Human Variation: Race, Racism, Genetics, Somatotyping, and Ethnic Groups

Chapter 4 of the WBCS Anthropology Optional Paper I syllabus focuses on Human Variation. This chapter bridges biological anthropology, population genetics, and socio-cultural critique. Questions from this section are highly structured, factual, and scoring. To score maximum marks, answers should include clear definitions, taxonomic criteria, biometric formulas, genetic mechanisms, and comparative tables.

This note covers the complete WBCS syllabus for Chapter 4:

• 4.1 Concept of Race, racism.
• 4.2 Basis of variation – Morphological (hair, eye), metric (stature, head shape), Polymorphic (genetic marker) – blood group (ABO, Rh), Hb, PGM, HP, Y-chromosome STR, mtDNA.
• 4.3 Concept of Human physique and somatotype.
• 4.4 Concept of ethnic groups – Mongoloid, Caucasoid, Negroid, Australoid.

How to Use This Note in WBCS Mains

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Ready-made opening line:
Human variation refers to the range of biological, morphological, genetic, and physiological differences observed within and between human populations, shaped by the complex interplay of evolutionary forces (mutation, selection, drift, flow) and environmental adaptations.

Ready-made conclusion:
Thus, the study of human variation has evolved from arbitrary, typological racial classifications of the colonial era to a dynamic, clinal, and genetic understanding of human diversity, highlighting the fundamental biological unity of modern Homo sapiens.

4.1 Concept of Race and Racism

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1. Concept of Race (The Biological vs. Typological View)

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In modern biological anthropology, Race is defined as a geographically circumscribed population division of a species, which differs in the frequencies of some gene variants (alleles) from other divisions of the same species.

Historically, anthropologists viewed race as static, fixed “types” (typological concept). Today, it is understood as a dynamic, open genetic system with continuous, overlapping variation (clinal distribution).

Classic Definitions

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Earnest Hooton (1946)
“A race is a physical division of mankind, the members of which are distinguished by the possession of a combination of physical (anatomical) features, characterized by common descent.”

Ashley Montagu (1942)
Montagu strongly opposed the biological reality of race, famously calling it “Man’s Most Dangerous Myth,” and suggested replacing the biological term “race” with “ethnic group” to emphasize cultural and historical factors over rigid biological determinism.

UNESCO Statements on Race

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Following World War II, UNESCO organized panels of scientists to counter the rise of scientific racism.

• 1950 & 1951 Declarations: Asserted that “race” is a social myth rather than a biological phenomenon, and that all human beings belong to the same species, Homo sapiens.
• 1964 (Moscow) & 1967 Declarations: Emphasized that biological differences do not justify social inequality or intellectual hierarchy.
• 1995 (Declaration on Race and Racial Prejudice): Confirmed that genetic diversity does not support any classification of races as “superior” or “inferior.”

2. Racism

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Racism is an ideological belief system asserting that physical biological traits determine psychological, behavioral, and intellectual capacities, thereby classifying certain populations as inherently superior or inferior.

Biological Determinism (Linking genes to behavior) ──> Prejudice & Bias ──> Institutional Discrimination (Racism)

Key Dimensions of Racism:

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1. Scientific Racism (Historical): The misuse of pseudoscientific techniques (e.g., craniometry in the 19th century by Samuel Morton) to justify slavery, colonialism, and eugenic policies.
2. Eugenics: The socio-political movement aiming to “improve” the genetic quality of a human population (often through forced sterilization and selective breeding), famously misused during the Nazi regime.
3. Sociological Impact: The conversion of arbitrary biological markers (like skin color) into rigid social hierarchies, leading to systemic inequality.

4.2 Basis of Variation

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Human biological variation is classified into three categories: Morphological (observed visually), Metric (measured quantitatively), and Polymorphic (genetically determined at the molecular/biochemical level).

                      ┌───────────────────────────┐
                      │    HUMAN VARIATION        │
                      └─────────────┬─────────────┘
                                    │
         ┌──────────────────────────┼──────────────────────────┐
         ▼                          ▼                          ▼
  [MORPHOLOGICAL]                [METRIC]                [POLYMORPHIC]
  (Visual Traits)           (Quantitative Measures)     (Genetic Markers)
  - Hair Form & Color       - Stature                   - Blood Groups (ABO, Rh)
  - Eye Color & Fold        - Cephalic Index            - Hb, PGM, HP, mtDNA, Y-STR

I. Morphological Basis of Variation (Somatoscopic Traits)

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1. Hair

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Hair is one of the most visible somatoscopic markers of human diversity. It is studied based on four criteria:

• Hair Form: Classified into three primary categories:
  1. Lissotrichous (Straight): Coarse, round in cross-section. Characteristic of Mongoloid populations.
  2. Cymotrichous (Wavy/Curly): Oval in cross-section. Common in Caucasoid populations.
  3. Ulotrichous (Woolly/Frizzy): Flat, kidney-shaped in cross-section. Characteristic of Negroid populations.
• Hair Color: Controlled by the relative amount and type of melanin:
  • Eumelanin: Provides black and brown pigments.
  • Pheomelanin: Provides red and blonde pigments.
• Hair Texture: Classified into fine, medium, and coarse.

2. Eye

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Eye variation is characterized by pigmentation and structural folds.

• Eye Color (Iris Pigmentation):
  • Controlled by melanin density in the stroma of the iris.
  • Low melanin results in blue or green eyes (common in Northern European Caucasoids); high melanin results in dark brown or black eyes (universal in Negroids, Mongoloids, and Australoids).
• Epicanthic Fold (Mongolian Fold):
  • A skin fold of the upper eyelid that covers the inner corner (medial canthus) of the eye.
  • It serves as an adaptation to protect the eyes from extreme cold and wind-blown snow in East Asia. It is a hallmark morphological marker of Mongoloid populations.

II. Metric Basis of Variation (Quantitative Traits)

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1. Stature

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Stature (height) is a polygenic quantitative trait influenced by genetic inheritance and environmental factors (nutrition, disease, climate).

• Martin’s Classification of Stature:
  • Pygmy / Very Short: $< 150 \text{ cm}$
  • Short: $150.0 - 159.9 \text{ cm}$
  • Medium: $160.0 - 169.9 \text{ cm}$
  • Tall: $170.0 - 179.9 \text{ cm}$
  • Very Tall: $\ge 180 \text{ cm}$
• Ecogeographical Rules:
  • Allen’s Rule: In colder climates, limbs are shorter to minimize heat loss; in warm climates, limbs are longer to maximize heat loss.

2. Head Shape (Cephalic Index)

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Developed by Swedish anatomist Anders Retzius (1842), the Cephalic Index (CI) is a key metric marker used to classify human head shapes in physical anthropology.

• Standard Classification:
  1. Dolichocephalic (Long-headed): $\text{CI} \le 75.9$. Common in Negroids, Australoids, and Nordic Caucasoids.
  2. Mesocephalic (Medium-headed): $\text{CI} \text{ between } 76.0 \text{ and } 80.9$. Broadly distributed across intermediate groups.
  3. Brachycephalic (Broad-headed / Round-headed): $\text{CI} \ge 81.0$. Characteristic of Mongoloid populations and Alpine Caucasoids.

III. Polymorphic Basis of Variation (Genetic & Molecular Markers)

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Genetic polymorphisms occur when a gene has two or more alleles in a population, each with a frequency of at least $1\%$. These markers are unaffected by environmental factors, making them highly reliable for studying human variation and evolutionary history.

1. Blood Group Systems

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• ABO Blood Group:
  • Discovered by Karl Landsteiner (1900).
  • Governed by tri-allelic inheritance ($I^A$, $I^B$, $I^O$) on Chromosome 9.
  • Anthropological Significance: The $I^B$ allele exhibits a geographical gradient (cline), peaking in Central Asia/Northern India and declining toward Western Europe. The $I^O$ allele is highly frequent in Native American populations.
• Rh Blood Group System:
  • Discovered by Landsteiner and Wiener (1940).
  • Controlled by the presence (Rh+) or absence (Rh-) of the D antigen.
  • Anthropological Significance: Rh-negative alleles ($dd$ genotype) are highly frequent in Basque populations of Europe ($30-35\%$) but are virtually absent in Native American and East Asian populations.

2. Hemoglobin (Hb) Polymorphism

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Hemoglobin contains four polypeptide chains. Point mutations in the genes coding for these chains create variants of anthropological and medical significance.

• Normal Hb (HbA): The standard adult hemoglobin ($\alpha_2\beta_2$).
• Sickle Cell Hemoglobin (HbS):
  • Caused by a single point mutation in the $\beta$-globin gene on Chromosome 11 (substitution of glutamic acid by valine at position 6).
  • Malaria Hypothesis (Balancing Selection): Homozygotes ($Hb^S Hb^S$) suffer from severe sickle cell anemia, while heterozygotes ($Hb^A Hb^S$) are highly resistant to Plasmodium falciparum malaria. This “heterozygote advantage” maintains the $Hb^S$ allele at high frequencies in malaria-endemic regions (Sub-Saharan Africa, Central India).
• Other Hb Variants: HbC, HbE (common in Southeast Asia), and Thalassemia (under-production of globin chains).

3. Enzyme Polymorphisms

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• PGM (Phosphoglucomutase):
  • A metabolic enzyme that catalyzes the interconversion of glucose-1-phosphate and glucose-6-phosphate.
  • It exhibits genetic variation at three independent loci ($PGM_1, PGM_2, PGM_3$), offering distinct allele frequencies across ethnic groups.
• HP (Haptoglobin):
  • A plasma protein synthesized in the liver that binds free hemoglobin to prevent kidney damage.
  • Controlled by two main codominant alleles ($HP^1$ and $HP^2$).
  • Anthropological Significance: The $HP^1$ allele frequency is high in parts of South America and Africa ($0.60 - 0.80$) but significantly lower in India and East Asia ($0.10 - 0.20$).

4. Uniparental Genetic Markers

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Y-Chromosome STR (Short Tandem Repeats)

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• Mode of Inheritance: Paternal inheritance (passed strictly from father to son via the Y-chromosome).
• Properties: The Non-Recombining region of the Y-chromosome (NRY) does not undergo crossing over, preserving the paternal genetic history.
• Anthropological Application: Useful for tracing male migrations, reconstructing paternal genealogies, patrilocality studies, and forensic paternity testing.

mtDNA (Mitochondrial DNA)

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• Mode of Inheritance: Maternal inheritance (passed strictly from mother to offspring via the egg cell).
• Properties: Possesses a high mutation rate, small size (approx. 16,569 base pairs), and lacks genetic recombination.
• Anthropological Application: Tracing maternal lineages, calculating the time of common maternal ancestry (“Mitochondrial Eve” dating back to ~200,000 years in Africa), and mapping out early human migratory routes across continents.

4.3 Concept of Human Physique and Somatotype

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Physique refers to the general anatomical configuration of the human body. Somatotyping is the systematic categorization of the human body build based on its physical characteristics.

1. Historical Systems of Classification

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• Hippocrates & Galen: Classified individuals into Humoral types (Sanguine, Phlegmatic, Choleric, Melancholic).
• Ernst Kretschmer (1921): Linked body types with psychiatric predispositions:
  1. Pyknic: Round, fat (associated with manic-depressive disorder).
  2. Athletic: Muscular, broad-shouldered (associated with schizophrenia).
  3. Asthenic (Leptosomic): Thin, tall, frail (associated with schizophrenia).
  4. Dysplastic: Asymmetrical, abnormal body proportions.

2. Sheldon’s Method of Somatotyping (1940)

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William H. Sheldon introduced a quantitative classification system based on three embryonic germ layers.

       ┌─────────────────────────────────────────────────────────┐
       │             SHELDON'S SOMATOTYPE COMPONENTS             │
       └──────────────────────────────────┬──────────────────────┘
                                          │
         ┌────────────────────────────────┼──────────────────────────────┐
         ▼                                ▼                              ▼
   [ENDOMORPHY]                     [MESOMORPHY]                   [ECTOMORPHY]
(Endoderm: Digestive)          (Mesoderm: Muscle/Bone)         (Ectoderm: Skin/Nerves)
- Roundness, softness          - Muscularity, skeletal strength- Thinness, delicacy
- Focus: Abdomen, fat          - Focus: Shoulders, chest       - Focus: Linear limbs

• Rating Scale: Each component is rated on a scale of 1 to 7 (1 = minimum development, 7 = maximum development).
• Somatotype Notation: Represented as a three-digit formula: (Endomorphy - Mesomorphy - Ectomorphy).
  • Extreme Endomorph (7-1-1): Dominant body fat, round, soft.
  • Extreme Mesomorph (1-7-1): Dominant muscle and bone, rugged, athletic.
  • Extreme Ectomorph (1-1-7): Dominant linearity, fragile, tall, thin.
  • Balanced/Average (4-4-4): Equal distribution of all three components.
• Limitations of Sheldon’s Method:
  • Subjective (relies heavily on visual evaluation of photos).
  • Static (Sheldon believed somatotypes are genetically fixed and cannot change with diet or exercise).
  • Closed scale (capped strictly at 7).

3. Heath-Carter Method of Somatotyping (1967)

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Developed by Barbara Heath and J.E. Lindsay Carter, this is the most widely accepted somatotyping method in modern anthropology and sports science.

• Key Modifications:
  1. Objective Measurement: Replaces subjective photography with precise anthropometric measurements (weight, height, skinfolds, bone diameters, muscle circumferences).
  2. Open-Ended Scale: Ratings start at 0.5 and can go beyond 7 (e.g., to 9 or 12) to accommodate extreme body builders or highly obese individuals.
  3. Dynamic: Recognizes that a person’s somatotype can change over time due to training, aging, nutrition, and lifestyle.

The Three Components in Heath-Carter:

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1. Endomorphy: Relative fatness (measured via skinfolds at the triceps, subscapular, and supraspinal sites).
2. Mesomorphy: Relative musculoskeletal development (measured via humerus and femur bone breadths, and flexed arm and calf girths corrected for skinfold thickness).
3. Ectomorphy: Relative linearity (derived from height-weight ratio or Ponderal Index: $\text{Height} / \sqrt[3]{\text{Weight}}$).

• Anthropological Significance: Used to evaluate biological adaptations to high-altitude or arctic environments, monitor children’s growth and development, and optimize athletic selection.

4.4 Concept of Ethnic Groups

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Due to the historical misuse and scientific inaccuracies associated with the term “race,” modern anthropologists prefer the term Ethnic Group.

An ethnic group is a social group of people who identify with each other based on shared ancestral, social, cultural, or national experiences. From a biological perspective, “ethnic groups” refer to breeding populations that share distinct gene pools while remaining genetically open to exchange.

Major Classical Ethnic Groups of the World

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Traditionally, humanity was classified into four primary physical groupings: Mongoloid, Caucasoid, Negroid, and Australoid.

                              ┌──────────────────────────┐
                              │  CLASSICAL ETHNIC GROUPS │
                              └─────────────┬────────────┘
                                            │
         ┌──────────────────────────┬───────┴──────────┬──────────────────────────┐
         ▼                          ▼                  ▼                          ▼
    [MONGOLOID]                [CAUCASOID]          [NEGROID]               [AUSTRALOID]
   (Yellow/Brown)             (Fair/Olive)        (Dark/Black)             (Dark/Wavy Hair)
   - Straight Hair            - Wavy Hair         - Woolly Hair            - Wavy Hair
   - Epicanthic Fold          - Narrow Nose       - Prognathism            - Heavy Brow Ridges
   - Brachycephalic           - Dolichocephalic   - Dolichocephalic        - Dolichocephalic

1. Mongoloid

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• Geographical Distribution: East Asia, Southeast Asia, Arctic regions (Inuits), and the Americas (Native Americans).
• Key Biological Characteristics:

2. Caucasoid

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• Geographical Distribution: Europe, North Africa, the Middle East, Central Asia, and Northern South Asia (India).
• Key Biological Characteristics:

3. Negroid

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• Geographical Distribution: Sub-Saharan Africa and historical diaspora populations in the Americas.
• Key Biological Characteristics:

4. Australoid

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• Geographical Distribution: Indigenous populations of Australia (Aborigines), Melanesia, and relict tribal populations in South Asia (e.g., Veddas of Sri Lanka, Kadars of South India).
• Key Biological Characteristics:

WBCS Mains Answer Writing: Previous Years & Practice Questions

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WBCS Mains Anthropology Paper I frequently tests concepts of human variation, race vs. ethnic groups, genetic polymorphism, and somatotyping. Below are standard questions structured according to WBCS marks patterns, along with strategic answering tips.

1. Long Answer Questions (20 Marks)

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• Q1. Define “Race” from a biological perspective. Discuss the biological basis of human variation with special reference to genetic polymorphisms.
  • Mains Strategy: Start with Hooton’s biological definition and UNESCO’s statements. Divide the body of your answer into Morphological, Metric, and Polymorphic (Genetic) bases. Spend significant space explaining ABO, Rh, and Hemoglobin (HbS heterozygote advantage) polymorphisms as genetic markers.
• Q2. Critically analyze the concept of “Somatotyping.” Compare the Sheldon and Heath-Carter methods of somatotyping, highlighting their biological and anthropological significance.
  • Mains Strategy: Define somatotyping and its evolutionary context. Detail Sheldon’s three germ-layer components (1-7 scale) and illustrate the somato-chart. Then, detail the Heath-Carter modifications (objective anthropometry, open scale, dynamic nature). Use a comparative table to highlight differences.

2. Medium Answer Questions (10 to 15 Marks)

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• Q3. Distinguish between the concepts of “Race” and “Ethnic Group.” Why do modern anthropologists prefer the latter?
  • Mains Strategy: Use a comparative table (Biological vs. Socio-cultural/Open genetic systems). Quote Ashley Montagu (“Man’s Most Dangerous Myth”) and highlight the UNESCO 1950/1951 findings to explain the transition.
• Q4. Discuss the physical characteristics and geographical distribution of Mongoloid and Negroid ethnic groups.
  • Mains Strategy: Dedicate separate subsections for each. For Mongoloids, highlight straight hair (Lissotrichous), epicanthic fold, and brachycephaly. For Negroids, highlight woolly hair (Ulotrichous), prognathism, and dolichocephaly. Include a tabular summary of physical traits.

3. Short Notes (5 Marks)

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• Q5. Write short notes on:
  • (a) Epicanthic Fold: Explain its anatomy, occurrence (Mongoloid), and adaptive significance (protection against cold/glare).
  • (b) Cephalic Index: Define it, state Retzius’ formula, classify head shapes (Dolicho, Meso, Brachy), and mention geographical distributions.
  • (c) Mitochondrial DNA (mtDNA) in Human Ancestry: Highlight maternal uniparental inheritance, lack of recombination, high mutation rate, and its use in tracing migration and dating “Mitochondrial Eve.”
  • (d) Racism and Scientific Racism: Define racism as an ideology, explain the historical roots of scientific racism (eugenics, craniometry), and summarize its modern biological refutation.