• Home
  • Cherry Picked - Researcher asks what makes a species by looking closely at lizards

Researcher asks what makes a species by looking closely at lizards

Tuesday, March 08, 2016

LAWRENCE — With a recent four-year, $600,000 grant from the National Science Foundation, a University of Kansas researcher is undertaking the most-detailed analysis ever carried out of how reptiles branch into various species.

In doing so, Richard Glor, associate professor of ecology and evolutionary biology at KU and associate curator of herpetology at KU’s Biodiversity Institute, is questioning some of the very methods scientists use to define species.

Further, by combining laboratory studies with fieldwork and genomic sequence data, Glor and his team hope to determine the genetic basis for species differences and why these species diverged in the first place.

Glor said biologists traditionally employ the idea of “reproductive isolation,” or the inability of one kind of animal to fruitfully breed with another, to determine boundaries defining individual species.

“Every student in biology has learned the philosophy of what a species is — something that can’t reproduce with other species,” Glor said. “So when someone describes a new species, you’d think they’ve done a bunch of crossing experiments [to see if a species can reproduce with another], but the answer is that nobody ever does that.”

He said more laboratory studies should be conducted to verify assumptions about boundaries between species and less reliance should rest on how animals look to the eye. His new grant is based on the idea that conventional methods have overlooked recent and ongoing speciation events.

“Traditional taxonomists say that if species exhibit differences in their appearance — this one is green, and this one is red — they likely aren't reproducing with one another,” Glor said. “I saw that as an understudied area in speciation research. We always talk about reproductive isolation, but we never test it.”

Glor has revealed this shortcoming in part by conducting crossing experiments on a group of lizards called bark anoles found on Hispaniola, the Caribbean island shared by Haiti and the Dominican Republic. These lizards are notable for the remarkable variation of their “dewlap,” or flap of skin along the throat, that can be found in different colors and patterns.

“The dewlap is colorful, kind of like a fancy car or jewelry in the human population,” Glor said. “It shows the female you’re attractive and helps her recognize her own species, so it’s critical to sexual selection. The group that I study is particularly noteworthy because a single species exhibits very different dewlap colors and patterns (i.e., some populations are yellow, while others are red). Most anole species exhibit only a single color.”

Previous biologists have relied on variation in dewlaps to separate bark anoles into different subspecies.

“When herpetologists drove across Haiti's mountainous Tiburon Peninsula more than 50 years ago, they saw bark anoles with pale yellow dewlaps at the beginning of their journey, bark anoles with orange and then wine red dewlaps further along, and then started seeing bark anoles with pale yellow dewlaps again by the time they reached the far tip of the peninsula,” Glor said. “As a result, they described these populations with different dewlap colors as distinct subspecies.”

But as Glor and his colleagues obtained genomic data from the lizards, they found dewlap colors weren’t a trustworthy sign of the underlying genetic differences scientists expect to find in distinct species.

“These populations don’t seem to be genomically differentiated,” he said. “Some of those taxa that traditional methods show to be different species probably aren’t different species. Natural selection is driving them to have different dewlap color and appearance for reasons not related to them being different species.”

In other cases, Glor said traditional methods missed species that appear to be strongly differentiated genetically because they are nearly impossible to distinguish externally.

Glor’s work represents the most detailed and integrated analysis ever performed on squamate reptiles — a group of almost 10,000 species, including all lizards and snakes. The research will result in the establishment of a new laboratory model organism, the first squamate genome assembled through linkage mapping and the first “estimates of heritability and the genomic basis for phenotypic traits” vital to systematically studying reptiles in general.

Further, the research has resulted in a public exhibit now on display at the KU Museum of Natural History.

Ultimately, however, Glor said that evolution in species is an unending and fluid process that biologists might always struggle to catalogue and measure.

“All of these ideas like reproductive isolation or morphological divergence are all just benchmarks that occur as new species are forming,” he said. “It could be that some species exhibit all these benchmarks, and some display only one or two. The problem identifying species is that we're trying to put discrete start and stop points on a process we know is continuous.”


Graphic: Taxonomic distributions, sampling, and preliminary results. Images illustrate dewlap coloration typical of each of the Hispaniolan taxa assigned to the distichus species group. Shaded regions of the map indicate ranges of subspecies of A. distichus and correspond with the prevailing color of the dewlap in each of these subspecies. Filled black squares indicate sampling localities from which whole animal voucher specimens are available. White squares indicate localities from which tissue samples, whole animal voucher specimens and dewlap photographs are available. Bar graphs were generated by analyses of AFLP loci obtained from 96 individuals sampled from across the range of A. distichus in STRUCTURE and indicate proportion genotypic assignment of each individual to one of five genotypic clusters. Colored circles indicate localities from which AFLP data were obtained, with the color of each circle corresponding with the majority genotype assignment for individuals at a given locality. 

Photo: KU is celebrating 100 years of herpetology research. World-renowned herpetologist Rich Glor is a curator of the collection. Credit: Meg Kumin, KU Marketing Communications.


Read the latest MUSE News!

Find out what KU's Museum Studies Program and our alumni are up to:

September 2017 Newsletter
January 2017 Newsletter
 

 

Museum Events

Art Cart: Painted Fans
Saturday, January 20 | 1 p.m.-4 p.m.
Spencer Museum of Art, Sam and Connie Perkins Central Court, 317
1301 Mississippi St.
The Art Cart is a drop-in activity station where children and grown-ups enjoy hands-on art projects together, taking inspiration from original works of art. After traveling the world, Sallie Casey Thayer donated her collection of objects to KU to form what is now the Spencer Museum of Art. Learn about Mrs. Thayer and create a painted folding fan to start your own collection.

Slow Art Sunday: Steel Wool Peignoir
Sunday, January 21 | 2 p.m.-3 p.m.
Spencer Museum of Art, Kemper Family Foundations Balcony, 408
1301 Mississippi St.
Slow down at the Spencer and spend time getting to know one great work of art. Slow Art Sunday features one work for visitors to contemplate and converse about with Museum staff. In January, get to know Steel Wool Peignoir by Mimi Smith.

Science on Tap: The Cambrian: More than just Trilobites
Wednesday, January 24 | 7:30 p.m.
Free State Brewing Co., 636 Massachusetts St.
The Cambrian is a time in Earth’s history when many modern animal relatives make their first appearance. It is also a time when many bizarre animals without modern relatives appear in the fossil record. At this Science on Tap, Dr. Julien Kimmig will talk about the diversity of animals during this amazing period and what it can teach us about the future of life on earth. 

Career Close-ups: Developing a Career in the Museum World
Friday, January 26 | 2 p.m.-4 p.m.
Spencer Museum of Art, Auditorium 309
1301 Mississippi St.
Undergraduate and graduate students are invited to explore how any major can lead to a career in a cultural organization. A panel of museum professionals will share their experiences, followed by a networking reception and behind-the-scenes tours of KU’s museums. This year’s panelists include: Dina Bennett (Mulvane Art Museum, Washburn University), Glenn North (Black Archives of Mid-America), and Adrianne Russell (Cabinet of Curiosities). Advance registration is required at www.spencerart.ku.edu/career-closeups. Please register by January 24. Facebook page: https://www.facebook.com/events/476618689399321/
Sponsored by the Spencer Museum of Art, KU Natural History Museum, University Career Center, and the Museum Studies Program.

Final Friday: Community and Culture Closing Celebration
Friday, January 26 | 6 p.m.-7:30 p.m.
Watkins Museum of History, 1047 Massachusetts St.
The Watkins, in partnership with the Max Kade Center and the Lawrence Opera Theatre, present an evening of 19th-century German-American music and cuisine.

Discovery Day: Celebrating Kansas
Sunday, January 28 | 1 p.m.-3 p.m.
KU Natural History Museum, 1345 Jayhawk Blvd.
In honor of Kansas Day, join us for hands-on activities that are all about Kansas wildlife, plants and fossils. 

Kenneth A. Spencer Lecture: An Evening with Eve L. Ewing: Poetry in Context
Wednesday, January 31 | 7 p.m.-8:30 p.m.
Liberty Hall, 644 Massachusetts St.
Eve L. Ewing is a sociologist, poet, essayist, artist, and educator whose research focuses on racism, social inequality, urban policy, and the impact of these forces on American public schools and the lives of young people. Dr. Ewing earned a Ph.D. from Harvard University and is recognized as a leader and social influencer, especially in conversations involving academia, writing, black women, and the intersection of politics and popular culture. Sponsored by The Commons.

University in the Art Museum for Graduate Students
Thursday, February 1 | 3 p.m.-4:30 p.m.
Spencer Museum of Art, 1301 Mississippi St.
University in the Art Museum introduces graduate students to opportunities for object-based teaching, learning, and research through collaborative partnerships with the Spencer Museum of Art. This workshop includes discussions led by graduate students in the departments of Women, Gender, and Sexuality Studies; Geography; and Atmospheric Science. Advance registration is required by Monday, January 29. Register online at https://spencerart.ku.edu/uam.

Extraordinary Animals: Awesome Adaptations
Sunday, February 4 | 1 p.m.-3 p.m.
KU Natural History Museum, 1345 Jayhawk Blvd.
At this new monthly animal event, parents and children are invited to learn about animals of Kansas. Museum Animal Specialist Ashley Welton will offer presentations about animal adaptations using touchable specimens from the museums collections at 1:15, 1:45 and 2:15 pm. 

FeBREWary at the Watkins
Thursday, February 15 | 6 p.m.-9 p.m.
Watkins Museum of History, 1047 Massachusetts St.
The Watkins, in partnership with Lawrence Beer Co., presents an evening of beer, food, and knowledge! Enjoy beer and a fascinating talk on brewing provided by Lawrence Beer Co., plus food from local restaurants and an informal museum tour. Tickets are $15 for DCHS members, $20 for non-members. You may sign up online or contact the museum at 785-841-4109. We recommend buying in advance. Ages 21 and over only, please. More information and registration.

Winter Table: An Evening of Herpetology
Wednesday, February 28 | 6:30 p.m.
KU Natural History Museum, 1345 Jayhawk Blvd.
A celebration of more than 100 years of KU herpetology research programs and the careers of Linda Trueb and Bill Duellman. Explore the Natural History Museum's reptile and amphibian collections and enjoy appetizers and drinks. Dine in the Panorama Gallery with KU herpetology scientists and students conducting reptile and amphibian research across the globe. 

6:30 pm: appetizers, drinks and science salon
7:00 pm: dinner and program
$50 per person 

Reserve your space now at the 2018 Winter Table by ordering tickets online. Tickets are $50 per person. You may also call 785-864-4450 to purchase by phone or you may purchase tickets at the museum lobby during business hours. Questions? Contact biodiversity@ku.edu or 785-864-4450.

Home to 50+ departments, centers, and programs, the School of the Arts, and the School of Public Affairs and Administration
KU offers courses in 40 languages
No. 1 ranking in city management and urban policy —U.S. News and World Report
One of 34 U.S. public institutions in the prestigious Association of American Universities
44 nationally ranked graduate programs.
—U.S. News & World Report
Top 50 nationwide for size of library collection.
—ALA
23rd nationwide for service to veterans —"Best for Vets," Military Times