Tuesday, March 8, 2016

A Hispaniolan trunk anole photographed at La Palma, Dominican Republic. Photo credit: Rich Glor

 

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.”

- Brendan Lynch, KU News

Herpetology
Sunday, January 17, 2016

Thompson Reuters recently named three KU scientists as the only KU researchers ranked "Highly Cited Researchers" for 2015.

Biodiversity Institute scientists Jorge Soberon and A. Townsend Peterson, as well as incoming professor James Bever, were selected for the list, which represents some of world’s most influential scientific minds. About three thousand researchers earned the distinction by writing the greatest number of reports officially designated by Essential Science Indicators as “highly cited papers.” This ranked them among the top 1% most cited for their subject field and year of publication, earning them the mark of exceptional impact.

Soberon’s interests are in documenting and understanding large-scale spatial patterns in the biodiversity of terrestrial species, using tools such as Geographical Information Systems software, mathematical models and software specifically for niche modeling. He also studies the political and institutional aspects of biodiversity governance. 

Together with Robert Guralnick, Soberon and Peterson edit the online, open access journal Biodiversity Informatics

Peterson’s research is diverse, ranging from systematic ornithology and species-level distributional ecology to spatial epidemiology, and the ecology of zoonotic diseases in natural systems. The general focus is on the geography of biodiversity, in a context of international collaboration and education.

James Bever, professor of biology at Indiana University, will join the KU Department of Ecology and Evolutionary Biology (EEB) and the Kansas Biological Survey (KBS) in January 2016. He is considered a world leader in microbiology, especially plant-soil microbial interactions.

Biodiversity Modeling & Policy
Sunday, January 17, 2016

Thompson Reuters recently named three KU scientists as the only KU researchers ranked "Highly Cited Researchers" for 2015.

Biodiversity Institute scientists Jorge Soberon and A. Townsend Peterson, as well as incoming professor James Bever, were selected for the list, which represents some of world’s most influential scientific minds. About three thousand researchers earned the distinction by writing the greatest number of reports officially designated by Essential Science Indicators as “highly cited papers.” This ranked them among the top 1% most cited for their subject field and year of publication, earning them the mark of exceptional impact.

Soberon’s interests are in documenting and understanding large-scale spatial patterns in the biodiversity of terrestrial species, using tools such as Geographical Information Systems software, mathematical models and software specifically for niche modeling. He also studies the political and institutional aspects of biodiversity governance. 

Together with Robert Guralnick, Soberon and Peterson edit the online, open access journal Biodiversity Informatics

Peterson’s research is diverse, ranging from systematic ornithology and species-level distributional ecology to spatial epidemiology, and the ecology of zoonotic diseases in natural systems. The general focus is on the geography of biodiversity, in a context of international collaboration and education.

James Bever, professor of biology at Indiana University, will join the KU Department of Ecology and Evolutionary Biology (EEB) and the Kansas Biological Survey (KBS) in January 2016. He is considered a world leader in microbiology, especially plant-soil microbial interactions.

Biodiversity Modeling & Policy
Sunday, January 17, 2016

Thompson Reuters recently named three KU scientists as the only KU researchers ranked "Highly Cited Researchers" for 2015.

Biodiversity Institute scientists Jorge Soberon and A. Townsend Peterson, as well as incoming professor James Bever, were selected for the list, which represents some of world’s most influential scientific minds. About three thousand researchers earned the distinction by writing the greatest number of reports officially designated by Essential Science Indicators as “highly cited papers.” This ranked them among the top 1% most cited for their subject field and year of publication, earning them the mark of exceptional impact.

Soberon’s interests are in documenting and understanding large-scale spatial patterns in the biodiversity of terrestrial species, using tools such as Geographical Information Systems software, mathematical models and software specifically for niche modeling. He also studies the political and institutional aspects of biodiversity governance. 

Together with Robert Guralnick, Soberon and Peterson edit the online, open access journal Biodiversity Informatics

Peterson’s research is diverse, ranging from systematic ornithology and species-level distributional ecology to spatial epidemiology, and the ecology of zoonotic diseases in natural systems. The general focus is on the geography of biodiversity, in a context of international collaboration and education.

James Bever, professor of biology at Indiana University, will join the KU Department of Ecology and Evolutionary Biology (EEB) and the Kansas Biological Survey (KBS) in January 2016. He is considered a world leader in microbiology, especially plant-soil microbial interactions.

Biodiversity Modeling & Policy
Friday, January 22, 2016

The University of Kansas Natural History Museum has been named the top natural history museum among public universities by Best College Reviews. In "The 30 Most Amazing Higher Ed Natural History Museums," the museum ranked fourth overall behind private university museums at Harvard, Drexel and Yale.

To be named to the select list of 30 museums, each institution had to be open to the public. Additional ranking criteria included:

• Number of artifacts/specimens in the collection
• Opportunities at the museum for college students
• Community involvement

"We are honored to receive this recognition of nationwide leadership in the study of the life of the planet for science and society,” said Leonard Krishtalka, director of the KU Biodiversity Institute and Natural History Museum. “We have the finest scientists, graduate students and public program staff in the country."

The KU Natural History Museum, a part of the Biodiversity Institute, seeks to engage and inspire diverse audiences through nature and science. The museum offers programs for the public, K-12 teachers and students and the university community, and includes four floors of exhibits. It is home to more than 9 million plant, animal and fossil specimens, and 1.5 million archaeological artifacts.

Natural History Museum
Friday, January 22, 2016

The University of Kansas Natural History Museum has been named the top natural history museum among public universities by Best College Reviews. In "The 30 Most Amazing Higher Ed Natural History Museums," the museum ranked fourth overall behind private university museums at Harvard, Drexel and Yale.

To be named to the select list of 30 museums, each institution had to be open to the public. Additional ranking criteria included:

• Number of artifacts/specimens in the collection
• Opportunities at the museum for college students
• Community involvement

"We are honored to receive this recognition of nationwide leadership in the study of the life of the planet for science and society,” said Leonard Krishtalka, director of the KU Biodiversity Institute and Natural History Museum. “We have the finest scientists, graduate students and public program staff in the country."

The KU Natural History Museum, a part of the Biodiversity Institute, seeks to engage and inspire diverse audiences through nature and science. The museum offers programs for the public, K-12 teachers and students and the university community, and includes four floors of exhibits. It is home to more than 9 million plant, animal and fossil specimens, and 1.5 million archaeological artifacts.

Natural History Museum
Friday, January 22, 2016

The University of Kansas Natural History Museum has been named the top natural history museum among public universities by Best College Reviews. In "The 30 Most Amazing Higher Ed Natural History Museums," the museum ranked fourth overall behind private university museums at Harvard, Drexel and Yale.

To be named to the select list of 30 museums, each institution had to be open to the public. Additional ranking criteria included:

• Number of artifacts/specimens in the collection
• Opportunities at the museum for college students
• Community involvement

"We are honored to receive this recognition of nationwide leadership in the study of the life of the planet for science and society,” said Leonard Krishtalka, director of the KU Biodiversity Institute and Natural History Museum. “We have the finest scientists, graduate students and public program staff in the country."

The KU Natural History Museum, a part of the Biodiversity Institute, seeks to engage and inspire diverse audiences through nature and science. The museum offers programs for the public, K-12 teachers and students and the university community, and includes four floors of exhibits. It is home to more than 9 million plant, animal and fossil specimens, and 1.5 million archaeological artifacts.

Natural History Museum
Friday, December 18, 2015
Ron Seidel

Many people are familiar with the Galapagos finches, and the evolutionary theory that differences in beak size led to the groups’ diversification. It’s one of the most popularly cited examples of a process known as adaptive radiation. Now, the frequency of that evolutionary process in nature is being challenged by a group of KU Biodiversity Institute graduate research students.

In a paper to be published in the journal Trends in Ecology and Evolution in January, the students argue why many instances of evolution previously believed to be caused by adaptive radiations are not truly “adaptive” but rather other types of evolutionary radiation altogether, or a blend of several forms.

“We read a lot of papers where something interesting biologically was going on, but it was being mischaracterized as adaptive, when truly there were other processes that were being ignored,” said graduate student Kaylee Herzog, one of the seven students who coauthored the paper.

Evolutionary radiation consists of several ways in which speciation, or the creation of new species from a single common ancestor, occurs. In early studies of evolutionary radiation, adaptive radiation was once thought to be the only way speciation could take place. This theory was proven false, after it became clear that many causes of radiation exist, oftentimes many in the same instance.

The group believes that geographic radiation in the finches could be the actual cause for changes in certain cases, or that both adaptive and geographic radiation play a role in some speciation. Geographic radiation is caused by two groups of the same species being physically separated and exposed to different environments. The high diversity of Galapagos finches is only one of several examples that the students say could be falsely attributed to adaptive radiation.

Graduate student Marianna Simoes says the paper’s concept was first initiated two years ago, when the graduate students began meeting for a macroevolutionary biology course at the University of Kansas. During the course, the students discussed types of radiation such as adaptive, exaptive, geographic, and climatic. While studying these processes, the group decided to make the occurrence of adaptive radiation the focus of their discussion group which followed the course the next semester.

In the discussion group, the students began to dig deeper into inconsistencies they found in the labeling of the processes of evolutionary radiation. The students found instances of possible false attributions to adaptive radiation in each of their specific fields of research, and brought these studies back to the group for discussion. They then teased out what they believe to be the true causes of speciation in these groups. While writing the paper, the students also named the process of pseudoradiation. This is the first time the process, which is related to but distinct from evolutionary radiation, have been summarized in one paper.

“We’ve found that adaptive radiation is not really the trigger for all of these speciations, so that’s where the rest of the different kinds of radiation come in,” graduate student Laura Breitkreuz said.

While the students maintain that adaptive radiation plays a big role in evolutionary radiation, they hope the paper will help point out the importance of recognizing other triggers that often occur.

Invertebrate Paleontology
Tuesday, November 24, 2015

Back in April, University of New Mexico Ph.D. candidate (and KU alum) Grey Gustafson  was on the hunt for a particular species of whirligig beetle in Alabama’s Conecuh National Forest, but something else caught his eye. As it turns out, this beetle is the first unequivocally new species of the whirligig family (Gyrinidae) to be described in the United States since 1991. Gustafson named it Dineutus shorti after University of Kansas coleopterist Dr. Andrew E. Z. Short.

Read more about Gustafson's discovery:

http://entomologytoday.org/2015/11/05/new-whirligig-beetle-showcases-u-s...

Entomology
Monday, November 23, 2015

LAWRENCE — During upheaval in Libya in 2013, a window of opportunity opened for scientists from the University of Kansas to perform research at the Zallah Oasis, a promising site for unearthing fossils from the Oligocene period, roughly 30 million years ago.

From that work, the KU-led team last week published a description of a previously unknown anthropoid primate — a forerunner of today’s monkeys, apes and humans — in the Journal of Human Evolution. They’ve dubbed their new find Apidium zuetina.

Significantly, it’s the first example of Apidium to be found outside of Egypt.

“Apidium is interesting because it was the first early anthropoid primate ever to be found and described, in 1908,” said K. Christopher Beard, Distinguished Foundation Professor of Ecology and Evolutionary Biology and senior curator with KU’s Biodiversity Institute, who headed the research. “The oldest known Apidium fossils are about 31 million years old, while the youngest are 29 million. Before our discovery in Libya, only three species of Apidium were ever recovered in Egypt. People had come up with the idea that these primates had evolved locally in Egypt.”

Beard said evidence that Apidium had dispersed across North Africa was the key facet of the find. He believes shifting climatic and environmental conditions shaped the distribution of species of Apidium, which affected their evolution.

“We’ve found evidence that climate change — not warming, but cooling and drying — across the Eocene-Oligocene boundary probably is the root cause in kicking anthropoid evolution into overdrive,” he said. “All of these anthropoids, which were our distant relatives, were living up in the trees — none of them were coming down. When the world became cooler and dryer in this period, what was previously a continuous belt of forest became more fragmented. This created barriers to gene flow and movement of animals from one part of forest to what used to be adjacent forest.”

With a forest broken up, there was an inhibition of gene flow that through time resulted in speciation, or the creation of new species, according to the KU researcher.

“Animals that are sequestered become different species over millions of years,” Beard said. “As the climate oscillates again, you’ve got different species of Apidium. As forests expand and contract, now you’ve got competition between species of Apidium that have never seen each other before. One species outcompetes the other, the other goes extinct, and we think that’s what we’re picking up with this Libyan Apidium, which is related to the youngest and largest species of Apidium known from Egypt.”

Beard said that Apidium zuetina would have been physically similar to modern-day squirrel monkeys from South America, but with smaller brains, and would have dined on fruits, nuts and seeds.

“We know that Apidium was a very active arboreal monkey, a really good leaper,” he said. “We know they actually had fused lower-leg bones just above the ankle joint. That’s really unusual for anthropoid primates, and the only reason for it to happen is because you like to jump a lot, as it stabilized the join between those bones and the ankle.”

The team identified Apidium zuetina through detailed analysis of its teeth.

“All of the fossils we have so far are just teeth, not even jaw bones — but fortunately, the teeth of these anthropoids are so distinct and diagnostic that they function like fingerprints at a crime scene,” Beard said. “Studying details of cusps and crests on teeth, we can determine evolutionary relationships. It might sound like thin evidence, but I suspect even with whole skeletons we’d still be focused on teeth to determine relationships. This is because teeth evolve rapidly in response to shifting diets, while an animal’s skull and skeleton typically evolves more slowly. Fortunately for paleontologists, teeth are well-documented in the fossil record because tooth enamel is the hardest part of a mammal body, durable and easy to fossilize.”

Yet, the researchers chose to name Apidium zuetina not after any of its physical characteristics, but after the Zuetina Oil Company that made the dangerous Libyan fieldwork possible.

“Without their logistical support, we couldn’t have done this work at all,” Beard said. “We did this just after end of the Libyan civil war that led to the overthrow of Gadhafi.”

Beard said the discovery took place during a brief lull in violence in Libya. But the trip to the Zallah Oasis was precarious nonetheless.

“We knew it was risky, but we thought we could go because of our local collaborator, Mustafa Salem, a geology professor at Tripoli University,” he said. “He’s revered as a father figure among Libyan geologists. An oil facility was close to some interesting sites, and after Mustafa contacted a former student who was working there, they provided our team with charter flights to an airstrip near the oil facility. Without that alone, we couldn’t have done our fieldwork — the roads are too dangerous with bandits and the like. They also gave us lodging, food, water and security.”

Beard said armed guards accompanied the team everywhere, manning trucks mounted with antiaircraft guns.

“They never asked for a nickel from us in return,” said the KU researcher. “There was an Islamist attack on a gas facility at the same time near the Algerian-Libyan border, and they killed 30-40 workers. So the security protected us and potentially saved our lives.”

Beard’s research collaborators were Pauline M.C. Coster of KU; Yaowalak Chaimanee and Jean-Jacques Jaeger of the Université de Poitiers in France; and Mustafa Salem of Tripoli University in Libya.

The National Science Foundation supported this work. 

Photos: Above, armed guards accompanied researchers during their dangerous Libyan fieldwork. Below: Researchers analyzed fossil teeth to identify Apidium zuetina as a species new to science. Map: (A) location of Zallah Oasis in Libya’s Sirt Basin and (B) closeup of Zallah Oasis and surrounding area.

Written by Brendan M. Lynch

Vertebrate Paleontology