Key Difference – Evolution vs. Speciation
The terms evolution and speciation have very close links, although they have completely different definitions in the natural and social sciences. According to Darwin, evolution occurs mainly through the natural selection by which one species evolves with the greater inherited characteristics that make them well adapted its changing environment. However, Darwin’s theory of evolution does not clearly explain how new species give rise to another; the process called speciation. It is from this idea that the difference between these two concepts emerges. The key difference is that the process of adaption may be linked with the speciation, but not necessarily. In this article, the difference between the terms evolution and speciation will be discussed in brief.
What is Evolution?
Evolution is defined as the idea that the life on Earth evolved from a common ancestor and had gained various adaptations according to the changing environment with the time. Evolution is supported mainly by the studies and observations gathered over a long period of time. The genetic variations that occur with the evolution are passed down from one generation to next generation. Over time, the individual with greater adaptations will ultimately survive with the environmental changes. Charles Darwin is the first scientist to study the evolution. As a result of his studies, he suggested the theory of evolution, which explains how species evolve via the mechanisms of natural selection. According to Darwin’s theory, the adaptations are not created by experiences, but by the existing genetic differences among individuals. There are five causes that mediate the evolution, namely; mutation, gene flow, nonrandom mating, genetic drift and natural selection. Any of these agents can change the allele frequency thus facilitate the evolution.
What is Speciation?
Speciation is the lineage-splitting event resulting in two or more separate spices. Speciation occurs in two steps. The first population must diverge into two or more groups, and second, reproductive isolation must evolve to maintain the differences within the isolation population. Speciation may occur due to the geographical isolation, which is called allopatric speciation. Speciation that does not involve the geographic speciation is called sympatric speciation. It is found that the speciation is more likely to occur in geographically isolated populations. Reproductive isolation is a very important process of speciation. Genetic drift and natural selection can lead to speciation. Also, adaptive radiation, where species finds itself in a new or quickly changed environment may also lead to speciation.
What is the difference between Evolution and Speciation?
Definition:
Evolution is the idea that the life on Earth evolved from a common ancestor and had gained various adaptations according to the changing environment with the time.
Speciation is the lineage-splitting event resulting in two or more separate spices.
Causes:
Evolution is caused by mutation, gene flow, nonrandom mating, genetic drift and natural selection.
Speciation is caused by geographical isolation, natural selection, adaptive radiation that ultimately lead to reproductive isolation.
Image Courtesy:
1. Human evolution By Tkgd2007 (Own work) [CC BY-SA 3.0 or GFDL], via Wikimedia Commons
2. Simplified sketch of a speciation event – journal.pone.0042970.g007 By Hawlitschek O, Nagy ZT, Glaw F (2012) [CC BY 2.5], via Wikimedia Commons
