A threat is seen in pumas’ isolation
The isolating effects of human development are causing a sharp decline in genetic diversity among mountain lions in Southern California, a new study says.
Researchers from the University of California, Davis, collected DNA samples from more than 350 mountain lions throughout California and found that animals separated by little more than a highway have far less genetic material in common than they did just 80 years ago, suggesting that there is far less interbreeding among populations.
Pumas in the Santa Ana Mountains — effectively fenced in by Interstate 15 to the east, the Pacific Ocean to the west and Los Angeles to the north — displayed lower genetic diversity than those from nearly any other region in the state.
So severe is their isolation that the Santa Ana pumas have more in common genetically with lions 400 miles to the north than their neighbors in the Santa Monica Mountains.
Tests revealed that the decline in diversity had taken place “within four to six mountain lion generations,” said Holly Ernest, lead author of the study in PLOS One.
“So we know that this is happening on a recent time scale” and is a likely result of human development rather than natural separation from other mountain lions.
“Genetically diverse populations are better able to handle whatever nature or humans throw at them, like climate change or disease,” said Ernest, a geneticist now at the University of Wyoming.
If mountain lions lose that genetic diversity, they lose that resilience.
Other solar systems don’t play by our rule
In our solar system, smaller planets like Mercury and Venus orbit the sun closely while larger ones like Jupiter tend to be farther away. But other solar systems don’t play by our rules.
Large planets that orbit their stars very closely — some at one-tenth the distance between Earth and the sun — are known as hot or warm Jupiters (so named because they have a mass similar to our Jupiter).
And unlike the planets in our solar system, some of these planets have unusually elliptical orbits.
Researchers at the University of California, Berkeley, set out to discover how warm Jupiters came to orbit their stars so closely and whether the answer had something to do with their elliptical orbits.
The researchers ran more than 1,000 simulations to observe the movements of warm Jupiters relative to the other planets in their solar systems.
They found that large planets orbiting farther away were able to drive the large inner planets toward their stars: The planets’ surprisingly sharp orbital angles — about 35 to 65 degrees relative to one another — allow them to exert gravitational force on their companions.
“We sort of naively expected all planets to be like our solar system in that they are all orbiting in the same plane as each other,” said Rebekah Dawson, lead author of the study, which was published in the journal Science.
The isolating effects of human development are causing a sharp decline in genetic diversity among mountain lions in Southern California, a new study says.
Researchers from the University of California, Davis, collected DNA samples from more than 350 mountain lions throughout California and found that animals separated by little more than a highway have far less genetic material in common than they did just 80 years ago, suggesting that there is far less interbreeding among populations.
Pumas in the Santa Ana Mountains — effectively fenced in by Interstate 15 to the east, the Pacific Ocean to the west and Los Angeles to the north — displayed lower genetic diversity than those from nearly any other region in the state.
So severe is their isolation that the Santa Ana pumas have more in common genetically with lions 400 miles to the north than their neighbors in the Santa Monica Mountains.
Tests revealed that the decline in diversity had taken place “within four to six mountain lion generations,” said Holly Ernest, lead author of the study in PLOS One.
“So we know that this is happening on a recent time scale” and is a likely result of human development rather than natural separation from other mountain lions.
“Genetically diverse populations are better able to handle whatever nature or humans throw at them, like climate change or disease,” said Ernest, a geneticist now at the University of Wyoming.
If mountain lions lose that genetic diversity, they lose that resilience.
Other solar systems don’t play by our rule
In our solar system, smaller planets like Mercury and Venus orbit the sun closely while larger ones like Jupiter tend to be farther away. But other solar systems don’t play by our rules.
Large planets that orbit their stars very closely — some at one-tenth the distance between Earth and the sun — are known as hot or warm Jupiters (so named because they have a mass similar to our Jupiter).
And unlike the planets in our solar system, some of these planets have unusually elliptical orbits.
Researchers at the University of California, Berkeley, set out to discover how warm Jupiters came to orbit their stars so closely and whether the answer had something to do with their elliptical orbits.
The researchers ran more than 1,000 simulations to observe the movements of warm Jupiters relative to the other planets in their solar systems.
They found that large planets orbiting farther away were able to drive the large inner planets toward their stars: The planets’ surprisingly sharp orbital angles — about 35 to 65 degrees relative to one another — allow them to exert gravitational force on their companions.
“We sort of naively expected all planets to be like our solar system in that they are all orbiting in the same plane as each other,” said Rebekah Dawson, lead author of the study, which was published in the journal Science.
The Punch
No comments:
Post a Comment