An adaptation is any alteration in the structure or functioning of an organism (or group of organisms) that improves its ability to survive and reproduce in its environment. Adaptations occur in response to stressors or changes in the environment in which the organism lives. Stressors can be abiotic (climate or high altitude), biotic (disease), or social (war and psychological stress). All organisms, including humans, have the ability to adapt biologically, which is referred to as biological plasticity. However, what makes humans unique is the extent to which we rely on culture to adapt to our environment.
Definition: adaptation
Any alteration in the structure or functioning of an organism (or group of organisms) that improves its ability to survive and reproduce in its environment.
Definition: biological plasticity
The ability to adapt biologically in response to the environment.
Definition: stressors
Something that causes strain or tension.
Biological Adaptation
Other species rely primarily on biological adaption for living in their respective environments. Biological adaptations can be short-term, long-term, or genetic. Which type of biological adaptation is activated often depends on the severity and duration of stressors in the environment. Short-term acclimatization can occur within seconds of exposure to a stressor. This type of response quickly reverses when the stressor is no longer present. Imagine stepping out of an air-conditioned building or car into a 90-degree day. Your body will quickly begin to perspire in an attempt to cool your body temperature and return to homeostasis. When the temperature declines, so will your perspiration. Tanning, which can occur in hours, is another short-term response, in this case, to increased UV-radiation exposure. Tans are generally lost during the months when UV-radiation decreases.
Developmental acclimatization occurs during an individual’s growth and development. Note that these cannot take place once the individual is fully grown. There is usually a “magic time window” of when developmental acclimatization can occur. This adaptation can take months to years to acquire. One example of this is the efficient respiratory system of those who have grown up at high altitudes. Those who were born at high altitudes tend to develop larger lung capacities than those who move there later in life.
Note
A developmental adjustment can occur in response to cultural stressors as well. Intentional body deformation has been documented throughout human history. The ancient Maya elite used cradleboards to reshape the skull. Footbinding in China, now an illegal practice, was considered a mark of beauty and enabled girls to find a wealthy spouse.
Genetic adaptations can occur when a stressor is constant and lasts for many generations. The presence of the sickle cell allele in some human populations is one example. Keep in mind that genetic adaptations are environmentally specific. In other words, while a particular gene may be advantageous to have in one environment, it may be detrimental to have in another environment. The sickle-cell allele is a genetic adaptation in response to living in an environment where malaria is prevalent. However, for those living in non-malarial environments, it is no longer advantageous and actually a serious disease.
Cultural Adaptation
A cultural adaption is the knowledge or behavior that enables humans or groups to adjust, survive, and thrive in their environment. One way humans culturally adapt to their environment is through the use of tools. As mentioned earlier in the chapter, some non-human species do have a rudimentary culture as evidenced by their use of tools. Whether it is dolphins using sponges to protect their beaks when hunting fish on the ocean floor, chimpanzees using sticks to "fish" for termites, otters using a rock to break open a shell or humans hunting with a bow and arrow, the use of tools is a cultural adaptation that improves the species chances of survival in their environment. Humans, however, "use culture instrumentally...to fulfill their basic biological needs for food, drink, shelter, comfort, and reproduction" (Kottak 2012, p. 21) as well as fulfilling basic psychological and emotional needs.
Definition: cultural adaptation
The knowledge or behavior that enables humans or groups to adjust, survive and thrive in their environment.
Figure \(\PageIndex{1}\): Cultural Adaptations - Tool Use
Image 1: Sea Otter uses a rock to break a shell open, 2008, by Brocken Inaglory under CC BY-SA 3.0.
Image 2: Bonobo at the San Diego Zoo "fishing" for termites, 2005, by Mike R. under CC BY-SA 3.0.
Image 3: Macaca fascicularis aurea using a stone tool, 2013, by Haslam M, Gumert MD, Biro D, Carvalho S, Malaivijitnond S under CC BY.
Image 4: Young Man with a Bow and Arrow, Lubwa, Zambia, c1905-1940, by Unknown under Public Domain.
Cultural adaptations can occur at any time and may be as simple as putting on a coat when it is cold or as complicated as engineering, building, and installing a heating system in a building, or building a space station for human habitation. Cultural adaptation has enabled humans to survive in harsh environments. However, not all cultural adaptations have been beneficial. While the goal of adaptive traits is to enhance human ability to be successful and survive in their environment, some traits have become maladaptive. That is they have become more harmful than helpful and could actually threaten the survival of the people. One example is the use of air conditioners. Although air conditioners improved our lives and made it easier to live in hot and humid conditions, older air conditioners released chlorofluorocarbons and contributed to the depletion of the ozone layer which protects us from harmful ultraviolet rays. Over a long period of time, this would have a negative effect on life on earth.
Figure \(\PageIndex{2}\): Self-portrait of Tracy Caldwell Dyson in the Cupola module of the International Space Station observing the Earth below during Expedition 24, 2010, by NASA/Tracy Caldwell Dyson under Public Domain.
BIBLIOGRAPHY
Kottak, Conrad P. Mirror for Humanity: A Concise Introduction to Cultural Anthropology. New York, N.Y: McGraw-Hill, 2012.
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