The proximate determinants of sex ratio in C. elegans populations

The proximate determinants of sex ratio in C. elegans populations.

The soil nematode Caenorhabditis elegans is an example of a species in which self-fertilizing hermaphrodites predominate, but functional males continue to persist--allowing outcrossing to persevere at low levels. Hermaphrodites can produce male progeny as a consequence of sex chromosome non-disjunction or via outcrossing with males. Consequently, the genetics of sex determination coupled with t...

Sex Ratio Compensation in Ant Populations.

The proximate determinants of insect size

One of the least understood aspects of animal development--the determination of body size--is currently the subject of intense scrutiny. A new study employs a modeling approach to expose the factors that matter in the control of insect size.

Sex ratio bias in managed populations of hylobatids.

A number of explanations have been proposed for the occurrence of sex ratio bias in primates, including the Trivers-Willard hypothesis on differential investment, local resource competition or enhancement as a result of sex-biased dispersal, dominance-related advantages conferred on one sex but not the other, and the fragile male hypothesis. However, none of these theories was thought to be app...

Sex - ratio in natural populations of Drosophila mediopunctata ( Diptera : Drosophilidae

The sex-ratio trait has been described as the production of progenies with unequal sexual proportions induced by meiotic drive. In Drosophila, meiotic drive of the X chromosome against the Y (yielding female biased progenies) is known in several species, including in Drosophila mediopunctata. This species has been previously studied, and the chromosome mechanism of the meiotic drive in sex-rati...