Nav: Home

One-of-a-kind? Or not. USU geneticist studies formation of new species

February 17, 2017

LOGAN, UTAH, USA - At what point on the journey along the branches of the evolutionary tree does a population become its own, unique species? And is a species still distinct, if it mates with a different, but closely related species? Evolutionary biologist Zach Gompert of Utah State University explores these questions and more, using plant-eating stick insects of the Timema genus as a research model.

With colleagues from ten universities in North America and Europe, Gompert published ecological and genomic insights into stick insect speciation in the Feb. 17, 2017, issue of Nature Ecology & Evolution. His research is supported by the National Science Foundation and the Division of Research Computing in USU's Office of Research and Graduate Studies.

Timema, commonly known as "walking sticks," are cryptic, meaning they visually blend into their surroundings to hide from hungry predators.

"Our work on these insects suggests speciation can be initiated by a few genetic changes associated with natural selection on cryptic color-patterns," says Gompert, assistant professor in USU's Department of Biology and the USU Ecology Center. "While speciation is much more complicated than these changes, Timema's color-patterns provide a window for studying the early phases of the formation of a species."

For the study, the researchers combined field experiments with genomics. They sequenced more than 1,000 stick insect genomes - the genetic material of each organism. Gompert says the size of their study is a research scale rare outside of human population genetic studies.

"Having sequenced the genomes of a thousand individuals, we were able to pick up signals and variations that might have been missed in a smaller sample," he says.

The overall process of generating a new species involves mate choice and the accumulation of genetic differences across the genome in geographically isolated populations, Gompert says. Rapid reversals of speciation can occur when distinct species, long separated, once again cross paths and mate.

"When you look at places where two populations co-occur, they are either quite distinct across the entire genome or only distinct in a few regions of the genome," he says. "This could be viewed as an evolutionary gap. However, when you look across space, where populations don't co-occur, you can span this gap because intermediate stages of genetic differentiation are observable."

So, what makes a species its own species?

"We still have a lot of unanswered questions," he says. "While color variations in organisms, such as stick insects, can be striking and inform us of phases of evolution, they're one small aspect of a multi-faceted speciation process."
Additional authors on the paper are Rüdiger Riesch of the University of London; Moritz Muschick, University of Bern; Dorothea Lindtke, Romain Villoutreix, Kay Lucek, Elizabeth Hellen, Victor Soria-Carrasco, Clarissa de Carvalho and Patrick Nosil of the University of Sheffield; Aaron Comeault, University of North Carolina, Chapel Hill; Timothy Farkas, University of Connecticut; Stuart Dennis, Eawag Swiss Federal Institute of Aquatic Science and Technology; Rebecca Safran, University of Colorado; Cristina Sandoval, University of California, Santa Barbara; Jeff Feder, Notre Dame University; and Regine Gries, Bernard Crespi and Gerhard Gries of Canada's Simon Fraser University.

Utah State University

Related Evolution Articles:

Genome evolution goes digital
Dr. Alan Herbert from InsideOutBio describes ground-breaking research in a paper published online by Royal Society Open Science.
Paleontology: Experiments in evolution
A new find from Patagonia sheds light on the evolution of large predatory dinosaurs.
A window into evolution
The C4 cycle supercharges photosynthesis and evolved independently more than 62 times.
Is evolution predictable?
An international team of scientists working with Heliconius butterflies at the Smithsonian Tropical Research Institute (STRI) in Panama was faced with a mystery: how do pairs of unrelated butterflies from Peru to Costa Rica evolve nearly the same wing-color patterns over and over again?
Predicting evolution
A new method of 're-barcoding' DNA allows scientists to track rapid evolution in yeast.
Insect evolution: Insect evolution
Scientists at Ludwig-Maximilians-Universitaet (LMU) in Munich have shown that the incidence of midge and fly larvae in amber is far higher than previously thought.
Evolution of aesthetic dentistry
One of the main goals of dental treatment is to mimic teeth and design smiles in the most natural and aesthetic manner, based on the individual and specific needs of the patient.
An evolution in the understanding of evolution
In an open-source research paper, a UVA Engineering professor and her former Ph.D. student share a new, more accurate method for modeling evolutionary change.
Chemical evolution -- One-pot wonder
Before life, there was RNA: Scientists at Ludwig-Maximilians-Universitaet (LMU) in Munich show how the four different letters of this genetic alphabet could be created from simple precursor molecules on early Earth -- under the same environmental conditions.
Catching evolution in the act
Researchers have produced some of the first evidence that shows that artificial selection and natural selection act on the same genes, a hypothesis predicted by Charles Darwin in 1859.
More Evolution News and Evolution Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Clint Smith
The killing of George Floyd by a police officer has sparked massive protests nationwide. This hour, writer and scholar Clint Smith reflects on this moment, through conversation, letters, and poetry.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Producer Tracie Hunte stumbled into a duet between Nina Simone and the sounds of protest outside her apartment. Then she discovered a performance by Nina on April 7, 1968 - three days after the assassination of Dr. Martin Luther King Jr. Tracie talks about what Nina's music, born during another time when our country was facing questions that seemed to have no answer, meant then and why it still resonates today.  Listen to Nina's brother, Samuel Waymon, talk about that April 7th concert here.