What began more than 50 years ago as a way to improve fishing bait in California has led a University of Tennessee researcher to a significant finding about how animal species interact and that raises important questions about conservation.
In the middle of the 20th century, local fishermen who relied on baby salamanders as bait introduced a new species of salamander to California water bodies. These Barred Tiger salamanders came into contact with the native California Tiger salamanders, and over time the two species began to mate.
"To give you a sense of the difference between these two species, they are about as closely related as humans and chimpanzees," said UT assistant professor Ben Fitzpatrick, a faculty member in the Department of Ecology and Evolutionary Biology.
Mating between two different species creates a hybrid offspring. According to Fitzpatrick, while such hybrids have been found to be successful in plant species, research has generally shown that animal hybrids are not able to sustain themselves -- in scientific terms, they lack "fitness."
This understanding made Fitzpatrick's findings especially surprising when he looked at the offspring of the two salamander species in California. He and colleague Bradley Shaffer of the University of California, Davis, found that the new hybrid salamanders were not only surviving, but in some cases, thriving.
"I thought I was studying hybrid dysfunction going into this study -- looking at how hybrids go wrong," said Fitzpatrick. "The level of vigor in these hybrids was completely unexpected."
Their research, funded by the National Science Foundation and the Environmental Protection Agency, will appear in the upcoming issue of the Proceedings of the National Academy of Sciences. It is among the first to show hybrid vigor among animal species, and Fitzpatrick noted that the work raises a number of questions for conservationists.
The California Tiger salamander, which is native to the area of the study, is listed as threatened under the U.S. Endangered Species Act, while the Barred Tiger salamander is not. The data in the article lead the researchers to predict that eventually all California Tiger salamanders will have some of the non-native genes. In a sense, the entire species would then have hybrid ancestry.
According to Fitzpatrick, the finding raises questions about whether this would be considered beneficial to the native species or not -- it depends on how conservationists choose to define the new hybrid.
"If they consider it an acceptable modification of the original species, then this could enhance the chances for survival of the California Tiger salamander," he said, "but others may consider the hybrids to be genetically impure and see hybridization as accelerating extinction."
It is not yet clear from the research what is causing the hybrids to thrive.
"Our prediction is that, because of their advantages, the hybrids will remain part of the gene pool," said Fitzpatrick. "What we don't know is if those advantages come from the synergistic interaction of certain genes -- that they are greater than the sum of their parts -- or if they simply get the 'best of both worlds' by a selection of useful individual traits from each species."
Because the research is in such early stages, Fitzpatrick and colleagues plan to broaden their study of these salamanders, and also explore the implications of these vigorous hybrids for other animals in their ecosystem.
They have expanded the number of genetic markers that they are analyzing in the hybrids to determine the extent of their genetic mixing. Given that the new hybrids are finding more success in their environment, the researchers also plan to study whether their success is reducing food supply or other resources from native species in the area.
Fitzpatrick notes that their discoveries place the work on the leading edge of hybridization studies.
"We're right at the front in thinking that these ideas may be much more generally applicable," he said. He pointed to two other studies in recent months that have explored the issue of hybridization in butterflies.
Jay Mayfield | EurekAlert!
Bioinvasion on the rise
15.02.2017 | Universität Konstanz
Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
17.02.2017 | Medical Engineering
17.02.2017 | Medical Engineering
17.02.2017 | Health and Medicine