The Probert Encyclopaedia of General Information

HEREDITY

Heredity is the transmission from parent to offspring of physical and intellectual characters. This has been at all times believed in, but it was only in Victorian times that the conviction was, for the first time, in the hands of Darwin, Herbert Spencer, and Wallace, been methodized so as to embody an important zoological doctrine. The Victorian view of evolution in biology rested upon the belief that acquired peculiarities, or differences which may arise between parent and offspring, could be transmitted with some probability of permanence, especially if the variation presented by the young was determined by external conditions, or if it was such as to adapt the possessor more thoroughly to the conditions under which it is placed. On the other hand, while variations may be thus permanently transmitted by heredity, yet this very tendency of the young to repeat the characters of the parent is also a check on variability, or the tendency of structure and attributes to change with the environment. It may be noted that while the strong tendency to hereditary transmission works in the majority of cases so as to perpetuate those most fitted to survive, it secures the same result in other cases by a converse action. The descent of disease in families tends ultimately to purify the race by accumulating incapacities which end in the extinction of the enfeebled strain. The discovery of genetics in the 20th century built upon the earlier theories of heredity, and explained, to a degree, the transport of the passing on of the characteristics.
Research Heredity