From the lab of Dr. Ronald Burton:
Scientists find that interactions between different types of DNA determine hybrid fitness
“When individuals from different populations of the same species interbreed, there is often ‘hybrid vigor’ in the first generation, meaning that the offspring have improved function and fare well,” said Ron Burton, a professor of marine biology at Scripps. However, when this generation produces offspring, the second generation hybrids show a range of fitness levels – in this study defined as growth rate – with many doing quite poorly.
These findings from this study have broad implications for conservation initiatives in which people introduce or move formerly separated populations, and as populations migrate due to climate change and other environmental stressors. Although each population may be intrinsically healthy, incompatibilities between DNA types between populations may result in reduced fitness when populations interbreed.