On pages 160-162 Moalem looks at how the environment a mother is exposed to might effect its offspring because of the epigenome. This relates to big idea 4 (Biological systems interact, and these systems and their interactions possess complex properties) because the way the enviornment interacts with an organism could change that organisms offspring.
Epigenetics is a relatively new field of study and more about it is being discovered every day. Research and explain a species that is not explained in the book where the mother's exposure to stimulus effect her offspring. Explain how much of the species phenotypes might be determined by epigenetics and how much can never be changed. Could epigenetics effect every aspect of an organism?
( Tom Shaw tshaw4@gmail.com)
Epigenetics, the ability of an organism's genes to promote certain phenotypes based on environmental factors, is found in many species. Particularly maternal epigenetics is an excellent selective advantage. For example, the climate a mother is exposed to can alter the phenotype of her offspring, so their traits will better equip them to survive when they are born or hatched. According to the article "Mother Knows Best: Epigenetic Inheritance, Maternal Effects, and the Evolution of Human Intelligence" from the Developmental Review "temperature determines the camouflaging pattern on the wings of some butterflies. For example, the butterfly Bicyclus anynana develops wings with many eyespots in the warm, wet season, which helps it blend into the lush summer environment. Animals from this same species develop wings with fewer or no spots in the cooler, dry season, which helps them blend into the mostly brown leaf litter."(Bjorkland 218)
ReplyDeleteThe female butterflies would carry their eggs in certain environments, and depending on the average temperatures of where they laid them, their offspring's wing patterns would be different. This relates Big Ideas 1 and 4. Big Idea 4 deals with the interaction of organisms on all levels of complexity with their environments and other organisms. The determination of the butterfly offsprings' wing patter phenotype is a direct response to temperature stimuli of the mother's environment, so that they might have a better chance of avoiding predators. Also, Big Idea 1 because not only are there variations within the genes of these butterflies, but their genes for each trait are polymorphic, so each phenotype that is expressed might be a direct response to their environment. This complex survival mechanism is able to add a more immediate means for survival that is almost tailored to each organism's situation.
I don't believe that every aspect of an organism is affected by epigenetics though. In every species, there is a basic anatomy that must be followed in every individual belonging to that group. Just as Darwin disproved, a giraffe cannot be born with a 10 foot neck just because it's mother had consumed leaves from trees that were 15 feet tall. There are many different environmental factors that can affect an organism's survival, but they cannot all be accounted for by epigenetics. Moalem stated that scientists have "long noted the ability of some organisms to produce offspring that seem to be custom-tailored on the basis of the mother's experiences during pregnancy." It is amazing that species like the Bicyclus anynana are able to express phenotypes that can help them survive immediately after birth no matter what the environment is like.
(Vivian To vito4@students.d125.org)