How Culture Drove Human Evolution - Essay Example

Human Evolution Heinrich in an article A Cultural Species: How Culture Drove Human Evolution explains how natural selection influenced human learning and how this resulted into cultural evolution and coevolution the cultural gene. According to Heinrich, before agricultural evolution, humans spread throughout the globe, Therefore surviving in the different habitats did not only depend on the specific genetic configuration, but depended also on large body of cultural information transmitted across the groups, abilities, and other skills that no human could have comprehended alone. Thus the lack of cultural knowledge made many individuals to perish in new habitats. Heinrich used the theory that capacity for knowing is an important adaptation to extract adaptive information from the environment, which is still relevant to the current human interactions. The research recognized that considering the cultures central to human life resulted in a formidable evolutionary theory in status psychology. However, considering that humans have to depend on information for survival, the huaman specks must have evolved in line with social status that occurs parallel to dominance, and is related to affective and cognitive processes (Heinrich, 2011). In such cases, where a species depends on learning from others to a large extent to improve some aspects of its behavior, such process will effectively alter the environment faced by the natural selection that impacts on the human genes. Therefore, as humans continuously use their cultural learning abilities, the abilities give rise to continued cultural evolution. Such continued cultural evolution leads to development of complex adaptive practices, techniques, tools and other bodies of knowledge related to human behavior, and edible plants in such habitats (Heinrich, 2011). This aspect is relatively new and explains how humans adapt and survive in extreme situations as studied under anthropology. Consequently, cultural adaptations continue to improve over many centuries, which mean that when humans are stripped off their cultural adaptation, they become hopeless species that can easily be wiped. Sturt (1) explains that human evolution has higher probabilities of being a continuous process and not according to the currently accepted model of distinct changes that characterize a shift from one species to the next. Therefore, species would be best described to be semi homogenous over time, which is a new shift from what is already known in evolution regarding the shift from one species to the other in distinctly defined times. According to Sturt, there is no smooth development in morphology; what is perceived to be skeletal change results from a small flaw in the long genome configuration. The stability in certain species as observed would be explained by stability between marked changes in such genome flaws. The fossils currently known to humans offer an exaggerated perception regarding evolution in that the fossils are widely spaced in time, implying the difference between such fossils represent a continuous evolution processes to differentiate one species from the rest. Sturt (2) explains there is no much difference between the current human species and the Neanderthal man since they are only separated by several hundreds of years. Similarly, the brain followed the same evolutionary process, and it is the physical part in which rational decisions can be coded and decoded to differentiate between man and ape. Since such physical factors have to be passed down the genetic tree, it would follow that if these features increased the survival of the individual possessing them, they are gradually enhanced till the whole population acquire them through natural selection. Evolution thus involved significant development and spread of brain features through a natural selection process explaining what turned the earlier animal behavior to human behavior enhanced by a life learning process and a favorable climate. Schaffner (2008) in an article Evolutionary Adaptation in the Human Lineage explained that any trait that undergoes a natural selection has to meet the following conditions: the trait must be beneficial to the species; it has to increase the probability that the organism reproduce and survive, and it has to be inheritable to facilitate passing the traits to an offspring down a hierarchy. Though positive selection is not the only means through which humans evolved, in humans a large section of mutations are perceived to be selectively neutral imparting no cost or benefit to the bearers of such traits. As advantageous alleles under positive selection became more prevalent, the alleles leave behind unique patterns or genetic variation in the DNA sequence (Schaffner, 2008). As Schaffner elaborates, assuming that at the beginning there was a large number of individuals whom before the selection occurred had millions of chromosomes all in different variations, then as Schaffner (2008) explains, when an advantageous allele arises in the population as a mutation on a copy of chromosomes, it would follow that the following generations and descendants of the chromosome copy that include the allele and the nearby hitching allele undergo a selective sweep and become more common in the population (Schaffner, 2008). However, the chromosome is not passed down as a whole, but with time, due to recombination, the segments of the chromosome are inherited, implying the population with the selected allele reduces with time. This theory is close to Charles Darwin and Alfred Wallace theory of evolution, which explains the passing down of traits through genetic mutation. It is important in anthropology as it explains common traits in communities. However, the idea of selective sweep in evolution resulting to a dominant population with similar traits may be understood to be a new concept in evolution that as Schaffner (2008) explains gained root much after discovery of human genome that acts as a framework for human genetics. Quinn (2012) in an article, The Ongoing Evolution of Humanity explains that evolution is an ongoing process leading to changes in all animals and in the natural world. According to Quinn, there are increased beliefs that humanity has attained the pinnacle of evolution and has stagnated, though Quinn asserts that the current human species is evolving at a much faster rate than ever. Thus changes that took long to be perceived several decades ago are currently manifesting themselves at a faster rate than expected. For example, in 2002 many international broadcasting media made a remark that the blond gender was in regression and would lead to disappearance of all blonds in the world, which was based on evidence from the World Health Organization, and research by German researchers, though WHO later denied being part of such a research (Quinn, 2008). However, Ackerman an associate professor in the Department of Archeology Cape Town University noted that there is enough evidence of evolution in the current diseases susceptibility and resistant, which sited the balancing action that seemed to support the sickle cell anemia prevalence in some parts of Africa and its protection against Malaria (Quinn, 2008). In addition to other research that support and identify some selective pressures effective in shaping modern humans. In addition, a research involving women participating in Framingham Heart Study revealed that if the current trends are to proceed unabated and with no cultural changes that would influence child bearing patterns , then in the next ten years, the average Framingham woman would be much shorter , more heavier, give birth earlier, and enter menopause much later in life (Quinn, 2008). Therefore, the research revealed that the rate of evolution is much slower, but compared to what is perceived in plants and animals, human beings do not have any particular exception in the evolution process. This study is important in anthropology in that it explains the current trends in diseases such as sickle cell in Africa, and group of Africans who have developed resistance to Malaria and HIV, two leading killer diseases globally. Quinn argues that such trends indicate possibility genetic changes in humans that would offer enough evidence for human evolution. This is a new concept in evolution, which offers current practical examples. Summary The four articles present interesting perspectives regarding human evolution. Quinn (2008) and Henrich (2011) conquer on the fact that evolution in humans is continuous, and cannot be separated into distinct stages as the Darwinism theory attempts to achieve. Heinrich explains the importance of culturally transmitted knowledge that led to development of skills on how to survive in some harsh conditions, failure to which such individuals perished. Quinn (2008) utilizes the evidence observed particularly in Africa, regarding resistance to diseases such as Malaria and HIV, which have been killer diseases globally as evidence of evolution in human genetics. On the other hard Sturt (2010) explains that evolution must have been and still is a continuous process that cannot be easily perceived as there are no particular stagnation stages, making species homogenous through the process. Thus according to Sturt, the current archeology that puts more emphasis on certain discovered fossils leads to misplaced conclusion as these species are widely separated in time, which implies that the time was enough for the change in skeletal and brain structure to occur, but such fossils do not portray any stagnant period in evolution. Schaffenr (2008) on the other hand explains the role of positive natural selection that increases beneficial traits in the society to have had a huge impact in survival of species. Similar to Darwinism, this approach explains that such survival adaptations increased the chances of specifies to survive in different environments, while negative selection getting rid of those that did not fit the environment for survival. However, evolution theories have several questions that still remain unanswered: i. It is not clear how animals can evolve into something else considering that humans are considered to have evolved from very simple organisms ii. No one has enough proof or has seen any genuine example of evolution on a species producing a variedly different species, putting to question how such evolution would have come about in the current human species. iii. The few numbers of fossils discovered as proof of the earlier human species do not adequately explain how the human race evolved to the current species, leaving too many gaps to be filled iv. Though negative selection is credited for extinction of some species, there is scientific evidence that natural catastrophes resulted in extinction of some species, which puts into question the validity of evolution theories. With these questions, more has to be done regarding species evolution to come up with a more credible and elaborate explanation that leaves no gaps in the species evolution processes, for evolution to be more appealing to the general public apart from historians. Work Cited Heinrich Joseph, A cultural species: How Culture Drove Human Evolution, American Psychological Association, 2011 http://www.apa.org/science/about/psa/2011/11/human-evolution.aspx Accessed 30th April, 2013 Quinn Donald, The Ongoing Evolution of Humanity, 2012, 10 Sept. http://digitaljournal.com/article/332571 Accessed 30th April, 2013 Schaffner, Stephen. & Sabeti, Pardis.  Evolutionary adaptation in the human lineage. Nature Education 1(1) (2008) http://www.nature.com/scitable/topicpage/evolutionary-adaptation-in-the-human-lineage-12397 Accessed 30th April, 2013 Sturt A.C., Human Evolution as a Continuous Process, 2010, http://www.churingapublishing.com/fincontevolution.doc.pdf Accessed 30th April, 2013 Read More