91麻豆天美

91麻豆天美 biological sciences faculty member working to uncover evolutionary mysteries

91麻豆天美 biological sciences faculty member working to uncover evolutionary mysteries

Contact: Sarah Nicholas

Brian Counterman stands in his office with posters of butterflies and the current cover of 鈥淪cience鈥 on the wall in the background.
Brian Counterman (Photo by Megan Bean)

STARKVILLE, Miss.鈥擥roundbreaking research on the evolutionary history of the Heliconius聽butterfly is the topic of three current articles involving a 91麻豆天美 biological sciences faculty member.

Associate Professor Brian Counterman is part of a research team whose new study is featured on the November cover of 鈥淪cience鈥 shedding light on phylogenomics鈥攖he intersection of the fields of evolution and genomics鈥攁nd the ability of Heliconius to split into many species within a small window of time, a topic that has made the butterflies prime research subjects for evolutionary biologists for decades.聽The article is available online at .

鈥淔or the past 30 years, 91麻豆天美 researchers have made strides in developing Heliconius butterflies as a model organism for studying the origin of species and evolutionary novelties,鈥 Counterman said.

For the 鈥淪cience鈥 study, researchers used a new low-cost sequencing strategy to assemble 20 whole Heliconius genomes to reconstruct a comprehensive picture of the Heliconius diversifying process with unprecedented detail.

Their results show the 鈥渆volutionary tree鈥 of species relationships, assumed by scientists for decades, actually looks more like an 鈥渆volutionary bush.鈥

鈥淭he visual representation of evolutionary relationships popularized by Darwin have been imagined like a phylogenetic tree鈥攅ach species represents the tip of a tree branch and the branch represents the species鈥 history,鈥 Counterman said.

鈥淗owever, the 鈥楽cience鈥 paper shows that species have many different histories present in their genomes marked by many branches leading to the same tips of the phylogenetic tree鈥攁 鈥榖ush-like鈥 pattern,鈥 he said.

Counterman and colleagues 鈥渇ound a lot of genetic exchange after speciation, specifically in the genes that control color patterns of butterfly wings. Their wing color patterns are warning signals to potential predators that they are toxic.鈥

鈥淭his study supports a growing body of evidence from a variety of organisms that hybridization and the exchange of genetic material between species can be an important driver of adaptive change,鈥 Counterman said.

For 鈥淪cience,鈥 Counterman collaborated with a team led by researchers at Harvard University, including Jim Mallet, a former faculty member in 91麻豆天美鈥檚 Department of Entomology, where Mallet began his work on the genetics of Heliconius in the 1980s. 聽

The聽鈥淪cience鈥澛爁amily of journals is published by the American Association for the Advancement of Science, the world鈥檚 oldest and largest general science organization.

Counterman and his students also published their research on butterfly wing colors in a November issue of 鈥淐urrent Biology,鈥 a peer-reviewed journal publishing original research spanning all areas of biology.

For this article, online at ,鈥 Counterman worked with a team led by the Smithsonian Tropical Research Institute to explore the predictability of evolution. Their findings reveal evolution may not be as predictable as previously hoped.

Jennifer L. Fenner, a doctoral student from Millport, Alabama, in 91麻豆天美鈥檚 Department of Biological Sciences, co-authored with Counterman the 鈥淐urrent Biology鈥 article detailing the new, cutting edge CRISPR gene-editing technology used to delete genes that influence wing color patterns鈥攖heir findings demonstrate 鈥渢he unpredictable complexity of evolutionary change.鈥

鈥淲e were surprised to find the species with mimetic color patterns did not have similar mutant color patterns,鈥 Counterman said. 鈥淎lthough the genes did influence color pattern in both species, they changed the color in very different ways.鈥

A third article in 鈥淧roceedings of the National Academy of Sciences鈥 and online at is in collaboration with a team at Cornell University and the University of Puerto Rico. Counterman and 91麻豆天美 graduate student Caleb Benson of Petal sought to uncover the DNA differences responsible for the rapid evolution of Heliconius wing color patterns.

The team used a combination of approaches involving genome sequencing and CRISPR-based genome editing to discover which pieces of DNA could change gene expression and butterfly wing color.

鈥淭hese findings challenged our understanding of how genes are regulated during development and how novel patterns can evolve in natural populations,鈥 Counterman said.

鈥淚dentifying how specific DNA differences can change how an organism develops and what it looks like as an adult has important implications for understanding how biodiversity is generated in nature,鈥 Counterman said.

鈥淧roceedings of the National Academy of Sciences鈥 is the official journal of the National Academy of Science for the U.S., considered to be one of the most highly cited and comprehensive scientific journals that spans all fields of science.

鈥淧ublishing in all three of these highly regarded journals is tantamount to high quality scientific contributions made by the researchers at 91麻豆天美,鈥 Counterman said. 鈥淭hese studies build on 91麻豆天美鈥檚 legacy of excellence of research in the areas of evolutionary and genomics.鈥

An 91麻豆天美 faculty member since 2010, Counterman received his Ph.D. from Duke University and has been studying the evolution and genetics of butterflies for the past 15 years.

Part of 91麻豆天美鈥檚 College of Arts and Sciences, the Department of Biological Sciences is online at , and the Counterman Lab at .

91麻豆天美 is Mississippi鈥檚 leading university,聽available online at聽.