Syllabus: Paper I > 2.5 Kinship > Kinship terminology and theory
Assumptions for Genetic Equilibrium — 2023 Paper I
Question · 2023 · Paper I · 15 Marks
What assumptions must be met for a population to be in genetic equilibrium ? Explain the importance of genetic equilibrium.
Model Answer
VAID ICSIntroduction Genetic equilibrium refers to the condition where allele and genotype frequencies in a population remain constant from generation to generation. This concept is mathematically formalized by the Hardy-Weinberg (H-W) Principle (1908). For a locus with two alleles (dominant 'A' with frequency p, and recessive 'a' with frequency q), the equilibrium is expressed as:
- Allele frequency: p + q = 1
- Genotype frequency: p² + 2pq + q² = 1
Assumptions for Genetic Equilibrium For a population to remain in Hardy-Weinberg equilibrium, five strict conditions (forming an 'ideal population') must be met:
- Infinite Population Size: The population must be large enough so that random chance (Genetic Drift) does not alter allele frequencies.
- Panmixia (Random Mating): Individuals must mate randomly without regard to genotype or phenotype (no sexual selection or strict endogamy).
- No Mutation: There must be no alteration in the DNA sequence creating new alleles.
- No Gene Flow (Migration): There must be no immigration or emigration of individuals that would introduce or remove alleles.
- No Natural Selection: All genotypes must have an equal chance of survival and reproduction.
Importance of Genetic Equilibrium in Anthropology
- Functions as a 'Null Hypothesis': No human population perfectly meets all H-W assumptions. Therefore, it serves as a baseline. If observed genotype frequencies deviate from the expected $p² + 2pq + q²$, it mathematically proves that evolutionary forces are actively shaping that population.
- Measuring Natural Selection: By calculating deviations, anthropologists can measure adaptive evolution. Example: The persistence of the deleterious Sickle Cell allele (HbS) in malaria-endemic regions of Africa deviates from H-W equilibrium, proving that natural selection is favoring the heterozygote (Balanced Polymorphism).
- Detecting Genetic Drift and Founder Effect: H-W equilibrium helps identify populations shaped by historical bottlenecks. Example: Deviations in the Amish population of the USA show the impact of the Founder Effect on traits like Ellis-van Creveld syndrome.
- Analyzing Marriage Practices: Deviations help anthropologists quantify the biological impact of cultural practices like strict caste endogamy or consanguineous marriages, which increase homozygosity (inbreeding depression) beyond H-W expectations.
Conclusion The Hardy-Weinberg equilibrium is the foundational mathematical framework of population genetics. By providing an idealized model of a non-evolving population, it allows biological anthropologists to accurately detect, measure, and understand the evolutionary and demographic forces shaping human diversity.
Want feedback on your answer?
Join the Anthropology workshop or get structured answer-writing guidance from VAID ICS.
UPSC Anthropology Optional 2023 — Paper I
28 questionsSyllabus: Paper I > 6. Anthropological Theories > Globalization and culture
Syllabus: Paper I > 9.3 Mendelian population and Hardy-Weinberg law
Syllabus: Paper I > 1.6 Phylogenetic status, characteristics and distribution > Australopithecines
Syllabus: Paper I > 5. Religion > Anthropological approaches to the study of religion
1(b) Cultural impact of Iron Age
10 Marks150 words
Syllabus: Paper I > 1.8(b) Cultural Evolution > Iron Age
1(d) Customary laws and Environmental conservation
10 Marks150 words
Syllabus: Paper I > 4. Political Organization and Social Control > Customary law
Syllabus: Paper I > 8.1 Research Methods > Fieldwork tradition in Anthropology
Syllabus: Paper I > 12. Applications of Anthropology > Nutritional anthropology
1(e) Gene expression
10 Marks150 words
Syllabus: Paper I > 1.7 The biological basis of life > Gene and protein synthesis
Syllabus: Paper I > 3. Economic Organization > Impact of globalization
5(c) Glottochronology
10 Marks150 words
Syllabus: Paper I > 7. Culture, language and communication > Language change
Syllabus: Paper I > 1.4 Human Evolution and emergence of Man
Syllabus: Paper I > 1.8(b) Cultural Evolution > Mesolithic
Syllabus: Paper I > 2.3 Marriage > Rules of marriage
5(d) Menopausal symptoms
10 Marks150 words
Syllabus: Paper I > 11.1 Relevance of menarche, menopause and other bio-events to fertility
3(c) What is mixed-longitudinal method of studying human growth ? Discuss its merits and demerits.
15 Marks
Syllabus: Paper I > 10. Human growth and development > Methodologies for growth studies
Syllabus: Paper I > 1.8(b) Cultural Evolution > Palaeolithic
Syllabus: Paper I > 12. Applications of Anthropology > Forensic Anthropology > Personal identification
Syllabus: Paper I > 6. Anthropological Theories > Culture and Personality > National character studies
5(a) Polygenic Inheritance
10 Marks150 words
Syllabus: Paper I > 9.2 Mendelian genetics in man > Polygenic inheritance
Syllabus: Paper I > 12. Applications of Anthropology > DNA technology in diseases and medicine
5(b) Prehistoric significance of Rakhigarhi
10 Marks150 words
Syllabus: Paper I > 1.8(b) Cultural Evolution > Harappan sites
Syllabus: Paper I > 8.4 Research Methods > Analysis, interpretation and presentation of data
1(c) Race and Ethnicity
10 Marks150 words
Syllabus: Paper I > 9.5 Race and racism > Race and ethnicity
1(a) Scope and relevance of Social and Cultural Anthropology
10 Marks150 words
Syllabus: Paper I > 1.3 Main branches of Anthropology, their scope and relevance
Syllabus: Paper I > 9.4(a) Numerical and structural aberrations (disorders)
5(e) William Ogburn and Cultural lag
10 Marks150 words
Syllabus: Paper I > 6. Anthropological Theories > Cultural lag (Ogburn)