What were the authors trying to test, and what predictions did they make?
The authors were studying the geographically isolated Scandinavian population of grey wolves. This population was founded by only two individuals and recovered by the arrival by addition of a single immigrant. The original population suffered from inbreeding depression. The addition of an immigrant granted new genetic variation and allowed the population to thrive.
What, exactly, did the authors do?
The authors collected tissue and blood samples from Scandinavian wolves and wolves from Finland and northwest Russia. DNA was extracted and analyzed. Twelve microsatellite markers were chosen to examine. The relationships between individuals was analyzed using Kinship.
What did the authors find (i.e, what were their data)?
The authors found that “ Scandinavian wolves are highly differentiated both from the neighbouring eastern population and from historical Scandinavian wolves.” All of the wolf populations were found to be significantly differentiated. The genetic variability was significantly lower in the Scandinavian wolf population than other populations. A sharp decline in heterozygosity was observed. The decrease in heterozygosity was measured at 30 % per generation which matches the estimate. The addition of a new immigrant to the population increased mean heterozygosity from 0.49 to 0.62.
How did the authors interpret their findings?
The sharp decline in heterozygosity was thought to be due to inbreeding, The expected loss of heterozygosity for a population of two individuals would be 25% per year. The observed value was 30%, which is relatively close. However the formula is likely not accurate in such small populations. As expected, the addition of the new immigrant and new alleles increased heterozygosity.
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