millions-of-years-old history. They developed a new method to identify parts of the genome that were particularly impacted by hybridization and showed the process of recombination is widespread and important to the...

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Roopkund Lake-Figure 1. Photo by Atish Waghwase

Ancient DNA Reveals Mediterranean Migrants in India

August 20, 2019

Roopkund Lake is a small body of water nestled deep in the Himalayan mountains. The Lake is known colloquially as Skeleton Lake due to the remains of several hundred ancient human scattered around its shores. The skeletons have never been studied so little was known of the origins. 

Graduate student, Eadaoin Harney (Wakeley Lab) and researchers analyzed the remains using bioarcheological analyses (including ancient DNA, radiocarbon dating, stable isotope dietary reconstruction and osteological analysis) and discovered three genetically distinct groups...

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Belugas in Water with Topography of Animals Ridges

How Smooth Is A Dolphin?

July 17, 2019

Dolphin skin has long inspired research on drag reduction mechanisms due to the presence of skin ridges that could reduce fluid resistance. Prof. George Lauder and PhD student, Dylan Wainwright (Lauder Lab) collected in vivo three-dimensional surface data on the skin from five species of odontocetes (cetaceans that includes dolphins, porpoises, and all other whales possessing teeth) to quantitatively examine skin texture, including the presence and size of ridges.

Lauder, Wainwright and team molded the skin of live...

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Eggs by Nicholas Blumhardt on Flickr

Overturning Evolutionary Doctrine

July 3, 2019

In a new study in Nature, Cassandra Extavour and her lab disprove an old hypothesis and prove a new one. Extavour says insects make up 80 percent of all animal species on Earth. She and PhD students, Sam Church, Seth Donoughe ('18), and Bruno de Medeiros analyzed a large data set to challenge the untested assumptions about egg size in insects. Across all insects, the team found...

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European roe deer courtesy of Nathan Ranc

From One Animal to an Ecosystem

June 21, 2019

At 45 pounds and just over two feet tall, adult European roe deer are much smaller than American deer and closer in size to a greyhound. And unlike their cousin species, red deer or elk, roe deer like to be solitary, spending most of their lives within a range of one square kilometer.  PhD student, Nathan Ranc (Paul Moorcroft lab) want to know the reason for this mystery. In the Alps of northern Italy, Nathan and colleagues are trying to build a model that explains the factors determining why particular deer choose to live where they do. His work with roe deer...

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Illustrations for McCoy Proceedings of Royal Society B Paper

Structurally Assisted Super Black in Colourful Peacock Spiders

May 15, 2019

Peacock spiders, known for their elaborate mating dances, use incredibly dark, “super black” patches on their body to enhance nearby colors. This makes colors look impossibly bright, or even glowing, an optical illusion also used by birds-of-paradise.The spider evolved microlenses on its body surface, which manipulate light in the same way human-made materials do.

PhD Student, Dakota McCoy (David Haig Lab) documents a remarkable convergence of form, between nature and engineering, and function, between two groups of highly ornate, sexually selected animals,...

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southern cassowary Luke Seitz

Convergent Regulatory Evolution and Loss of Flight in Paleognathous Birds

April 5, 2019

Species from widely divergent taxa can experience similar changes in traits. What underlying genetic drivers cause these parallel changes remains an open question. Scott Edwards, Tim Sackton (Director of Bioinformatics and former Postdoc) and PhD student Phil Grayson used a new method developed by collaborators in the Harvard Statistics Department to look across groups of birds that have repeatedly lost flight. The team showed there is convergence in the regulatory regions associated with genes related to flight, but not within the protein coding regions.

In the...

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