So the geneticist was referring to a limited genetic diversity due to descent from few ancestors, which is apparently the case today.
He said more mixed flocks would be a good thing in the long run when climatic or other conditions changed so that selection and evolution of the best fitted could proceed successfully.
Is the form of inbreeding described in my question a danger to the survival of humans, which the geneticist seemed to imply by stating that thanks to mixed couples ‘some would survive’.
Answer
Dear Thijs,
What your professor probably meant is that for the past thousands of years, and to a large extent still today, humans have mainly reproduced with people from their own region. As a result, the diversity within each region is quite low. This is also the reason that, for example, Europeans, Africans and Asians differ so much in appearance. There has been very little exchange of genetic material between these groups over time. Today, however, more mixing is beginning to occur (mixed marriages).
The greatest danger of low diversity within regions is that people are susceptible to the same diseases. Just think of the Native Americans during the colonization of America: the majority died of diseases such as the plague. Diseases to which most Europeans were resistant, but Indians were not. More diversity within the Native American population would have resulted in a greater percentage of people being resistant to these diseases. As a result, these diseases could not have caused so many victims.
I wouldn’t call it a real danger to human survival. But more diversity within populations has a positive effect on the survival chances of our species.
regards
Answered by
dr. ir. Tim Wings
Plant breeding, Molecular Genetics, clover, progeny, quinoa, seed cultivation
Burg. van Gansberghelaan 96 box 1 9820 Merelbeke
http://www.ilvo.vlaanderen.be
.