Evolution: The Biocultural Approach

The term biocultural evolution explored on both cultural behaviors and biological developments influence evolution, meaning that any changes at one side could become a significant factor that leads a change to another (Lopreato, 1986). The biocultural evolution approach believes that biology, culture, and environment are interacting with each other closely and leading evolution. There are some significant evidence to suggest that humans are biocultural beings. For example, the physical characteristic changes help humans on adaptation in order for humans to survive in a certain environment and further develop their culture. Also, culture is an essential component can drive human biological evolution which a change in ways that species dealing with their food can cause a significant effect on their biological trait.

Firstly, according to Charles Darwin’s Theory of Evolution, he pointed out that the animals who are best suited for living in certain environments would have the greatest possibility of both surviving and reproduce in that environment. Therefore, biological developments influence human evolution and which human physical traits should be selected for and benefits humans. For example, human teeth, they can function up to millions of time throughout a lifetime, and the reason for that is because human ancestors had to repetitively chewing hard food and it required large jaws with lots of teeth in order to get more energy out of. However, they are messed up. And the reason for their ill-fitting is that compared to most animals is that human diets have undergone a rapid change. Archaeologists have had discovered stone tools and animal bones with cut and percussion marks around 2.6 million years ago which proves that human ancestors might have had develop hunting skills and get animal protein for them to get more energy. They also discovered that Homo habilis and Homo erectus had larger brains than the earlier australopithecines, and the brain expand in size from early hominins to early Homo was a significant biological evolution. Archaeologists also found evidences of cultural evolution such as campfire cooking and butchery that shows intelligence improvements. The hypotheses, Expensive tissue hypothesis (Aiello & Wheeler 1995) suggest that as food became easier to digest and nutrients became more easily available, and decreasing the energy to grow the digestive system allows humans to have more energy to grow other part. And natural selection causes the size of brains got larger, but ut the size of the brain does not mean increasing intelligence. So another hypothesis, Social Brain Hypothesis (Dunbar 2009) put forward that “In primates, there is a quantitative relationship between brain size and social group size (Dunbar 2009)”. Meaning that as hominins started living in larger groups, perhaps natural selection favored greater intelligence. In nowadays, technologies are developing rapidly and the food becomes even easier to absorb. So humans do no longer need large jaws and the jaws become small, and human teeth are messed up because the teeth do not have enough space to grow as natural expects, so they are so crowded and sometimes even misaligned. It is showing that biological evolutions and cultural evolutions, as well as the environment, are interacting and leads to human evolution. As a result, humans are biocultural beings due to the significant interactions between biology, culture, and environment.

Secondly, “human culture encompasses ideas, behaviors, and artifacts that can be learned and transmitted between individuals and can change over time (Cavalli-Sforza 1981)”. And combine with Charles Darwin’s Theory of Evolution, certain behaviors will be selected for if they contribute to the fitness of the species. Some behaviors are practice universally in all cultures, in other words, cultural universals. Cultural universals such as language, partnership ceremonies, and rituals associated with death, they are probably be selected for human. Although they might be expressed differently, but they are shared for all human culture which shows that evolution can be a key component of shaping human culture. However, culture is shaping evilution at the same time. For example, The Neolithic Revolution happened around 10,000 years ago, and it is where humans alter from hunter-gather society to one in which cultivate crops and to domesticate animals. People in that time have had more stable food resources, so they do not have to move around so much. Consequently, because people started to stay in one place the population began to grow in certain areas. As population started to grow, humans became more exposed to outbreaks of disease. And for those who survive, they are able to immune the disease as well as pass on their genes which shape the immune system within the community. After all, all these evidences show that evolution shapes culture, and vice versa.

Lastly, “The classic example of these interactions between cultural and genetic evolution is lactase persistence in adulthood (Creanza 2017)”. Most humans get all of their nutrition from human milk in their childhood, the babies produced lactase through infancy to digest their mother’s milk, but the genes that allow humans to digest this milk are typically switched off after weaned. However, after decades of archaeological research, it turns out that northern Europeans may have had develop cattle-rearing cultures that existed in the region about 6,000 years ago; therefore, their genes that code for the enzymes do not turn off which means that they can break down lactose in milk after their childhood. Those people who were able to digest milk protein are able to get the extra nutrition in a cold winter, they were more likely to survives and reproduce. The fact that “Northern European countries such as Sweden and Finland, with tolerance levels of 74% and 82%, respectively (Vuorisalo 2012)” is proofing the importance of culture effect on biological evolution, and so does the environment. As a result, culture and environment are critical determinants that cause biological evolution of humans. Culture, environment and biological changes entangle together are resulting in human evolution.

In conclusion, humans are biocultural beings because human evolution is closely related to both genetic evolution and cultural evolution. Lactase persistence demonstrates how culture and natural selection affect human evolution. And food processing developments that give rise to the change in human digestive system shows the relationship between human evolution and culture are closely related. And the research on humans’ messed up teeth indicates that due to technological improvements, humans are evolving rapidly. In this day and age, following the technological improvements humans are able to cure a lot of diseases and even change their genes. Once humans are able to fully control their genes, culture will be the key that drive human whether to end or long last.