Final answer:
Epigenetic inheritance is the transmission of changes in gene expression, induced by environmental factors, that can be passed down through generations without altering the DNA sequence.
Step-by-step explanation:
The phenomenon being discussed is known as epigenetic inheritance, which entails heritable changes in gene expression that do not involve alterations to the underlying DNA sequence. A classic example of this involves the impact of environmental factors such as toxins on pregnant rats and the subsequent effects on their offspring and even the next generation. These findings underscore the notion that both genetic and environmental factors contribute to phenotypic variation within a population, and environmental conditions can profoundly affect the expression of genes without changing the genetic code itself.
For instance, in studies conducted on rats, when pregnant females were exposed to a toxin, not only did their immediate offspring suffer from related illnesses, but the effects also persisted into the next generation. This suggests that the environment can induce epigenetic changes that are passed down through the germ line. This is vital to understanding how individuals and populations can adapt to different environmental conditions and how such changes may be passed onto subsequent generations, impacting population genetics and evolution.