Shenk refutes the painting of Lamarck's theories as "The Intellectual Loser", arguing that the lifetime acquiring of characteristics does have a bearing on the phenotype of the future. He essentially describes how Lamarck's "inheritance of acquired characteristics", was academically diminished with Darwin's theories and effectively killed by the discovery of DNA (155, 157). He then goes on to describe how the individual experience of a lifetime bears a greater effect on phenotype then the genes themselves as a result of significant histones and epigenomes (158). However, Shenk also also emphasizes the drive/motivation as playing a role in the growth into a "Genius", a principle which is not genetic or epigenetic in nature (120). Although Shenk earlier plays up the role of motivation in shaping your "Geniusness", he later moves to advocate for epigenetic patterns being the key cause. Consider the following questions: What role does the growth mindset have in comparison with that of epigenetic factors in determining success? How is the nature of Lamarck's comeback connected to the very examples of the Genius that Shenk mentions earlier in the novel, specifically in the realm of motivation?
Alex Nye (alex.nye95@gmail.com)
In Darwin's theory of evolution, the idea of natural selection in which random mutations create variations within a population and some of these characteristics, which are selective advantages, enable organisms to survive and pass on their genetic material to their offspring (Campbell 15-16). Lamarck’s general theory postulates that the organism itself is capable of altering the characteristics it passes down to its offspring (155-156). Lamarck basically argued that individuals had much more control over what their offspring would inherit. If true, this would not destroy the biological concept and theme of evolution but could potentially completely redefine our understanding of the restrictions that are supposedly set as well as the application of the theory.
ReplyDeleteBiological research in the mid-20th century discovered the hereditary material known as DNA, which itself is packaged in a chromatin structure (Campbell 321). The arrangement of the histone proteins that form the chromatin structure make up the epigenome. In 1999, Enrico Coen and his team studied two different-looking flowers that had identical DNA, but different epigenomes. Since Coen’s discoveries, other scientists like Marcus Pembrey, who studied the relationship between epigenetics and nutritional deficiencies and smoking, have discovered various traits and physical conditions that could be inherited after epigenetic changes in the lifetime of the parent (160). Choices like smoking could alter the epigenome, passing on acquired traits. The specific changes made to the chromatin structure include histone tail acetylation which increases transcription and replication at that region by loosening the forces between histones, histone tail methylation which increases the attraction between histones and decreases transcription and replication, and histone tail phosphorylation which counters the effect of histone methylation (Campbell 357-358). Now, researchers such as Pembrey and Dr. Lars Bygren are attempting to map out the epigenome to fully understand the implications of inheritance with respect to epigenetics and improve our understanding of all inherited characteristics and their implications (http://www.soulmedicineinstitute.org/TimeMag.pdf).
New understanding on the effects of epigenome inheritance signifies a profound change for our biological theme of evolution. Darwin's theory allowed parents to only pass on genes and not actually change the traits. Darwin's theory argues that those with the most suitable traits will survive, while Lamarck's theory argues that individuals can alter their traits to become more suitable to the environment. But, essentially, the end result is similar. Both theories support the idea that traits that are advantageous for an organism in a specific environment will be passed on. While slight modifications to the overall concept of evolution may be made, the continuation of advantageous traits still remains central to the theme.
Neil Edat (neil.edat@gmail.com)
Part 2
ReplyDeleteThe changes in epigenome also reflect the theme of continuity and change. In this case, the GxE interaction increases gene expression by altering DNA packaging and chromatin structure. The DNA inherited by the offspring exhibits continuity, but the affected epigenome exhibits change, not only within the parent organism, but also across generations. This continuity and change is closely related to evolution, but is also more applicable on the individual level in which histones are affected to increase transcription, and therefore the presence of specific traits, because the environment demands the changes.
Neil Edat(neil.edat@gmail.com)