Sorry, but everything we thought about genetics and the acquisition of
characters is being revolutionized. A few examples, not about bees
directly but with far reaching implications. (Xenobiotics are
substances foreign to an entire biological system, i.e. artificial
substances, which did not exist in nature before their synthesis by
humans)
Caste Determination in a Polymorphic Social Insect: Nutritional,
Social, and Genetic Factors
> We examined how dietary, social, and genetic factors affect individual size and caste in the Florida harvester ant Pogonomyrmex badius, which has three discrete female castes. The diet that a larva consumed, as indicated by ¦Ä13C, ¦Ä15N, and C:N, varied with caste. Both N content and estimated trophic position of dietary input was higher for major than for minor workers and was highest for gynes (reproductive females). The size and resources of a colony affected the size of only minor workers, not that of gynes and major workers. Approximately 19% of patrilines showed a bias in which female caste they produced. There were significant genetic effects on female size, and the average sizes of a major worker and a gyne produced by a patriline were correlated, but neither was correlated with minor worker size. Thus, genetic factors influence both caste and size within caste. We conclude that environmental, social, and genetic variation interact to create morphological and physiological variation among females in P. badius.
Epigenetic and phenotypic changes result from exposure to phytoestrogens
> The evolutionary origin of new characters in a lineage is considered to be a process different from that of maintenance of these characters through generations. Embryonic development plays an important role in the origin of viable phenotypic variation, on which natural selection may act further, thus, from an evolutionary perspective it is important to understand morphogenic processes taking place during early development. Morphological transformations throughout evolutionary history have been produced from context-dependent changes in genetic processes that occur during development. Considering the genome as responsive to environment has led to the hypothesis from us and others that development and/or epigenetics can provide sources of variation that are dependent on the environmental context. Moreover epigenetic status in adulthood is directionally dependent on the animal's nutritional status during early development. Nevertheless, few studies until recently have devoted attention to environmental compounds that could directly influence early changes implicated in the origin of new characters. Endocrine disruptors (ED) are among those compounds, since they are capable of driving or inducing the occurrence of new characters and/or phenotypes during early development. Endocrine disrupting environmental chemicals may function as estrogens, antiestrogens and antiandrogens, producing reproductive and developmental effects in a variety of organisms. Furthermore, exposure to environmental xenobiotics during early development may have consequences on adult stages.
--
refs
Caste Determination in a Polymorphic Social Insect: Nutritional,
Social, and Genetic Factors
Am Nat 2008. Vol. 172, pp. 497¨C507
Epigenetic and phenotypic changes result from a continuous pre and
post natal dietary exposure to phytoestrogens in an experimental
population of mice
BMC Physiology 2008, 8:17 Published: 15 September 2008
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