Human Genetics in Anthropology – UPSC Notes for Anthropology Optional

Introduction

Genetics plays a crucial role in the Anthropology Optional UPSC, especially in Paper I (Physical Anthropology). It deals with the study of inheritance, variation, and evolution of human traits. For UPSC aspirants, mastering Human Genetics is essential to score well in Mains and to connect biological concepts with socio-cultural anthropology.

At Vijetha IAS Academy, Delhi, our structured Anthropology Notes for UPSC simplify complex genetic concepts with diagrams, case studies, and examples.

Definition of Genetics

• Genetics: Study of genes and inheritance.
   
• Gene: Fundamental unit of inheritance (term coined by Sulton, 1902).
   
• Genetics term: Coined by Battison, 1906.
   
• Phenotype: External expression of traits (e.g., tall, dwarf).
   
• Genotype: Internal genetic constitution (TT, Tt, tt).
   

Fathers of Genetics

• Gregor Mendel – Father of Genetics (pea plant experiments).
   
• T.H. Morgan – Father of Modern Genetics (animal studies, insects).
   
• Francis Dalton – Father of Human Genetics.
   

Mendelian Genetics

Key Terms

• Homozygous Alleles: TT or tt (same alleles).
   
• Heterozygous Alleles: Tt (different alleles).
   
• Dominant Character: Expressed in both homozygous and heterozygous condition.
   
• Recessive Character: Expressed only in homozygous condition.
   

Monohybrid Cross Example (Height in Pea Plants)

F2 Generation Ratio

• Genotypic: 1 TT : 2 Tt : 1 tt
   
• Phenotypic: 3 Tall : 1 Dwarf
   

Mendelian Genetics in Humans

Chromosomes and Karyotype Analysis

• Chromosomes: Thread-like structures of DNA + proteins in nucleus.
   
• Human Chromosomes: 23 pairs (46 total) – Tjio & Levan, 1956.
   
  • Autosomes: 22 pairs (physical traits).
     
  • Sex Chromosomes: 1 pair (XX female, XY male).
     

Types of Chromosomes

• Metacentric – Centromere in middle (V-shape).
   
• Sub-metacentric – Slightly off-center.
   
• Telocentric – Centromere at one end.
   

Karyotyping

• Arrangement of chromosomes by size, shape, centromere.
   
• Idiogram: Diagrammatic representation.
   

Cytogenetic / Fluorescent Methods

Used for identifying DNA base pairing and chromosomal abnormalities.

Pedigree Analysis

• Definition: Diagrammatic record of inheritance across generations.
   
• Purpose: To study transmission of genetic traits (e.g., haemophilia, colour blindness).
   
• Symbols: Circles (female), Squares (male), Shaded (affected).
   

Usefulness

1. Helps with genetic counselling (disease risk prediction).
    
2. Shows recessive/dominant inheritance patterns.
    
3. Explains the spread of genetic traits (e.g., haemophilia in European royal families).
    
4. Assists in avoiding consanguineous marriages leading to disorders.
    

Twin Studies

• 
  If MZ twins > DZ twins in similarity → Genetic factors stronger.
   
• If similarities are equal → Environmental influence stronger.
   

Conclusion

Human Genetics is a vital component of Anthropology Optional UPSC. By linking Mendelian principles, chromosome analysis, pedigree studies, and twin research, aspirants can strengthen their answers with scientific depth.

At Vijetha IAS Academy, Delhi, we provide Anthropology Notes, Online Coaching, and Test Series that simplify complex genetics into exam-ready content.

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