Niche Construction - Implications

Implications

Niche construction has many implications for the human sciences, more specifically human sociobiology, evolutionary psychology, and human behavioral ecology. Standard evolutionary theory only allows for cultural processes to affect genetic evolution by influencing the individual, and depends on the ability of that individual to survive and pass on its genes to the next generation. Cultural processes are viewed merely as an aspect of the human phenotype and are not believed to be consequential to human evolution. Cultural diversity is believed to reflect variation in the environments that different populations of humans evolved in, and nothing else. This theory overlooks the fact that humans can modify their selective environments through cultural activity, thus feeding back to affect selection. "Cultural processes add a second knowledge inheritance system to the evolutionary process through which socially learned information is accrued, stored, and transmitted between individuals both within and between generations."

With the addition of language to the human culture came an increased mental capacity. This allowed for human adaptation of the environment to be a learned process, unlike nonhuman species, whose adaptive process is instinctual. This resulted in the acceleration of environmental, behavioral and genetic modifications. As niche construction advocate Derek Bickerton writes, "We could construct our niches without having to wait on interminable rounds of feedback between genes and behavior."

A theory on gene-culture coevolution calls for a more integrated relationship between genetic evolution and cultural processes than standard evolutionary theory. In this model, cultural activities are believed to affect the evolutionary process by modifying selection pressures. In other words, cultural change has the capacity to codirect its population's genetic evolution. Mathematical and conceptual models including investigations of language, handedness, the emergence of incest taboos, the coevolution of hereditary deafness and sign language, and sexual selection with a culturally transmitted mating preference demonstrate this theory. However, this theory is still dependent on standard evolutionary theory because it requires that cultural processes only affect genes directly, not allowing for any intermediate factors in the environment to interact with these processes at an evolutionary level. This theory exists on a dual inheritance system consisting solely of genes and cultural activity. "The dual inheritance system is a way to include interactions between nature and nurture in a tractable system." In most cases this theory works smoothly, however there are instances where cultural activities create changes in the abiotic environment that then affect selection pressures.

The speed at which humans are able to construct niches modifies the selection pressures and either genetic evolution or further niche construction can result. An example of genetic evolution through niche construction with the inclusion of an abiotic factor: Yam cultivators in West Africa cut clearings in forests to grow crops, but resulted in much standing water which attracted mosquitoes and increased the rate of malaria. This caused a modification to the selection pressure for the sickle-cell allele that protects against malaria. Evolutionary change is thus furthered. Example of further niche construction: Humans change the environment through pollution. The effects of pollution are alleviated by the innovation and use of a new technology. This cultural response to a constructed niche allows for a change in environment and a lack of change in genetics. Only if a new technology is not created or effective will evolutionary change occur. Humans are able to sustain adaptiveness by responding to ancestral niche construction through further cultural niche construction.

The addition of niche construction to the study of evolutionary processes forces scientists to accept that cultural activity is not the reason that humans are able to modify their environments, but is simply their primary means of doing the same thing that other species do. The fact that a large number of cultural processes are learned rather than genetically encoded into the individual, makes human culture an incredibly powerful method of niche construction. "Most of the time, cultural processes can be regarded as a shortcut to acquiring adaptive information, as individuals rapidly learn, or are shown, what to eat, where to live, or how to avoid danger by doing what other more knowledgeable individuals do."