نتایج جستجو برای: fertilization self
تعداد نتایج: 558042 فیلتر نتایج به سال:
Self-fertilization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 8 Brother-sister mating. Sex-linked genes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 Brother-sister mating. Autosomal genes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....
The concept of gametic isolation has its origins in the 1937 edition of T. Dobzhansky's Genetics and the Origin of Species. Involving either positive assortative fertilization (as opposed to self-incompatibility) or negative assortative fertilization, it occurs after mating but prior to fertilization. Gametic isolation is generally subsumed under either prezygotic or postmating isolation and th...
This report presents a model for simulating various reproduction modes and types restrictions from nature with the genetic algorithms. We consider three reproduction modes, which are self-fertilizing, hermaphrodite excluding self fertilization, and with two differentiated gender types (male and female). We start with a model in which the reproduction mode evolves along with the rest of the geno...
A method for estimating the selfing rate using DNA sequence data was recently proposed by Milligan. Unfortunately, a number of errors make interpretation of his results problematic. In the present paper we first show how the usual coalescent process can be adapted to models that include selfing, and then use this result to find moment estimators as well as the likelihood surface for the selfing...
The predominance of outcrossing despite the substantial transmission advantage of self-fertilization remains a paradox. Theory suggests that selection can favor outcrossing if it enables the production of offspring that are less susceptible to pathogen attack than offspring produced via self-fertilization. Thus, if pathogen pressure is contributing to the maintenance of outcrossing in plants, t...
We develop coalescent models for autotetraploid species with tetrasomic inheritance. We show that the ancestral genetic process in a large population without recombination may be approximated using Kingman's standard coalescent, with a coalescent effective population size 4N. Numerical results suggest that this approximation is accurate for population sizes on the order of hundreds of individua...
The shift from outcrossing to self-fertilization is among the most common evolutionary transitions in flowering plants. Until recently, however, a genome-wide view of this transition has been obscured by both a dearth of appropriate data and the lack of appropriate population genomic methods to interpret such data. Here, we present a novel population genomic analysis detailing the origin of the...
The magnitude of inbreeding depression, a central parameter in the evolution of plant mating systems, can vary depending on environmental conditions. However, the underlying genetic mechanisms causing environmental fluctuations in inbreeding depression, and the consequences of this variation for the evolution of self-fertilization, have been little studied. Here, we consider temporal fluctuatio...
A new method of inducing self-fertilization, uniparental cytogamy, yields homozygous germinal and somatic genotypes in the ciliate Tetrahymena thermophila. Progeny are highly fertile and show a marked tendency for precocious sexual maturity. This method is highly effective in protocols designed to generate and express nonlethal dominant or recessive mutations.
Sex-allocation theory predicts that the evolution of increased rates of self-fertilization should be accompanied by decreased allocation to male reproduction (sperm production and broadcast). This prediction has found support in plants but has not previously been tested in animals, which, in contrast to biotically pollinated plants, are free of complications associated with incorporating the co...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید