New Approaches to the Evolution of Human Behavior

            Agustin Fuentes puts forth a new perspective on the evolution of human behavior in “A new synthesis: Resituating approaches to the evolution of human behavior,” which appears in Anthropology Today. Traditionally, evolution has been analyzed through basic neo-Darwinian theory. This theory places the importance on natural selection and sexual selection as forces for evolutionary change. Individuals are “fit” if they have a reproductive advantage as determined by the environment. Agustin believes that sexual selection and natural selection are not the only important evolutionary theories for anthropology. He says, “Anthropology, in a general sense, should be concerned with evolutionary theory, an incorporate relevant perspectives well beyond those that focus exclusively on the action of natural and sexual selection as the prime drivers of evolutionary change” (Fuentes).

            Fuentes introduces three additional evolutionary theories: multi-inheritance systems theory, development systems theory, and niche construction. The multi-inheritance systems theory states that the evolution of human behavior is brought about through genic, epigenetic, behavioral, and symbolic inheritance systems. Genetic inheritance follows the basic model. Epigenetic inheritance, or the physiological processes of the body above the level of the DNA, is present in all organisms. Behavioral inheritance, or social learning, is present in some animals. Symbolic inheritance is present only in humans, and comes along with language and the exchange of information. The developmental systems theory says that human behavior evolves through the constant construction and influence of demography, social interactions, cultural variations, and environmental manipulations. Niche construction uses the tri-inheritance vision model, which states human behavior results from information processing at three levels, population genetic, ontogenetic, and cultural.

            Fuentes notes the disagreements between the three perspectives, but he sees the possibility of applying all three along with the neo-Darwinian point of view to the evolution of human behavior. Fuentes sets forth a framework for approaching the evolution of human behavior. Human behavior must be seen as an evolving system, with niche construction as a core factor for the evolution. Communication and the transfer of information are key to understanding human behavior. Natural selection may not always be the most prominent force of evolutionary change.

            Fuentes illustrates his theory with the bond between owner and pet. He says, “…it appears that humans can cast this physiological, social and symbolic bonding ‘net’ beyond biological kin, beyond reciprocal exchange arrangements, beyond mating investment and in particular, beyond our species…this is of anthropological interest” (Fuentes). The interactions between pet and human could be seen as reciprocal altruism. However, Fuentes posits the human-animal interactions are a complex system of physio-behavioral engagement and shared ecologies. Animal physiologies and human physiologies can affect each other with mutual interaction and modification within a shared social network and ecology.

            There is a definite biological effect of human-animal interactions, fitting with the neo-Darwinism perspective. Human interactions with pets also have a profound social effect. Fuentes uses the example of jumping of a bridge to save your dog instead of your brother, simply because you like your dog more.

            Fuentes’ example of human-pet relationships demonstrates the interaction of the various evolutionary perspectives. He says, “Using aspects of all of these lenses, we see that this human behaviour can be explained by a variety of complex approaches wherein no one ‘driver’ or ‘architect’ is privileged” (Fuentes). Neo-Darwinism can interact with the multi-inheritance systems theory, development systems theory, and niche construction.

            As a group, we agree with Fuentes’ analysis. Human social behavior cannot be explained simply by genetics. Our interactions with others are so complex, that genes cannot be the only source of behavioral change. Fuentes’ example of human-pet relationships is an excellent way of demonstrating the interaction of all of the theories. We would like to think that the bond and relationship between our pets and us is not simply good for passing on our genes, but also contributes to our happiness.
 
For more information about Agustin Fuentes and his work, see http://anthropology.nd.edu/faculty-staff/fuentes_agustin/index.shtml.

Works Cited

Fuentes, Agustin. “A new synthesis: Resituating approaches to the evolution of human behavior.” Anthropology Today. Vol. 25 (2009). W

Reciprocal Altruism

Reciprocal Altruism

            When discussing human behavior, altruism is always a topic that comes into questioning. Some people say that it is simply a human instinct, while others argue that it is imbedded into us genetically. Biology Professor Robert T. Trivers of Rutgers University states that altruistic behavior is, “behavior that benefits another organism, not closely related, while being apparently detrimental to the organism performing the behavior, benefit and detriment being defined in terms of contribution to inclusive fitness”  (39). Arguably, if a human runs into a building that is on fire to save a non-related human, it can be seen as an act of instinct, but if a human runs into that same fire to save one of his or her offspring, they are said to be saving there genes. Is there a genetic bond, or is it simply apart of human nature to risk a life to save a life?

            During Trivers study The Evolution of Reciprocal Altruism; he discusses three instances of altruistic behavior. The first is the behavior involved in cleaning symbioses, the second discusses the warning cries in birds, and the third and final instance discusses human reciprocal altruism. The focus of his study is to prove how kin selection, which is the altruistic behaviors that increase the donor’s inclusive fitness, that is, the fitness of the donor’s relatives, can be the reason for altruistic acts, but he also mentions how kin selection can be ruled out when people perform acts of altruism for those that they do not know. His model includes altruistic behavior of organisms of different groups, and he sheds light on how helping others will not only benefit the organism in need, but the organism performing the act as well.

            One concern that our group had was, scientist try to create an explanation for everything, why can’t altruism simply be an act that organisms commit because they genuinely care, rather than something that has to be for the benefit of their species? Evolutionary Biology Professor Richard Dawkins, formerly of Oxford University, provides somewhat of an answer to our question by explaining the idea of selfish genes and how they relate to reciprocal altruism in this short video.

http://www.youtube.com/watch?v=Wgh5ShwnMlU

He explains how genetically, organisms commit altruistic acts because of kin selection and the idea of survival of the fittest, which essentially means the survival of genes. But unlike Dawkins, Trivers gives an example on how organisms without kin selection work together in order to benefit one another. In his example of cleaning symbioses, the symbiotic relationship may be categorized as mutual, commensal, or parasitic in nature. In each instance, the relationship between the different organisms proves that a genetic bond between organisms is not needed in order to commit altruistic acts.

            When looking at warning calls in birds, this altruistic behavior is only used to protect one’s mate, offspring, or another bird very close in kin. This goes back to the idea of saving ones genes, and even though the two parent birds are not directly related, it is beneficial for both the mates to survive in order to produce more offspring. Trivers also explains that if a bird does not use a warning call for other non-related birds, it could be a disadvantage to that bird. If a predator eats a near by bird, it is more likely to eat him as well. There for altruistic behavior can be beneficial to both the organism performing the act, and the recipient receiving the help.

            With the example of altruism in other organisms, human reciprocal altruism provides an insight as to why some organisms might lower their chances of “fitness” in order to increase the “fitness” of another. Kin selection can be the answer as to why some people risk their lives in order to save family members, or their genes, but this is not the case for all acts of altruism. Some people commit these acts of kindness in order to gain favors from those of whom they help, it is kind of like the motto, “you scratch my back, and I will scratch yours.” According to Trivers, reciprocity is more expected from kin than non-kin due to the genetic bonds, but not all acts of altruism have to be for the benefit of a species. So is this act of human behavior simply done in order to increase the “fitness” of an organism, or can it be said that people commit these acts out of the kindness of their hearts?

Works Cited

Trivers, Robert L. "The Evolution of Reciprocal Altruism." Quarterly Review of Biology 46.1 (1971): 35-57. JSTOR. The University of Chicago Press, 7 Apr. 2008. Web. 27 Mar. 2011. <http://www.jstor.org/stable/2822435>.