Evolution - Evidence - Entropy

Evolution is the result of a combination of several mechanisms which eventually contribute to changes in the genomes of a species. The most compelling and perhaps most well-known mechanism for evolution is natural selection in which certain mutations are "selected" for by the environment. Random traits are either beneficial or deleterious and eventually, the most advantageous traits will be passed down through generations eventually becoming more common in a population. Other key mechanisms include macro and microevolution, genetic drift, speciation, and notably, mutation. It's important to consider the significance of the environment and its role in interacting with mutations to drive evolution as a whole. Lastly, genetics, the figurative blueprint of life, is at the very core of evolution. The smallest alteration in a nucleotide or sequence has the potential to change the evolutionary course of an entire species.

Prior to Tuesday's discussion, I would have had the preconception that evolution is a highly researched and developed theory backed up by ample evidence. However, after class, I certainly agree with the statement that evolution is both a fact and a theory. We have both concrete evidence based on observation and proposed mechanisms that support the theory of evolution. Nevertheless, it's essential that we don't take evolution to be wholly factual as we still don't know everything about it. Specifically, our ability to predict the direction or effects of evolution is greatly flawed due to its seemingly random nature. 

Straying slightly from the assigned discussion prompts and returning to the class discussion, I thought I'd touch on the idea that evolution contradicts the second law of thermodynamics: that all matter in the universe increases in entropy in a closed system. Even before considering the fact that Earth is not a closed system as energy is constantly transferred from the sun, I still thought that evolution couldn't contradict thermodynamics. My mind first went to the point that often the causes and effects of mutations are pure randomness. Following this thought, my mind drifted further back in time to the chaos ensuing between molecules in prebiotic earth environments where very specific compounds would have interacted, seemingly by chance, to synthesize the first composites of life as we know it today. Although many of the lifeforms we recognize today are highly complex in terms of organization, from a molecular/genomic scale to a full-body scale, living organisms are constantly counteracting entropy by either consuming or releasing energy. In a rather simple example, this blog post has an organization and order to it; however, it took an input of energy to craft it. As Schreiber and Gimbel noted rather well, "In a nutshell, the synthesis of order exacts an energetic price: The cost of converting a relatively disordered water droplet into a more ordered snowflake is the release of heat to the environment, and the cost of embryogenesis is the conversion of ordered nutrients into less ordered waste products and heat. In the end, the processes of snowflake synthesis and embryogenesis always contribute more net entropy to the system as a whole." Their article is referenced below and is worth the read if any of you are interested in learning more about this argument.

Schreiber, A., Gimbel, S. Evolution and the Second Law of Thermodynamics: Effectively Communicating to Non-technicians. Evo Edu Outreach 3, 99–106 (2010). https://doi.org/10.1007/s12052-009-0195-3

Read the article here