David Shenk mentions in Chapter 8 the significance of a 'hidden' environment on the development of a child - and how the hidden environment has as much of an impact on the child as the visible and measurable environment and genes do. Because, "each human child is his/her own unique genetic identity conceived in his/her own distinctive environment," Shenk argues that the strict determinate nature of Mendelian genetics can't be considered legitimate (130). However, one cannot assume that through solely observing the environment of spectacularly successful individuals, scientists can create the 'ideal' environment for successful offspring.
How does this concept of a hidden environment acting as a factor connect to evolution? Do you think that we, as humans, may eventually be able to find the 'ideal' environment for successful offspring even with the hidden environment in play? Why?
(Adithi Rao, adithi.a.rao@gmail.com)
How does this concept of a hidden environment acting as a factor connect to evolution? Do you think that we, as humans, may eventually be able to find the 'ideal' environment for successful offspring even with the hidden environment in play? Why?
(Adithi Rao, adithi.a.rao@gmail.com)
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ReplyDeleteShenk emphasizes the GxE equation throughout this book, and it is clear that the environment plays a crucial role in developing one’s traits, including the “hidden” environment. When Shenk describes Mendelian genetics, he explains the basics and goes into how real genetics is much too complicated to be effectively shared with the general public. Basically, Shenk claims that “we do not inherit traits…instead, we develop traits (Shenk 21). We now know the complexity of genetics through the studies of interactionists, or those who emphasize “on the dynamic interaction between genes and the environment” (Shenk 18). The process that takes place for a trait to be expressed is that “gene-environment interaction drives a unique developmental path for every unique individual” (Shenk 19). Therefore, the strict determinate nature of Mendelian genetics cannot be seriously considered by researchers. There are too many outside factors that alter which traits are expressed in an organism.
ReplyDeleteEven genetically identical mice that were placed in very similar environments within different cities developed quite differently. There were only a “handful of known variables existed between groups (Shenk 130), but yet there were still so many differences in the development of these mice. This experiment made it “clear that these hidden environments had affected different mouse strains in different ways” (Shenk 130). Finding the ideal environment for successful offspring would nearly be impossible considering that there are so many hidden factors present. Hypotheses, experiments, studies, and other research have proved time and time again that Darwin’s theory of natural selection is how organisms have evolved to become what they are today. Most of the research done did not control for those hidden variables because they were, well, hidden. Shown by Crabbe’s mice experiment, it is clear that the hidden environment changed the development of each mouse. Although there is a hidden environment everywhere, natural selection seems to pull through because the research to prove this theory does capture all of the major variables that would affect the results. Even with these unknown factors, the theory seems to hold true. This may be because the unknown factors are not significant enough to determine an organism’s ability to survive and reproduce. Although traits would be altered because of the environment, the differences may not be drastic enough to sway the animal between life and death. Even though these mice began with the same genetic coding, the hidden environment could’ve altered this coding and turned certain genes on and off, that led to the differences in development of each mouse. Point mutations could happen within the DNA of these mice as their lives went along because the unknown factors may have influenced them to do so. There are different types of point mutations, which are localized changes in the location of alleles (Campbell 344). Crabbe’s experiment helped Shenk to prove that an organism’s traits are effected by both nature and nurture (http://genealogy.about.com/cs/geneticgenealogy/a/nature_nurture.htm).
Although finding the ideal environment for raising successful offspring with hidden factors in play would be close to impossible, I believe that it can happen one day. The level of detail that would need to be taken to achieve this would be overwhelming, yet still possible. In the future, researchers might find the other tiny factors that affect development and record how each difference affects one’s traits. Combinations of factors would also need to be considered.
(Kalista Noegroho, Kalista.dara@gmail.com)
The concept of the hidden environment proves the complexity of the engagement between genes and the environment, which connects to both themes of evolution and interdependence in nature. As stated in the Course Outline book, “an organism’s phenotype is the synergistic product of genes and the environment” (COB 25). Therefore, multiple biotic and abiotic factors can affect the development of a child (http://library.thinkquest.org/CR0210243/Science%20Station/How%20living%20things%20interact%20with%20their%20environment/relationship%20of%20biotic%20and%20abiotic%20factors.htm ). Biotic factors include the people the child grows up around and food consumed like vegetables and meat. Abiotic factors could include the weather and the type of terrain. People growing up on a farm develop to be more acute to sounds, natures, and other people than to those growing up in the Bronx, adapting to a fast lifestyle of crowded streets and noise (http://recomparison.com/comparisons/100448/living-on-a-farm-vs-living-in-the-city/ ). These different factors will affect gene expression and development. The hidden environment consists of these same abiotic and biotic factors, but are just unknown specifically to scientists. By developing traits and skills through these unknown factors, the organism could be developing factors that would aid them in survival and reproduction. The human brain is said to be “primed for plasticity; [it was] built for challenge and adaptations” (131). Because of this, humans are better suited to adapt to their environment, making it easier to ‘survive and reproduce’. The ability to survive and reproduce is favored in natural selection, where a trait that is useful in an environment can be passed along when the organism survives and reproduces, passing the gene along (Campbell 457-460). But, with the concept of the “hidden environment”, it is unpredictable what type of phenotype or gene is expressed. This could actually prove beneficial in evolution. If a person grows up affected by a hidden environment to develop a trait or characteristic that allows them to be better suited to survive and reproduce, those genes will be passed on. This trait that is developed happens because “brain development is not merely a process of the unfolding of a genetic plan […but] is an activity-dependent process at the molecular, cellular, and organismal levels” (131). This ties together the ideas of interdependence in nature and evolution with Shenk’s GxE model.
ReplyDeleteAs said by Shenk, this type of complex environment is “our world”; therefore, “young ones experienced so many hidden and unpredictable influences from genes, environment, and culture that there’d be simply no telling what they would turn out like” (130). With saying this, I don’t believe that humans will be able to find the ‘ideal’ environment for successful offspring because of the factors of the hidden environment, and from the different ways people determine success. As Shenk states it, “intelligence is not fixed but waiting to be developed” (131). Therefore, different intelligence skill will need to be developed depending on the environment of the offspring. Of course, people already have begun to try to map out what is considered to be the “ideal environment” for what they believe will make kids “successful”: some believe it is giving children enough play time, while others believe it is starting their kid off at a prestigious kindergarten with long hours of sitting in classrooms and reading (http://www.livestrong.com/article/168856-the-best-learning-environment-for-children/; http://news.bbc.co.uk/2/hi/7234578.stm). But, in the end, how can one determine one environment to be better, or more ideal, than the other? A child growing up to be a fisherman will need to learn very different skills than a student growing up to be a CEO. They will both develop and learn through associative learning, like trial and error, and cognition learning, but what they acquire will be different (1126-1127). Therefore, it is impossible to classify what environment is “ideal”. The idea of the hidden environment adds even more to this complexity because it is unpredictable about how a child will turn out due to these factors. A pair of twins growing up in the same family under the same rules and parenting will most likely end up having different interests, hobbies, friends, and talents. Everybody develops different depending on how the genes interfere and interact with the environment; therefore, it would be impossible to pinpoint a perfect environment to grow up in because people will react differently, and due to hidden factors, develop differently, for the worst or for the better.
ReplyDelete(Lea Nowack, lea.nowack123@gmail.com)