The outcome of secondary contact between divergent lineages or species may be influenced by both the reproductive traits parental and fitness offspring; however, their relative contributions have rarely been evaluated, particularly in longer-lived vertebrate species. We performed pure reciprocal laboratory crosses Ctenophorus decresii (tawny dragon) C. modestus (swift to examine how ecologicall...

Parental conflicts can lead to antagonistic coevolution of the sexes and of parental genomes. Within a population, the resulting antagonistic effects should balance, but crosses between populations can reveal conflict. Parental conflict is less intense in self-pollinating plants than in outcrossers because outcrossing plants are pollinated by multiple pollen donors unrelated to the seed parent,...

The steps by which isolated populations acquire reproductive incompatibilities remain poorly understood. One potentially important process is postcopulatory sexual selection because it can generate divergence between populations in traits that influence fertilization success after copulation. Here we present a comprehensive analysis of this form of reproductive isolation by conducting reciproca...

The shared ancestry of mouse inbred strains, together with the availability of sequence and phenotype information, is a resource that can be used to map quantitative trait loci (QTL). The difficulty in using only sequence information lies in the fact that in most instances the allelic state of the QTL cannot be unambiguously determined in a given strain. To overcome this difficulty, the perform...

Chromosome rearrangements such as inversions have been recognized previously as contributing to reproductive isolation by maintaining alleles together that jointly contribute to deleterious genetic interactions and postzygotic reproductive isolation. In this study, an impact of potential incompatibilities merely residing on the same chromosome was found in crosses of populations of the copepod ...

Studies from a wide diversity of taxa have shown a negative relationship between genetic compatibility and the divergence time of hybridizing genomes. Theory predicts the main breakdown of fitness to happen after the F1 hybrid generation, when heterosis subsides and recessive allelic (Dobzhansky-Muller) incompatibilities are increasingly unmasked. We measured the fitness of F2 hybrids of Africa...

An n-dimensional cross comprises 2n + 1 unit cubes: the center cube and reflections in all its faces. It is well known that there is a tiling of R n by crosses for all n. AlBdaiwi and the first author proved that if 2n + 1 is not a prime then there are 2 ℵ 0 non-congruent regular (= face-to-face) tilings of R n by crosses, while there is a unique tiling of R n by crosses for n = 2, 3. They conj...

The objective of this study was to estimate heritability, heterosis, and genetic parameters involved in the control of forage yield and quality in kenaf populations, using analysis of generation means. Two crosses were used; Cuba 2032×Accession 75-71 and IX51×Everglade 41. Experimental material comprised of P1 and P2, their F1 and F2 and BC1P1 and BC1P2 generations. The effects of generations w...

Dictyostelium discoideum has proven an exceptionally powerful system for studying numerous aspects of cellular and developmental functions. The relatively small ( approximately 34 Mb) chromosomal genome of Dictyostelium and high efficiency of targeted gene disruption have enabled researchers to characterize many specific gene functions. However, the number of selectable markers in Dictyostelium...