David
Shenk writes that “Genes do not, on their own, make us smart, dumb, sassy,
polite…Those characteristics come from a complex interplay within a dynamic
system. Every day in every way you are
helping to shape which genes become active.
Your life is interacting with her genes.” (32) Given the complex “G x E” interplay between
the genes and the environment, could the common misconception of “inheritance”
being the primary reason for the emergence of specific traits exist because of the
effect one’s parents have on one’s children in terms of learning and early development? In other words, could the perceived “inherited”
traits really come from mimicry of and influence by someone’s parents? Also, given that strong parental influence on
offspring, could evolution be, at least in part, a result of a particular sect
of individuals being separated from others somehow, and later generations
developing with traits integral to that community? Relate your responses to the theme of continuity and change.
-Ari Bakke
Aribakke@gmail.com
Part 1:
ReplyDeleteThe apparent inheritance of traits from parents certainly stems from the influence of the parents throughout childhood. Much of this effect comes from imprinting. During a specific time in early childhood, called the critical period, young individuals imprint on their parents and learn to imitate what the parent does (Campbell 1126). In the same way, human children must imprint upon their parents to some extent, learning to reproduce the actions of their parent. As some of these actions are much more complicated than those found in nature, such as playing the piano, actually imitating the parents takes a long time to learn. Therefore, when these skills reach full development later in life people point to genetics, although imprinting early in life is the source of that skill.
David Shenk states that parents "know that genes are playing a key role and that their expression is being determined every moment by the quality of life our child leads (Shenk 132). Therefore, although genes play an important role in shaping the life of a child, genes don't determine a child's future. Rather, the way that the parents raise the child impacts gene expression in the child, thus changing the child's traits. For example, by providing their children with appropriate nutrition including protein, carbohydrates, vitamins, etc., the parents can ensure that their children's diets stimulate gene expression that in turn stimulates maximum growth (Shenk 26-27). Furthermore, parents are able to teach their children new skills. Children can learn problem solving skills simply by watching their parents (Campbell 1128). Therefore, the types of activities parents choose to engage in within the view of their children largely determine the skills that their children will develop during growth.
However, contrasting this argument is the study of Robert M. Kirkpatrick and other researchers who published their work in the journal Learning & Individual Differences, which found that heritability has a much larger impact on children's reading skills than does the environment. However, this study has one major flaw. The study evaluated the reading skills of children living with their biological parents and those who were adopted by those parents, claiming that by living with the same parents different environments were eliminated. However, this study failed to address the fact that the adoptees experienced very different environments in their early youth, when the most changes in gene expression were being made due to imprinting. Therefore, these results may actually enhance the GxE theory. As the early environment of the adoptees most likely did not do a good job of stimulating intellectual development, of course the adoptees were behind the other children in reading skills, because their early environment, even if just for a year, left them at such a disadvantage that even with the same resources afterwards the adoptees were unable to catch up in reading skills.
Part 2 is in next comment.
Aaron Zalewski (bitquest@yahoo.com)
Part 2:
ReplyDeleteThis parental influence could also explain evolution in part because as populations change separately, their parental cultures also develop separately. Therefore, with different parental cultures, the individuals born would grow up to be different from one another, and then the further distancing of parental cultures would compound upon the birth of the next generation. Living in different parental cultures, the individuals in each separate population would develop different traits due to growing up in different environments. For example, reproduction must occur differently in terms of size, rate, and so on due to environmental factors (Campbell 1180). As parents of separate populations reproduce differently to fit their environmental demands, the children learn those behaviors, and so the two populations evolve separately as the parents of each population change their behavior for reproduction and other activities from generation to generation.
This relates to the theme of continuity and change because while many traits remain continuous from parent to child due to parental influence on the child, other traits eventually change because the child cannot have the exact same environment as the parent did. The theme of continuity and change states although in some ways life remain continuous, such as through heredity, in other ways life changes over time, whether through evolution or through immediate environmental demands. Parental influence and imprinting allow for continuity by teaching the child the same skills that the parents have. However, these traits also change and evolve over time as each subsequent generation slightly changes the behaviors of the parents. Thus, the importance of parental influence allows for both continuity between generations and evolution and change over time.
Aaron Zalewski (bitquest@yahoo.com)
Part 1:
ReplyDeleteWhile the genes versus environment theory that Shenk brings up on page 32 definitely has the complexity and capability to shuffle our traits, to further that theory, he addresses the dynamic system the GxE is involved in. He says, “[Our] characteristics come from a complex interplay within a dynamic system…[and] your life is interacting with your genes” (32). The emphasis given on the flexibility of our characteristics is key to understanding the vast majority of misconceptions with “inheritance”. Because most people believe that traits can just be inherited, the jukebox analogy on page 32 and 33 is the concept of human biology is not absolute. Just like the jukebox has many songs it can play, humans can develop in the same way, however, because of that primary misconception of inheritance, a child’s learning and development has the ability to be polar opposite of what it could have been sans misinterpretation.
Shenk stresses the fact that “genes influence everything but strictly determine very little” because our environment primarily influences our development, contrary to what many believe (33). Take for example the era of Woodstock and hippies in the sixties, where rebellion against the old fashioned way of parents and grandparents was the society norm. The change didn’t happen because of varied gene expression from parent to child, but rather occurred with the eventful time period. The environment in which the children grew up in lead to racial mixing, women’s rights, minority rights, on top of international affairs, and that is what changed the pathway of the future generation away from the old fashioned. Although opposing viewpoints from younger versus older generations, the achievements of the younger generation show that although the future adults were “rebelling”, the continuous change was for the better. (Teen Ink on Generational Gaps)
Although the changes in the 1960s were mostly occurring with teenagers and young adults, the bottom line is that the environment can actually have a bigger influence on a child’s development and learning from an early age. The mimicry done by a child is crucial to development because at an early age infants and toddlers just do what they see. "Imitation is vital to the development of abilities ranging from language to social skills," explains Lisa Nalven, M.D., from New Jersey (http://www.parents.com/toddlers-preschoolers/development/behavioral/learning-by-imitating-you/). Since young children only do what they see, it can quickly be established as a habit and can transfer into a trait later in life. Additionally, from a study published in the Archives of Pediatrics and Adolescent Medicine, “children as young as two form dietary preferences based on their parent’s food choices” (http://www.rwjf.org/childhoodobesity/digest.jsp?id=8894).
Shivani Thakker (shivanithakker1357@gmail.com)
Part 2:
ReplyDeleteWhile evolution can still be considered a major player in the influence of parent to child traits, the genes transferred are still only a fraction of the influence. As Aaron noted, there have been studies that have shown that heritability is more prominent in determining skills, however with flaws. The fact of the matter is that children look up to their parents as role models, and “since parents are the strongest role model a child has” what they do and don’t do influence their children in ways they might not even notice initially (http://www.childup.com/blog/children-mimic-parental-behavior-good-and-bad). Whatever a parent does is deemed acceptable to a child’s mind, so everything that a child sees, they will most likely end up doing in the future. Even if children were taught by their parents to do something differently than the parent, the possibility of doing the exact same as a parent is much higher. After a role-playing scenario study with three to six year olds done by Madeline A. Dalton, Ph.D., from Dartmouth College, “of the 120 children participating in the study, 34 bough cigarettes and 74 bought alcohol” (http://www.consumeraffairs.com/news04/2005/tobacco_attitudes.html). The children actually had a 3.9 higher chance of picking up cigarettes if their parents smoked, and three times more likely to pick up alcohol if their parents drank alcohol once in a while in front of them. The staggering numbers from this study show that yes in fact the influence and mimicry of parents has a high possibility of being that perceived “inheritance” that was noted in the prompt.
Shivani Thakker (shivanithakker1357@gmail.com)