Charles Darwin wrote that a pattern of evolution is similar to a tree, as it branches out in various directions with the elements nearby each other in the tree being those more alike than those far apart. According to the text “one species giving rise first to two or three varieties, these being slowly converted into species, which in their turn produce by equally slow steps other species, and so on, like the branching of a great tree from a single stem, till the group becomes large” (Freeman and Herron 47). Meanwhile, this pattern of development is evident in successful species resulting in speciation and variables or an entire new species. The branch of the tree is evident in the evolution of the real world as species diversify in this manner while exploiting various ecological opportunities. Divergent species diverge and continue their unique pattern of development; they do not remerge to generate what would effectively be a network. This is another reason why the analogy of a tree works best to describe the patterns of evolution.
The new material in the text, compared to the existing material described in earlier discussions, is more complex and detailed. The hierarchical classifications can also be applied to the tree, while phylum, classes, orders, and the other elements of the taxonomy are represented by various locations in the branches (with the smaller classes being further down the branches and the original patterns being closer to the trunk.) In addition to the described elements, the consideration of the branching tree in the patterns of evolution is further useful in explaining comparative anatomy; this also served to help explain evolution in its early years of development.
Presently, many patterns of evolution are considered by modern science, based on Darwin’s theories. Natural selection can lead to the development of new species as described, while patterns of evolution can be classified in terms of divergent and convergent evolution as well as co-evolution. For example, similarities in species have led scientists to assume that the numerous subspecies have resulted from a sole original species; this is an evolutionary pattern, while a common process in an evolution pattern (for example) is adaptive radiation. Adaptive radiation is common when species successful invade an isolated area with little competition from other species; when new environmental elements in this new area exist while little to no threats are present, the species will evolve.
Patterns of evolution can vary substantially, and as mentioned, there are multiple classifications. Adaptive radiation is an example of divergent evolution, which is the process of two related species becoming increasingly variant. This naturally results from each being exposed to different conditions which demand different traits for optimal living. Meanwhile, co-evolution is the joint variance of two or more species which interact in the environment. Predator animals and the prey which they seek commonly co-evolve, as well hosts and parasites, as the result of being exposed to similar conditions. Naturally, all of these areas contribute to the pattern of evolution, represented in the tree model. All of these areas, divergent, convergent, and co-evolution are examples of different ways which organisms change according to the demands and opportunities of the environment.
Overall the elements of previous and recent discussions unite to better facilitate a more complete perspective. The diversity of life is great, while patterns of evolution suggest they are becoming greater still. The ability for species to improve and become more complex has taken the biodiversity spectrum from the simple and less capable organisms to those which are capable to feats unknown of in earlier times while revealing the biological potential to make the most of a changing environment. So long as the Earth and the environment does not change too quickly and too chaotically, the pattern of evolution suggests that a new branch can be extended to meet the changing needs of the environment. Darwin realized this while he was finalizing his theory in the Origin of Species and organizing it in a way which could be better explained, and he chose the tree model so that people could understand the shifting directions yet common processes of evolution (Darwin). This pattern shows that all organisms possess the same potential to change in such a manner, however they are bound by their biological and evolutionary past in terms of their optimal environment and conditions. The continuing trends will give rise to additional subspecies, and eventually new species (as it is common knowledge that new species are continually discovered even in modern times,) and Darwin predicted this pattern will continue throughout life on Earth without any foreseeable stopping point.
Darwin’s thoughts were logical and have not been proven incorrect over the many years his theories have remained the focus of biological science and evolution. Critics have been able to make strong claims, however these claims have not been substantiated. Until they are, they remain little more than speculation while the pattern of evolution and tree model remains accepted.
Works Cited
Darwin, Charles. The Origin of Species. Literature.org. 2005. Web.
Freeman, Scott and Jon Herron. Evolutionary Analysis. Upper Saddle River: Prentice Hall, 2006.