Yesterday 10:06 PM
(This post was last modified: Yesterday 10:26 PM by C C.)
So much for inbreeding depression, where an isolated species needs more than just a handful of individuals to ensure enough genetic diversity to overcome harmful, inherited traits and other obstacles. According to the Wikipedia entry about these invaders of Cincinnati, the population of today might have only been descended from a mere three of the ten individuals. Then there are those hippopotamuses in Colombia, but that's another narrative.
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Wall lizards in Ohio reproduced their way out of a genetic bottleneck
https://www.eurekalert.org/news-releases/1130211
INTRO: Non-native wall lizards living in Cincinnati, Ohio, have thrived against the odds thanks to an ability to expand their population more quickly than any inbreeding-amplified harmful genes could weaken their chances for survival, new research suggests.
An estimated 10 of these European common wall lizards arrived in southwest Ohio in the 1950s, brought home by a boy who smuggled them in his luggage after a vacation in northern Italy. Now, hundreds of thousands – and maybe even millions – of them scamper through urban parks and neighborhoods across Cincinnati. They’re called “Lazarus lizards” in a nod to the boy’s family, founders of the Lazarus retail chain.
Researchers sequenced genomes from four different populations of the lizards, looking for genetic clues to explain how this tiny army could complete such a successful invasion. And though the analysis showed evidence of some loss of genetic variation and a dip in population size, the findings led the team to propose that rapid population growth was a major key to their survival, along with the likelihood that living conditions in Ohio resembled what they were used to back home.
“They just grew so fast. If you think you have a bottleneck, but it doesn’t last very long, then you don’t have a bottleneck,” said senior study author H. Lisle Gibbs, professor emeritus of evolution, ecology and organismal biology at The Ohio State University. “The hypothesis that we argue is they just grew their way out of their potential genetic problem.
“In some ways, we’re disproving the importance of genetic factors to the system, because it doesn’t really explain a lot about the tremendous success of these lizards in Cincinnati,” he said. The study was published recently in the journal Molecular Ecology.
Genomes from four sets of samples were sequenced and analyzed for the study: a group collected in 2009 from the source location in northern Italy; samples from two Cincinnati populations collected in 2007 and 2022; and samples from a population that existed briefly in 2021 in Columbus, Ohio, which served as a surrogate for the original lizards introduced to Cincinnati in 1951 – in that it was a recent introduction likely founded by just a few individuals.
Results showed that the lizards experienced reduced genetic variation after their arrival in Cincinnati, but the loss didn’t seem to have an effect on population health.
Based on what was seen in the Columbus population – lots of inbreeding, evidence of homozygosity that would increase the risk for harmful gene variants that could lower survival, and a big drop in numbers followed by rapid growth – the researchers concluded a similar scenario played out in Cincinnati decades ago.
“But all of the inbreeding with one another didn’t seem to matter. They were able to get over that hump and grow like crazy,” Gibbs said... (MORE - no ads)
- - - - - - - - - - - - - - - -
Wall lizards in Ohio reproduced their way out of a genetic bottleneck
https://www.eurekalert.org/news-releases/1130211
INTRO: Non-native wall lizards living in Cincinnati, Ohio, have thrived against the odds thanks to an ability to expand their population more quickly than any inbreeding-amplified harmful genes could weaken their chances for survival, new research suggests.
An estimated 10 of these European common wall lizards arrived in southwest Ohio in the 1950s, brought home by a boy who smuggled them in his luggage after a vacation in northern Italy. Now, hundreds of thousands – and maybe even millions – of them scamper through urban parks and neighborhoods across Cincinnati. They’re called “Lazarus lizards” in a nod to the boy’s family, founders of the Lazarus retail chain.
Researchers sequenced genomes from four different populations of the lizards, looking for genetic clues to explain how this tiny army could complete such a successful invasion. And though the analysis showed evidence of some loss of genetic variation and a dip in population size, the findings led the team to propose that rapid population growth was a major key to their survival, along with the likelihood that living conditions in Ohio resembled what they were used to back home.
“They just grew so fast. If you think you have a bottleneck, but it doesn’t last very long, then you don’t have a bottleneck,” said senior study author H. Lisle Gibbs, professor emeritus of evolution, ecology and organismal biology at The Ohio State University. “The hypothesis that we argue is they just grew their way out of their potential genetic problem.
“In some ways, we’re disproving the importance of genetic factors to the system, because it doesn’t really explain a lot about the tremendous success of these lizards in Cincinnati,” he said. The study was published recently in the journal Molecular Ecology.
Genomes from four sets of samples were sequenced and analyzed for the study: a group collected in 2009 from the source location in northern Italy; samples from two Cincinnati populations collected in 2007 and 2022; and samples from a population that existed briefly in 2021 in Columbus, Ohio, which served as a surrogate for the original lizards introduced to Cincinnati in 1951 – in that it was a recent introduction likely founded by just a few individuals.
Results showed that the lizards experienced reduced genetic variation after their arrival in Cincinnati, but the loss didn’t seem to have an effect on population health.
Based on what was seen in the Columbus population – lots of inbreeding, evidence of homozygosity that would increase the risk for harmful gene variants that could lower survival, and a big drop in numbers followed by rapid growth – the researchers concluded a similar scenario played out in Cincinnati decades ago.
“But all of the inbreeding with one another didn’t seem to matter. They were able to get over that hump and grow like crazy,” Gibbs said... (MORE - no ads)