The Estimation of Relative Fitness of Drosophila Populations. II. Experimental Evaluation of Factors Affecting Fitness

STUDIES ON NATURAL POPULATIONS OFDROSOPHILAVI. COMPETITION BETWEENDROSOPHILA MELANOGASTERANDDROSOPHILA SIMULANS

“…melanogaster in the two cages, irrespective of their initial percentage. Similar results were found by Rloore (1952) and Barker (1963).…”

Chromosomal polymorphism and capacity for increase under near optimal conditions

“…In Drosophila, estimates of relative fitness of populations have been attempted by comparing the fecundity (Wallace, 1959), the size of the flies and the biomass produced per unit of food (Beardmore, Dobzhansky and Pavlovsky, 1960;Battaglia and Smith, 1961;Strickberger, 1963a;Ayala, 1965a, b) and the competitive ability against indicator species (Barker, 1963(Barker, , 1965Strickberger, i963b). A statistic called "the innate capacity for increase" (Andrewartha and Birch, 1954), which estimates the geometric rate of increase in numbers at optimal density with all other environmental factors defined, has been introduced as a most useful measure to compare the fitnesses of different populations.…”

The effects of sterol mutants of the yeast Saccharomyces cerevisiae on the outcome of competition between Drosophila melanogaster and D. simulans

“…This or the fixation of simulans might be expected from more successful development of D. simulans on pure erg-3 yeast. It was known that the amount and quality of the medium (Claringbold & Barker, 1961 ;Barker, 1963) (Van Delden, 1970). Van Delden noticed an increased competitive ability only after about 77 generations of competition.…”