On the Role of Inversions in Wild Populations of Drosophila pseudoobscura

Epling, Carl; Mitchell, Donald F.; Mattoni, R. H. T.

doi:10.2307/2405344

Cited by 21 publications

(26 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This situation is consistent with the stable inversion polymorphisms observed, for example, in natural populations of D. persimilis (Coyne et al 1992) and laboratory populations of D. pseudoobscura (Dobzhansky 1954;Wallace 1968;Ohta 1971). If the fitnesses of alleles involved in local adaptation vary with environmental conditions, as suggested by laboratory experiments on flies (Dobzhansky 1954), then the inversion frequencies could cycle seasonally, as is seen in D. pseudoobscura (Epling et al 1953;Dobzhansky 1971). If the alleles favored in one population (or species) are incompatible with those favored in the other, inversions will show underdominance, as seen in many interspecific crosses (White 1978;King 1993).…”

Section: Discussionsupporting

confidence: 81%

Chromosome Inversions, Local Adaptation and Speciation

2006

View full text Add to dashboard Cite

We study the evolution of inversions that capture locally adapted alleles when two populations are exchanging migrants or hybridizing. By suppressing recombination between the loci, a new inversion can spread. Neither drift nor coadaptation between the alleles (epistasis) is needed, so this local adaptation mechanism may apply to a broader range of genetic and demographic situations than alternative hypotheses that have been widely discussed. The mechanism can explain many features observed in inversion systems. It will drive an inversion to high frequency if there is no countervailing force, which could explain fixed differences observed between populations and species. An inversion can be stabilized at an intermediate frequency if it also happens to capture one or more deleterious recessive mutations, which could explain polymorphisms that are common in some species. This polymorphism can cycle in frequency with the changing selective advantage of the locally favored alleles. The mechanism can establish underdominant inversions that decrease heterokaryotype fitness by several percent if the cause of fitness loss is structural, while if the cause is genic there is no limit to the strength of underdominance that can result. The mechanism is expected to cause loci responsible for adaptive species-specific differences to map to inversions, as seen in recent QTL studies. We discuss data that support the hypothesis, review other mechanisms for inversion evolution, and suggest possible tests.

show abstract

Section: Discussionsupporting

confidence: 81%

Chromosome Inversions, Local Adaptation and Speciation

2006

View full text Add to dashboard Cite

show abstract

“…Unfortunately, male and larval frequencies were usually added together and presented as a single generation's sample. The only exception we have found in the older literature is the study of Epling et al (3), which gives male and zygotic frequencies for repeated collections at two sites on Mt. San Jacinto in California.…”

Section: Discussionmentioning

confidence: 76%

“…Natural selection was first implicated when Dobzhansky (2) showed that the frequencies of certain gene arrangements went through seasonal cycles in two of three populations on Mt. San Jacinto in California; subsequent studies showed that these cycles were repeated in years scattered over a span of 2 decades (3,4). The frequencies of gene arrangements in the third population on Mt.…”

mentioning

confidence: 99%

Evidence for selection by male mating success in natural populations of Drosophila pseudoobscura.

Anderson¹,

Levine²,

Olvera³

et al. 1979

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Gene arrangement frequencies were determined at two stages in the life history of Drosophila pseudoobscura taken from nature. Three po ulations in the central highlands of Mexico were each sampled twice during 1976.Gene arrangement frequencies were measured in adult males and in larvae that were the offspring of females collected at the same time. The adult males were in all likelihood a representative sample of those who fathered the larvae produced by the wild females. Differences in gene arrangement frequency between these two life stages should indicate the operation of natural selection. One-third of our comparisons of common gene arrangement frequencies in males and in larvae from the next generation were statistically significant, as were one-third of our comparisons of total frequency arrays in the two life stages. We consider the components of selection that could produce such frequency changes and reason that male mating success must be the major one. Gene arrangement frequencies in the Mexican populations fluctuate within wide bounds. Selection must act to retain the polymorphism in the face of this flux in gene arrangement frequencies, and we suggest that male mating success plays an important role. One of the early triumphs of ecological genetics was the demonstration that selection in nature could be intense-in fact, one or several orders of magnitude more powerful than the founders of population genetics imagined. No experimental system played a more important role in the analysis of selection than the chromosomal polymorphism for gene arrangements in Drosophila pseudoobscura. In this species a series of inversions on the third chromosome binds large blocks of genes together as units, just as though they were alleles of a single "supergene." Natural selection was first implicated when Dobzhansky (2) showed that the frequencies of certain gene arrangements went through seasonal cycles in two of three populations on Mt. San Jacinto in California; subsequent studies showed that these cycles were repeated in years scattered over a span of 2 decades (3, 4). The frequencies of gene arrangements in the third population on Mt. San Jacinto did not cycle, but between 1939 and 1946 they underwent a directional change that Dobzhansky (5) also ascribed to natural selection. Dobzhansky and Levene (6) then showed that karyotypic frequencies in eggs laid by wild females were generally in accord with Hardy-Weinberg expectations, but that frequencies in wild males were not. They concluded that the karyotypes suffered differential mortality during the transition from fertilized egg to adult fly. That selection on the D. pseudoobscura inversions occurred in nature seemed to be settled, and it was generally taken for granted that viability differences accounted for the major part of it.Some 20 years later, a series of papers by Prout (7-10) stimulated evolutionary biologists to pay greater attention to the various components to fitness. These components determine the separate bits of selection that operate at...

show abstract

“…Since, in these same populations, eggs were laid in proportions which conformed to Hardy-Weinberg ratios, it follows that differential mortality occurred sometime between the egg and adult stages. Epling, Mitchell and Mattoni (1954) showed that the relative frequencies of homozygotes and heterozygotes among adults of D. pseudoobscura collected at Pinon Flats conformed to HardyWeinberg ratios at some times of the year. But this does not prove there were no selective differences between the genotypes at such times.…”

Section: Departure From the Hardy-weinberg Ratiosmentioning

confidence: 88%

SELECTION INDROSOPHILA PSEUDOOBSCURAIN RELATION TO CROWDING

Birch

1955

Evolution

View full text Add to dashboard Cite

On the Role of Inversions in Wild Populations of Drosophila pseudoobscura

Cited by 21 publications

References 8 publications

Chromosome Inversions, Local Adaptation and Speciation

Chromosome Inversions, Local Adaptation and Speciation

Evidence for selection by male mating success in natural populations of Drosophila pseudoobscura.

SELECTION INDROSOPHILA PSEUDOOBSCURAIN RELATION TO CROWDING

Contact Info

Product

Resources

About