Small tissue samples collected from 238 wild turtles at 15 different locations across their range in Southern Mexico, Belize and Guatemala revealed a "surprising lack" of genetic structure, the scientists write in a recent paper in the journal Conservation Genetics.
A genetic study focusing on the Central American river turtle (Dermatemys mawii) recently turned up surprising results for a team of Smithsonian scientists involved in conserving this critically endangered species. Small tissue samples collected from 238 wild turtles at 15 different locations across their range in Southern Mexico, Belize and Guatemala revealed a "surprising lack" of genetic structure. Credit: Photo courtesy of Gracia González-Porter
The turtles, which are entirely aquatic, represent populations from three different river basins that are geographically isolated by significant distance and high mountain chains.
"We were expecting to find a different genetic lineage in each drainage basin," explains the paper's main author Gracia González-Porter of the Center for Conservation and Evolutionary Genetics at the Smithsonian Conservation Biology Institute. "Instead, we found the mixing of lineages. It was all over the place." Despite appearing isolated, the genetic data showed the different turtle populations had been in close contact for years.
"But how?" the researchers wondered.The best possible explanation, González-Porter and her colleagues say, is that for centuries humans have been bringing them together. The turtles have been used as food, in trade and in rituals for millennia, widely transported and customarily kept in holding ponds till they were needed.
One specimen of D. mawii was found in an ancient Teotihuacan burial site in Mexico, a spot located more than 186 miles from the known range of this turtle, the researchers say. An ancient sculpture of a Central American river turtle at the National Museum of Anthropology in Mexico City was found in the Basin of Mexico, more than 217 miles from the turtle's range.
"The Central American River turtle is tame and resilient," González-Porter explains, "which makes it easy to transport. Their shells give them lots of protection. People don't have refrigeration so they put the turtles in ponds in their back yards."
During the rainy season in the tropics, the water flows are huge, she says. Rivers and ponds flood, captive turtles escape and mix with the local turtles.
This ancient practice still persists today. In Guatemala, Central American river turtles are kept in medium-sized ponds where they can be easily captured when needed. Similarly, in the State of Tabasco, Mexico, captured turtles are kept in rustic ponds and raised until they are either consumed or sold.
The genetic analysis of the Central American River turtle was initiated because these animals are critically endangered, González-Porter says.
They are the last surviving species of the giant river turtles of the family Dermatemydidae. D. mawii is currently the most endangered turtle species in Central America. A recent increase in the commercial demand for its meat has pushed it to the brink of extinction—2.2 pounds of their meat can fetch $100. Most local populations have disappeared and this turtle is now largely restricted to remote areas that are inaccessible to humans.
The article "Patterns of genetic diversity in the critically endangered Central American river turtle: human influence since the Mayan age?" was co-authored by Gracia González-Porter and Frank Hailer of the Center for Conservation and Evolutionary Genetics at the Smithsonian Conservation Biology Institute; Jesús Maldonado of Center for Conservation and Evolutionary Genetics at the Smithsonian Conservation Biology Institute and the Department of Vertebrate Zoology at the Smithsonian's National Museum of Natural History; Oscar Flores-Villela of the Museo de Zoología Facultad de Ciencias, México; and Rony Garcia-Anleu of the Wildlife Conservation Society-Guatemala Program, Guatemala.
John Gibbons | EurekAlert!
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences