From the virtual change of the sum of the electromagnetic energy and the couple energy produced by the migratory variation we can get the electromagnetic force and in this case the virtual variation of the volume should be considered.
Recent studies exploring the molecular genetic basis for migratory variation in animals have identified polymorphisms in two genes (CLOCK and ADCYAP1) that are linked to circadian rhythms and correlate with migratory propensity and phenology among individuals and populations.
The lack of consistent relationships between molecular genetic variation and migratory variation suggested by our data are overall consistent with previous research on both CLOCK and ADCYAP1, as these genes are related to migratory and breeding behavior in only some of the species investigated.
Pre-treatment of cultures with mitomycin C, to block mitosis, may be used to discern migratory phenotypes from variations in proliferative capacity.
Furthermore, barn swallows (Hirundo rustica) show substantial variation in migratory phenotype, but very little variation at this CLOCK polymorphism.
Size structure and density are variables classically assessed in ecological monitoring, but to interpret data on these in species that may or may not contain migratory life-history variation, it is necessary to know about life-history distribution in the population.
Of broader significance were Berg's findings on the periodicity of reproduction among fishes and the influence of climatic variations on migratory species.
The Bledsoes, aided by a small network of ultra-conservative amateur astronomers, say evidence of the president's extra-terrestrial birthplace can be found by studying records of lunar eclipses, tidal variations, and migratory bird patterns across the northern hemisphere.
Variations in migratory and invasive proprieties induced by hHSS1 in different glioma cell lines are likely due to diverse genetic background (e.g. mutations and deletions) [ 13], probably involving other signaling pathways and molecules.
Staffan Bensch, an ornithologist at Lund University in Sweden, is not convinced that this gene, not another nearby, is what's causing the variation in migratory behavior.
