User:Nvega004/Biological specificity

 Adding: Biological specificity within Homo Sapiens 

Homo sapiens have many characteristics that show the biological specificity in the form of behavior and morphological traits.

Morphologically, humans have an enlarged cranial capacity and more gracile features in comparison to other hominins. The reduction of dentition is a feature that allows for the advantage of adaptability in diet and survival. As a species, humans are culture dependent and much of human survival relies on the culture and social relationships. With the evolutionary change of the reduction of the pelvis and enlarged cranial capacity; events like childbirth are dependent on a safe, social setting to assist in the childbirth and a birthing mother will seek others when going into labor. This is a uniquely human experience, as other animals are able to give birth on their own and often choose to isolate themselves to do so to protect their young.

An example of a genetic adaptation unique to humans is the gene APOE4 on chromosome 19. While chimpanzees may have the APOE gene, the study “The apolipoprotein E (APOE) gene appears functionally monomorphic in chimpanzees” shows that the diversity of the APOE gene in humans in unique. The polymorphism in APOE is only in humans as they carry alleles APOE2, APOE3, APOE4; APOE4 which allows human to break down fatty protein and eat more protein than their ancestors is also a genomic risk factor for Alzheimer’s disease.

There are many behavioral characteristics that are specific to homo sapiens, such as the childbirth mentioned above, specific and elaborate tool creation and use and language. Humans do not simply communicate; language is essential to their survival and complex culture. This culture must be learned, is variable and highly malleable to fit distinct social parameters. Humans do not simply communicate with a code or general understanding but adhere to social standards, hierarchies, technologies, complex system of regulations and norms and must maintain many dimensions of relationships in order to survive. This complexity of language and the dependence on culture is uniquely human.

Intraspecific behaviors and variations exist within Homo sapiens which adds to the complexity of culture and language. Intraspecific variations are differences in behavior or biology within a species. These variations and the complexity within our society lead to social constructs such as race, gender, and roles. These add to power dynamics and hierarchies within the already multifaceted society.

Intraspecific hybridization, hybridization between sub-species within a species.

Interspecific hybridization, when two species within the same genus generate offspring. Offspring may develop into adults but may be sterile.

 Adding references: 

1.    McIntosh AM, Bennett C, Dickson D, et al. The apolipoprotein E (APOE) gene appears functionally monomorphic in chimpanzees (Pan troglodytes). PLoS One. 2012;7(10):e47760. doi:10.1371/journal.pone.0047760. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3480407/

2.    Bleibtreu, H. K. (1969). Evolutionary anthropology: a reader in human biology. Boston: Allyn and Bacon. https://catalog.hathitrust.org/Record/001491836/Home

3.    Hallinan, M. Brennis., University of California, B. Department of Anthropology. (1980). Culture and human nature: an anthropological inquiry into the human phenomenon.https://catalog.hathitrust.org/Record/100705294/Home

4.    Lee S-H with Yoon S-Y (2018) Close Encounters with Humankind: A Paleoanthropologist Investigates Our Evolving Species. New York, NY: W.W. Norton.