“GROSS SCIENCE”—THE PROS AND CONS OF INCEST (COMMENT). In his comment on genetic diversity in endangered species, Nick sent me this link to an episode of “Gross Science” from NOVA, a PBS series put together by Anna Rothschild. This episode deals with incest in different species.
Inbreeding qualifies as “gross” because of our taboo against incest. The genetic danger of inbreeding for pandas and other endangered species is that there is an increased possibility that each parent may carry the same recessive gene. If the offspring inherits both recessive genes, the recessive traits may be harmful. There is a qualification. The recessive trait may be helpful. And genes inherited from parents who come from the same environment may well be well suited to that environment.
The video concludes with species such as some fig wasps in which, as with many wasp, bee and ant species, the male inherits only one set of genes—from the mother. A male can’t have two recessive genes, and harmful genes don’t get passed on.