According to new research published in the journal Nature, genetic diversity is decreasing in two-thirds of animal and plant populations, making it more difficult for these species to adapt to changes in their environment.

A species’ population gets smaller and more dispersed long before it becomes extinct, which reduces the number of possible mates and, consequently, genetic mixing. A species becomes more susceptible to upcoming dangers like illness as a result.

“A surprisingly trend was that we saw genetic diversity declining even among” many species that aren’t considered at risk, said co-author Catherine Grueber, a conservation biologist at the University of Sydney.

The study authors analyzed data for 628 species researched between 1985 and 2019, and found that mammals and birds showed the biggest declines in genetic diversity.

“When a species has different genetic solutions, it’s better able to deal with changes,” said David Nogués-Bravo at the University of Copenhagen, who was not involved in the study.

Because of their genes, some people will fare better than others if a new disease spreads through a population or if summer rainfall changes due to climate change. A species’ chances of surviving are also increased by higher genetic diversity.

Genetic diversity can be preserved or even restored through conservation efforts that link disparate populations, essentially increasing the dating pool for a given species.

Due to freeways and urban sprawl, Florida panthers, an endangered species, have been steadily losing their habitat. Kinked tails and low male sperm counts were obvious indicators of inbreeding among the surviving big cats in southern Florida by the mid-1990s.

Eight female panthers were transported from Texas to Florida by biologists. Twenty years later, there are a lot more Florida panthers in the wild, and their genetic diversity has grown.

“Isolated populations suffer,” said Duke University ecologist Stuart Pimm, who was not part of the research. “The solution is to reconnect them.”

Header photo by Eric Prouzet on Unsplash.