Biomedical subjects

A E Bell

Publications and source records attributed to A E Bell.

38 records · Page 3Linked to original sources

PubMedDate not supplied

Comparison of crossbred and purebred selection for a heterotic trait in highly selected populations of Tribolium.

Selection on the basis of crossbred performance (RRS) was compared for 11 generations to within-line selection based on purebred performance (WLS) for a heterotic trait, 13-day larval weight in Tribolium populations previously subjected to 30 generations of purebred selection. RRS crossbreds gained slightly less than crossbreds of WLS populations. RRS purebreds showed a much smaller composite populations were greater than those observed for the continued populations. A model for the genetic control of larval weight is suggested in which there are both dominant and overdominant loci and homozygotes are less fit than heterozygotes.

Animals↗

PubMedDate not supplied

Heritability in retrospect.

The origin of the word heritability remains unknown. Its usage has evolved through three stages, becoming more restrictive in its meaning along the way. In the initial stage, 1832 and possibly earlier, heritability was used to denote the hereditary transmission of characteristics or material things, simply having the capability (legally or biologically) of being inherited. The second stage, beginning around the turn of this century, followed Johannsen's classical definition of nongenetic or environmental fluctuations distinct from genotypic differences, and usage closely approximated "broad sense heritability" and Johannsen's Erblichkeit. Finally, in 1936, we come to the modern day usage of narrow sense heritability, the ratio of additive genetic variance to the total phenotypic variance within a population, and credit Dr. J.L. Lush with its origin.

Animals↗