Kartic Godavarthy

Gene expression refers to the process by which the genetic information stored in DNA is converted into functional products, primarily proteins, that perform various functions within the cell. This process typically involves two main steps: transcription, where the DNA is transcribed into a messenger RNA (mRNA) molecule, and translation, where the mRNA is then translated into a protein by ribosomes.

Not all genes are expressed at the same time or in the same cells; rather, gene expression is a highly regulated and dynamic process that can be influenced by various internal and external factors.

From an anthropological standpoint, studying gene expression can offer insights into human evolution, adaptation, and diversity. Gene expression can also be influenced by social determinants like stress, education, and socio-economic status. Research has shown that stress can modify gene expression in ways that contribute to health disparities.

Significance in Anthropology

1. Cultural Evolution and Genetic Adaptation: Anthropologists study how certain genetic expressions have evolved in response to cultural practices. For example, the ability to digest lactose into adulthood is more prevalent in populations with a history of pastoralism. The gene for lactase, the enzyme that breaks down lactose, is expressed differently in populations with a long history of cattle domestication, such as in Indians, Northern Europeans and certain African tribes like the Maasai.
2. Ethnogenetics: Understanding the expression of certain genes can shed light on population migration and admixture. For instance, the frequency of the allele for sickle-cell anaemia is higher in regions where malaria is or was prevalent, indicating a historical adaptation.
3. Behavioural Genetics: Gene expression can influence behaviour, which in turn shapes cultural norms. For example, genes related to aggression, sociability, or risk-taking may have varying levels of expression in different communities, potentially influencing societal structures and norms.
4. Ecological Adaptation: Genetic adaptations to high altitudes have been studied among the Andean, Tibetan, and Ethiopian populations. In Tibetans, a gene called EPAS1 is expressed differently, allowing for more efficient oxygen utilization at high altitudes.

Examples of Gene Expression

1. Case of CCR5-Δ32 Mutation: This is a well-known mutation that provides resistance to HIV infection. This gene is found in higher frequencies in European populations, and anthropologists hypothesize that it became prevalent due to selective pressure exerted by the Bubonic plague or smallpox in medieval Europe.
2. Thrifty Gene Hypothesis: Proposed to explain the higher prevalence of diabetes in some populations, this hypothesis suggests that genes favouring efficient fat storage were advantageous during periods when food was scarce. Anthropologists use this to discuss how historical subsistence strategies may influence current health outcomes.
3. Warrior Gene (MAOA): Studies have suggested that some genepools have a higher incidence of the so-called “warrior gene,” which is associated with aggressive behaviour. This has led to debates within anthropology about the ethics and implications of linking genetics with behavioural traits, especially when such links could perpetuate stereotypes or be misused politically.

The study of gene expression is significant as it provides a biological basis for understanding the complex interplay between nature and nurture, individual and culture, and even past and present.