Interspecies hybridization is creating a new problem in the conflict with invasive pythons in Florida. A few years ago, scientists discovered that a large number of giant pythons prowling the Everglades were hybrids created by mating between two different species, the Burmese python ( Python bivittatus ) and the Indian python ( P. molurus ). In particular, the hybrid pythons seemed to adapt better to their new environment than their parents, IFL Science reported on October 21.

As their names suggest, Burmese and Indian pythons are native to tropical Asian forests, not Florida swamps. Researchers believe they were introduced to the state in the 1970s, likely through the exotic pet trade. Populations exploded in August 1992 when Hurricane Andrew destroyed a python breeding facility near the Everglades, releasing a large number of pythons into the wild.

The new swamp environment was perfect for the pythons. The giant pythons quickly established breeding populations, outcompeting native animals with their voracious appetites and hunting skills. Since the python population exploded a few decades ago, small mammals such as marsh rabbits, cottontails, and foxes have all but disappeared from the Everglades. A 2012 study found that the Everglades raccoon population had declined 99.3 percent, opossums had declined 98.9 percent, and bobcats had declined 87.5 percent since 1997.

Efforts to combat invasive pythons have made little progress, but scientists are closely monitoring python populations in search of solutions. In 2018, a team from the U.S. Geological Survey (USGS) conducted a genetic analysis of about 400 Burmese pythons captured in a large area of ​​South Florida. The study, published in the journal Ecology and Evolution, found that at least 13 of the pythons were genetically hybrids of Burmese and Indian pythons, suggesting that they were the product of interspecific hybridization.

“The pythons in South Florida are recognizable as Burmese pythons physically, but genetically it’s a more complicated story,” said Margaret Hunter, a USGS geneticist and study leader.

Typically, when two similar species mate, the offspring are at a disadvantage. They may be sterile or face challenges that make them less suited to their environment. However, sometimes the right combination can produce a hybrid that is superior to its non-hybrid counterpart, a condition called hybrid vigor.

"Interspecific hybridization can lead to hybrid vigor, which means the best traits of two species are passed on to their offspring. Hybrid vigor can lead to better adaptation to environmental stress and change. In invasive populations like the Burmese python in South Florida, this can lead to wider distribution or faster spread," Hunter explains.

Meanwhile, the fight against invasive pythons continues. Part of the reason python populations are so difficult to control is that they are extremely good at blending into their environment. Genetic engineering could give scientists new weapons to better understand the threat. “By using genetic tools and techniques and continuing to track the movement patterns of invasive pythons, we can better understand their habitat preferences and resource use,” said Kristen Hart, an ecologist at the USGS and co-author of the study.

An Khang (According to IFL Science )