Wildlife face many threats with spreading urbanization（都市化） , including habitat loss and inbreeding（近亲交配） when populations become fragmented and isolated¹. It doesn't help that there is a billion-dollar international industry dedicated² to the illegal trafficking of wild animals or wild animal parts. The Conservation Genetics Lab at the University of Arizona is working to conserve⁵ and protect wild animals around the world.

"Our work here deals with using genetics for wildlife conservation," said Ashwin Naidu, a doctoral candidate in the School of Natural Resources and the Environment.

One of the largest threats to wildlife is loss of genetic⁴ diversity through inbreeding, which can lead to lower levels of reproductive fitness or disease susceptibility and can endanger a population's survival.

As urbanization increases, more and more wildlife habitats are destroyed, leaving populations of wild species cut off from each other, marooned⁶（陷于孤立无援困境的） on isolated "islands" of natural land in a sea of human development. Small populations that become trapped in these fragmented habitats are unable to breed outside of their local gene³ pool – and the Conservation Genetics Lab steps in to help.

The researchers use genetic techniques to identify whether small populations of wild animals that have become isolated because of habitat fragmentation are inbred or in danger of becoming inbred.

"We want to know how individuals are related to each other across a landscape," said Naidu. "We have populations of species, and we want to see if there is genetic differentiation⁷, indicating a barrier between the populations, or if there is gene flow across the populations."

The researchers extract DNA⁸ from animal samples such as hair, bones or carcasses（尸体） , or blood samples and cheek swabs if the animal is captured.

"We amplify⁹ DNA to look for certain areas in the genome," said Naidu. "Every species has a unique DNA sequence known as a DNA barcode and every individual has a unique genetic fingerprint¹⁰."

There are several specific locations on a genome where the order of genes¹¹ or base-pair sequences varies between individuals, populations or species, said Naidu. "One is the nuclear DNA, DNA contained inside the cell's nucleus¹². Another is mitochondrial（线粒体） DNA, or DNA located inside the mitochondria of the cell."

"Once we amplify and generate multiple copies of these locations, all of this data is analyzed¹³ through DNA sequence analysis software," said Naidu. "If we want to look at variation within individuals we look at unique genome types, what we call DNA fingerprints¹⁴. If we want to look at variation within species we look at the mitochondrial DNA sequences called barcodes."

DNA fingerprints and barcodes from individual samples then are compared with a genetic database of species and populations that previously¹⁵ have been studied.

If a population is found to have inbred, the Conservation Genetics Lab goes to the rescue.

"We take a few individuals from populations that show good genetic diversity and we introduce them, or trans-locate them, into the population that is suffering from inbreeding," said Naidu. "When we introduce new genetic variation into a small population that is undergoing inbreeding, we have the potential to bring them back to a higher genetic diversity."

"We observe and monitor these populations to see if they're doing well. Then we genetically¹⁶ test them again to find out the level of genetic diversity after the translocation. Has it balanced, is it good enough for their survival? If it's not, then we need more translocations."

The same technique is applied¹⁷ to endangered or critically endangered animals that require captive breeding. Animals that are bred in captivity¹⁸ for good genetic diversity can be reintroduced to the wild to genetically rescue the wild population.

Genetics also can be used to identify species in areas where they previously haven't been known to exist. "Sometimes we find samples of an animal, such as feces, carcasses, bones or hair, and this is evidence for presence of the animal. But how do you confirm what species of animal it is? Genetics is a very useful tool for identifying the species," said Naidu. "DNA evidence can be obtained from ancient sources as well, such as fossils or bones which are being excavated¹⁹."