منابع مشابه
Genetic recombination in sexual crosses of phycomyces.
Sexual crosses between strains of Phycomyces blakesleeanus , involving three auxotrophic and one color marker and yielding a high proportion of zygospore germination, are described. Samples of 20-40 germ spores from 311 individual fertile germ sporangia originating from five two-factor and three three-factor crosses were characterized. The results show: (1) absence of any contribution of apogam...
متن کاملSexual Species Are Separated by Larger Genetic Gaps than Asexual Species in Rotifers
Why organisms diversify into discrete species instead of showing a continuum of genotypic and phenotypic forms is an important yet rarely studied question in speciation biology. Does species discreteness come from adaptation to fill discrete niches or from interspecific gaps generated by reproductive isolation? We investigate the importance of reproductive isolation by comparing genetic discret...
متن کاملThe effect of sex on the mean and variance of fitness in facultatively sexual rotifers.
The evolution of sex is a classic problem in evolutionary biology. While this topic has been the focus of much theoretical work, there is a serious dearth of empirical data. A simple yet fundamental question is how sex affects the mean and variance in fitness. Despite its importance to the theory, this type of data is available for only a handful of taxa. Here, we report two experiments in whic...
متن کاملA mathematical model for the phase of sexual reproduction in monogonont rotifers.
Recently, the optimal sex allocation in monogonont rotifers is studied, and, as a closely related question, the relative frequencies of the relevant types of mictic females. The authors focus on the evolution of the age at which young mictic females lose their fertilization susceptibility and they address the threshold age of fertilization that maximizes resting egg production. Assuming that a ...
متن کاملHopf bifurcation in a structured population model for the sexual phase of monogonont rotifers.
We are studying a population of monogonont rotifers in the context of non-linear age-dependent models. In the sexual phase of their reproductive cycle we consider the population structured by age, and composed of three subclasses: virgin mictic females, mated mictic females, and haploid males. The model system has a unique stationary population density which is stable as long as a parameter, re...
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ژورنال
عنوان ژورنال: Heredity
سال: 1977
ISSN: 0018-067X,1365-2540
DOI: 10.1038/hdy.1977.76