Buy essay on Climate changes

The Claim
Powerful and often abrupt climate changes on the Earth several millions of years ago had a great impact on the processes of human evolution.

Good Evidence
The article “The Pulse That Produced Us” by Elizabeth S. Vrba is interesting and well grounded material. The author states that she follows not the Darwinian hypothesis that the process of evolution is mainly the product of competition between all the species, but the hypothesis of her own. She state that in the course of time thousands of species vanished, other ones appeared instead. And something definitely happened 5 million years ago which gave a strong push to the old cast members (small-bodied australopithecines, for example) off the stage and introduced new ones (Homo species). This process she called a turnover-pulse. She suggests that in case of right conditions evolution within the threatened population may produce a new species. On the whole I tend to consider that the claim that climatic changes take the main part in the human evolution is substantiated in this online source because the processes are thoroughly described and many research data and means of investigation as well as references to the hypothesis of other scientists are pointed out.
Reading the article from the next online source “Human Evolution: Climate Change and Human Evolution” by Anna K. Behrensmayer we understand that the author of the book stated that continuous stressful situations in the life of our ancestors such as abrupt and cardinal climate changes of those times provoked human evolution. It was a real try out for those who had to live and a crash for those who had to die. The author states that humans learned how to adapt to climate changes and that was the main reason of their success. In the article we may get some necessary data for better understanding of the processes which took place on the Earth of that time period. Marine-core records indicate, for example, that a cooler and more variable global climate regime started approximately 3 million years ago (Ma), in the course of time intensifying into northern continental glacial cycles by 1 Ma. We may observe that climate shift between 3 and 2, 5 Ma coincides of the origin of Homo Sapiens. In my opinion this piece of evidence is really good. Also in the article it is stated that though it is much harder to trace the climate change’s influence on human evolution through the research of the continental basins which contain hominine fossils, it is possible to make research through paleoclimatic proxy evidence which includes isotope, pollen, mammal faunas and lake versus land deposits. The author also maintains that such research data need further investigation. Nevertheless a lot of provable information with references to literature sources makes us believe that the claim that climate changes influenced human evolution is substantiated.
Poor Evidence
Rick Potts, who works as paleo-antologist at the Smithsonian Institution in Washington states that climate changes coincide with such human evolution milestones as, for example, walking on two feet and some developments in tool-making. This is the main point he underlines. To my mind this online evidence is not substantiated enough because the article definitely lacks proved information and research data. Reading the article we only get the bare opinion of the author and the topic still needs much further investigation. Moreover in the online source I failed to find correct information how the data the statements of the author are based on were gathered.
Generally we suppose that it is not always the best way to make any kind of research work using only online resources. In the Internet space it is difficult to rely upon the given information even if all the references seem correct and respectful. We felt not comfortable operating with online archeological material. Moreover I believe that my critical evaluation of the article could depend much on the structure and readability of it; and sometimes readability and correct language style is not enough for the piece of information to be considered a piece of good evidence.
Conclusion
Although it is not easy to tell which of the online sources are reliable and which are not, we managed to analyze some of them critically. The article “The Pulse That Produced Us” by Elizabeth S. Vrba proved to be well grounded and seemed quite reliable due to detailed description of the main process of evolution which appeared to coincide with some milestones in the human evolution. “Human Evolution: Climate Change and Human Evolution” by Anna K. Behrensmayer we find well substantiated too; the article contains some research data and necessary references to materials used in the article. As for the online source describing the points of view of Nick Potts, we believe that this article provides us with not enough information on the topic; moreover there are no research data as well as methods of investigation. Probably the book of Nick Potts may be very useful and the claim that climatic changes affect human population is substantiated there, we can’s tell the same about the online article.