"We suggest that isotretinoin creates a Propionibacterium 'population bottleneck
' that selects for 'healthy' Propionibacterium communities and other sebaceous skin taxa that persist after treatment, resulting in long-term acne remission [i.e., normal skin]," the investigators wrote.
Ecological and demographic data point to a recent population bottleneck
for the Common Nighthawk in southeastern South Dakota.
Identifying the Population Bottleneck
and Resolving the EN SO Paradox
The apparent low diversity in the Southern Africa black rhinoceros infer a population bottleneck
Significant heterozygote deficiency relative to the number of alleles indicates recent population growth, whereas heterozygote excess relative to the number of alleles indicates a recent population bottleneck
(Cornuet and Luikart, 1996).
Fragmentation and small population size are risk factors for population bottleneck
(a loss of genetic variation due to reduction in population size), genetic drift, and potential loss of population viability (Neuwald, 2010).
This population bottleneck
, along with their tendency to marry within the population may have caused some traits or alleles to be more common in a process known as genetic drift.
"There is a population bottleneck
between Africa and the rest of the world; very few people were involved in the initial migration from Africa," Brandt says.
However, about 0.7 Myr ago, the panda population began to decline due to the two largest Pleistocene glaciations happened in China, and its first population bottleneck
occurred at about 0.3 Myr ago.
An empirical genetic assessment of the severity of northern elephant seal population bottleneck
By examining inter-annual genotypic variation in Eel Pond, it is possible to determine whether this annual cycle of die-off and regrowth can result in a population bottleneck
, or shift in genetic composition.
Yellow-billed magpies may be at risk of a decline and population bottleneck
. Observations and experience with the yellow-billed magpie and WNV may provide insights for other endangered corvids that have not yet been exposed to WNV, including the Hawaiian crow (Corvus hawaiiensis) and island scrub jay (Aphelocoma insularis).