Examples are embryo or egg selection, pre-implantation genetic testing, assisted reproduction programs, abortion, to mention just a few.
While nervous control of ovulation is clearly required to coordinate egg release with environmental and circadian factors (Yang et al., 2008), the underlying mechanism of egg selection is likely to be more complex and involve local interactions as well as communication between the ovaries.
He adds the egg, a selection of "mountain vegetables," which look like curly mushrooms, and salt and pepper.
Due to the high costs of parasitism, there should be strong disruptive selection on host egg phenotypes followed by selection on cuckoos due to high rejection rates of non-mimetic eggs by the parrotbills.
They also debate the ethics of egg donation, sex selection, gestational surrogacy and menopausal women being impregnated with younger women's fertilized eggs.
Determining the molecular mechanisms that underlie incubation behaviour is expected to help increase egg production by selection for or introgression of the underlying loci into breeds of hens that are adapted to local conditions and favoured by rural farmers.
Although our model was based on a single locus, the same principles apply if there are many different loci involved with egg fertilization, thus selection should eventually lead to the fixation of mutant alleles at many loci or to fixation of a mutant allele with a major effect at a single locus, in either case resulting in no egg fertilization at all.
Therefore, the apparent delayed onset of selection on egg number could be due to initial selection on melanin production and subsequent selection on egg number.
We also had our pick of fresh fruit, cheeses and cold cuts, pastries and cereals before even getting to the entrees, which were divided into Asian (congee, century eggs, pork dumplings) and "hot" (eggs Benedict, omelets, oatmeal) selections.
This study indicates that the second theory may be more applicable to Atlantic salmon, as several Sasa- DAA alleles were significantly associated with positive selection coefficients between egg and parr stage but with negative selection between egg and migrant stage, or vice versa.
