Evolution as Presented by Charles

¶ … evolution as presented by Charles Darwin is based on three dynamics: natural selection, competition, and descent with modification. Descent with modification describes how species change, competition describes the pressure to change, and natural selection describes what changes occur.

This abstract makes the claim that natural selection, the process by which animals carrying reproductively beneficial traits slowly alter the genotype of a population by competing successfully, favors those species which are able to effectively adapt to a wide range of environmental changes. These genotypic advantages are obtained through descent with modification, which refers to minor mutations within a species that occasionally produce traits that improve on the "original" species.

The abstract goes on to make the claim that the more modification has occurred, the more fit the organism will be and hence the more favored by natural selection. This is because the changes produced by natural selection under competitive pressure will encourage changes that enable the organism to better adapt to its environment.

Finally, the abstract concludes by explaining that descent with modification produces a lineage of ancestry, so that closely related organisms can trace their lineage back to a common ancestor. The more closely related they are, the closer their common ancestor will be in terms of generations.

Critique

This abstract seems to make the common mistake of personifying evolution. A mindset that thinks of nature as "encouraging" or "trying" to produce a result is likely to make some serious mistakes.

The first and most serious is that any type of modification will produce a certain type of outcome. While it is true in the most general sense that helpful modifications are more likely to be retained, it is imperative to keep in mind that significant mutations to an organism are typically fatal, and that most genetic mutations that yield living organisms either cannot produce viable offspring or have an insignificant or slightly negative effect. Hence, pure quantity of variance within a species is meaningless, and the big decisions fall to fate: is species X capable of adapting to cataclysmic event Y? While the ability to adapt to diverse conditions is helpful, no significant change will occur in a species without significant pressure.