Postulates Of Natural Selection

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In the mid-1800s, Darwin and Wallace independently took careful observations of species near the South American content. And although both men were independently investigating, there are many overlaps in their observations and perspective in their respective papers – which focus on natural selection. The primary question of Darwin and Wallace’s papers were to investigate the nature of natural selection in various species and document the variation of characteristics amongst individuals in a population. For instance, which individuals were more apt to surviving in their environment by means of natural selection: from obtaining food to mate choice to producing viable surviving offspring? The premises of Darwin and Wallace’s papers build upon …show more content…
The following examples are only a few of the many examples presented in the papers. To address the first postulate (individuals varying in a population) it is interesting to incorporate Darwin’s observations on sexual selection. This observation also relates to the fourth postulate (survival and reproduction). When resources are available, Darwin states there is a rise in sexual selection, where individuals compete for mates, in a species. The results of “choice mate” relates to the 1st and 4th postulate in that these traits allows for some specific individuals to further reproduce because they have favorable traits. These sexual selecting traits can range from brighter feathers, louder/more pleasant song or dance, etc. This example, also ties into the 2nd postulate (some heritable variation is passed onto offspring). If heritable, those favorable traits can be passed down to future generations. All in all, this example of the birds combine all the four postulates and describe the importance of survival and the importance of reproduction for natural selection. In Wallace’s paper, he describes an observation of predation, antelopes and leg sizes (page 5). From Wallace’s assertion from that observation, a reader can extrapolate and integrate the four postulates. Antelopes with longer legs are more apt to survive by out running/escaping predators (3rd postulate). …show more content…
However, there are some differences within their arguments. Wallace’s outlook on natural selection and varying individual characteristics greatly relied on the individual’s adaptation for its environment for surival (for example, the bird “capable of very rapid and long continued flight” page 5). Darwin’s outlook the same topic greatly related to species competition for survival. Nonetheless, both outlooks as described in these papers focus on natural selection but it is important to notice the difference in perspectives. Other notable differences in arguments presented in these papers were the topics of sexual selection, and artificial selection – which were only by Darwin. Darwin’s explanation on artificial selection and sexual selection as part of natural selection further support these four postulates and are recognizable examples in real life. Darwin describes artificial selection on page 3 as “picking out individuals with any desire quality and breeding from them…”. This overlaps with the pigeon and dog breeding in breeding example (artificial selection) as discussed in class. For example, even today sexual selection is evident in many tropical bird species due to the differential success in mating due to varying characteristics. Wallace fails to mention details about sexual selection of artificial selection in this paper.

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