Effective Population Size
Effective population size is the number of individuals in a population who contribute offspring to the next generation. Generally, the more inbred a population is, the lower its EPS will be as there are fewer unique individuals contributing to the next generation.
During 2013 we consulted with Tom Lewis (Population Geneticist at the AHT) and now have the Effective Population Size data for Dachshunds (except Wires, which he's not yet calculated). The effective population sizes for the Dachshunds we have so far are as follows:
· Long-haired: 32.9
· Smooth-haired: 45.2
· Mini Long-haired: 75.5
· Mini Smooth-haired: 65.8
· Mini Wire-haired: 70.3
Tom said:
“These figures are based on the mean inbreeding coefficients by year of birth from 1980-2009. We tend to see the rate of inbreeding flattening off in the latter years, and this looks like the case with the Dachshunds too. Extrapolating this trend to include data from 2010-2012 may reduce the rate further (and so increase the effect population sizes a bit).
Generally, we like to see an effective population size of 100, and judge those at <50 to be at risk of the effects of rapidly declining genetic diversity.”
These results are pretty much in line with other breed data that have been published previously where small numbers of registrations typically have low EPS values. So, for example, the Standard Longs are as low as vulnerable breeds like the Otterhounds.