According to the theory of evolution, all species of life on Earth share a common origin as a result of selection and variation over a long period of time. The parallels between similarities are a big unassailable proof that confirms evolution.
Darwin noted that species share similar traits, implying a common ancestor. To do this, he used homology to demonstrate that animals had identical bone structures, indicating a common ancestor. A human arm, a dog leg, and a pigeon wing, for example, all have identical bone structures, indicating a shared ancestor (Coyne, 2010). This similarity extends beyond what one can see with the eyes. A good example of the unseen similarity is the DNA which is available in all living organisms (Milot et al., 2011). Life started with the same DNA strand but over time, the DNA mutated and changed but this does not change the fact that all life forms started from the same DNA. For instance, a comparison of human FGF2 gene and the platypus genome reveals a similarity indicating that these two organisms share a common ancestor. Besides, the fin of a baleen whale looks exactly like the bone structure of a human arm suggesting that a baleen whale and human beings have a common ancestor (Milot et al., 2011). Therefore, the similarities that species share are greater than the variations, and this highlights that further back in time, any two-species shared a common ancestor. Species with closer similarities live closer to each other. Therefore, the absence of arbitrary vice points that all species had a common ancestor at some point. Therefore, evidence for evolution is watertight, and despite one’s conviction, it is undeniable that organisms share a similar ancestor; whoever that or it could be.
Figure 1: An illustration of homologous structures
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Similar bone structure can be observed figure above indicating that human beings, cat, what and bat have a common ancestor.
Milot, E., Mayer, F. M., Nussey, D. H., Boisvert, M., Pelletier, F., & Réale, D. (2011). Evidence for evolution in response to natural selection in a contemporary human population. Proceedings of the National Academy of Sciences, 108(41), 17040-17045.
Coyne, J. A. (2010). Why evolution is true. Oxford University Press.