Over the years, scientists working in different fields of study have discovered vital pieces of information which support evolution. The most compelling evidence comes from comparing cell biology and biochemistry of several organisms. This analysis proves that the genetic code contained within the cells of most organisms is almost universal. Genetic analysis shows that cells from different organisms have some striking similarities. From the study of DNA sequence, organisms which are phylogenetically related have a similar DNA sequence. These similarities indicate a common origin. The more similar the DNA sequence between two organisms, the more closely related they are. Also, a look at the physiological processes taking place in all living organisms shows that they follow similar metabolic pathways – this is another point which supports evolution. The main physiological processes referred to here are fermentation and respiration. Lastly, all the living organisms require ATP to make energy - which is another factor supporting evolution. The fact that the major classes of living organisms (prokaryotes and eukaryotes) share a common metabolic pathway provides further support for evolution. The common pathway is glycolysis.
Glycolysis is a metabolic process involving the breakdown of sugars and carbohydrates to release energy in the form of ATP. It (glycolysis) takes place in both prokaryotes and eukaryotes. It is a well-known fact that the oldest organisms (which fossil records date to more than 3.5 million years ago) produced their energy through glycolysis. During that period, the presence of oxygen in the atmosphere was limited; therefore, the living organisms had to rely on a metabolic system which did not require the input of oxygen to make energy. These organisms were the prokaryotes. Since glycolysis does not require the presence of membrane-bound organelles, the prokaryotes took full advantage of this to process their energy. Consequently, prokaryotes made their energy through fermentation. The main product of fermentation is ATP. On the other contrary, eukaryotes - which evolved two billion years after prokaryotes – manufacture their energy through respiration process. Nonetheless, the similarities shared by eukaryotes and prokaryotes tend towards a common ancestry. Through cellular respiration, prokaryotic cells convert biochemical energy from nutrients into ATP. Waste products are released in the process. The process requires the use of sugars, amino acids, fatty acids and oxygen to make energy. As the Saint Leo community, there are a lot of things we can learn from the link between eukaryotes and prokaryotes, as well as the biochemical evidence which supports evolution.
For instance, the Saint Leo’s core value of respect requires us to treasure individual unique talents, while appreciating the diversity of people in the process. As seen from the evidence presented on evolution, living organisms share a common descent. Despite the evolution process, there are some processes which living organisms still share. This is a reminder that co-existence is an essential part of life because each organism has its unique capacities. It is also a reminder of the Saint Leo’s responsible stewardship which states that the creator blesses us with adequate resources. Therefore, it is our call to make good use of those resources to foster community development and achieve our goals. As a community, we must do all in our capacity to optimize those resources in order to achieve our mission and goals.
References
Dworkin, M. M., Falkow, S., Rosenberg, E., Schleifer, K.-H., & Stackebrandt, E. (2006). The
Prokaryotes: A Handbook on the Biology of Bacteria:Vol. 5: Proteobacteria: Alpha and
Beta Subclass. New York, NY: Springer.
Starr, C., Evers, C. A., & Starr, L. (2009). Biology: Today and Tomorrow Without Physiology.
Stamford, CT: Cengage learning .
