EY covers ecology, evolution, quantitative ecology, behavioural ecology and applied ecology and evolution. Mathematics appears within the subject syllabus even though there is no separately allotted Engineering Mathematics section.

Ecology and Evolution is tested within a 100-mark paper. The paper also includes General Aptitude. The sections below show the complete subject syllabus.

GATE EY Syllabus and Marks Distribution

There is no optional subject block in this paper. All listed sections are part of the syllabus.

Ecology and Evolution Unit-wise Syllabus

Ecology

• Fundamental Concepts : Abiotic and biotic components of ecosystems; Levels of biological organization (individuals, population, species, community, ecosystems, biomes); Niches; Habitats; Functional traits; Ecophysiology (e.g. physiological adaptations, homeostasis, acclimation).
• Population Ecology : Population dynamics and growth (density dependent/independent); Meta-population ecology; Age-structured populations.
• Interactions: Types of interactions (mutualism, symbiosis, commensalism, competition, parasitism, predation, etc.); Two species population models (Lotka -Voltera equations); Trophic levels and their direct and indirect interactions.
• Community Ecolog y: Community assembly, structure and succession; Role of dispersal and habitat/environmental filtering; levels of diversity (alpha, beta, gamma); Species richness, Evenness and diversity indices; Relative abundance; Species-area relationships; Diversity gradients (e.g. latitudinal and altitudinal gradients); Theory of island biogeography.
• Ecosystem Structure and Function: Primary and secondary productivity; Food web, energy flow, and biogeochemical cycles (e.g. carbon and nitrogen); Ecosystem properties (e.g. stability, resilience); Global biomes and biogeographic zones; Flora and fauna of India; Biogeography of India.

Evolution

• Fundamentals: Lamarckism; Darwinism; Modern Synthesis; Variation; Heritability; Natural selection; Fitness and adaptation; Types of selection (e.g. stabilizing, directional, disruptive).
• Diversity of Life: Origin and history of life on earth; Paleobiological evidence; Diversity and classification of life; Classical taxonomy vs systematics (cladistics).
• Life History Theory : Allocation of resources; Tradeoffs; r/K selection; Strategies (e.g. semelparity and iteroparity).
• Interactions: Co-evolution (e.g. mutualism, arms race, co-speciation); Prey-predator interactions (e.g. mimicry, crypsis); Host-parasite interactions
• Population and Quantitative Genetics : Origins of genetic variation; Mendelian genetics; Hardy -Weinberg equilibrium; Drift; Selection (one-locus two-alleles model); Population genetic structure (panmixia, gene flow, FST); Polygenic traits; Gene-environment interactions (phenotypic plasticity); Heritability; Epistasis and epigenetic inheritance.
• Molecular Evolution and Phylogenetics: Mutation rates; Molecular clocks; Neutral processes; Rates of evolution; Chromosomal and genome evolution (e.g. hybridization, ploidy, introgression); Phylogenetic methods (parsimony; maximum likelihood, Bayesian, etc); Phylogeography
• Macroevolution: Species concepts; Speciation and extinction; Adaptive radiation; Convergence; Biogeographic processes; Continental drift.

Mathematics and Quantitative Ecology

• Mathematics and Statistics in Ecology : Simple functions (linear, quadratic, exponential, logarithmic, etc); Concept of derivatives and slope of a function; Permutations and combinations; Basic probability (probability of
• random events; Sequences of events, conditional probability, etc); Probability distributions (e.g. binomial, normal, Poisson); Descriptive statistics (mean, variance, coefficient of variation, confidence intervals, etc.).
• Study design and Statistical methods: Statistical hypothesis testing; Concept of p-value; Type I and Type II error, Statistical tests (e.g. t- test, Chi-square test); Correlation, linear regression and ANOVA.

Behavioural Ecology

• Classical Ethology and Sensory Ecology: Proximate and ultimate explanations for behaviour; Innate and learnt behavior; Basic mechanisms (e.g., neuroethology, behavioural endocrinology); Modes of communication (chemical, visual, etc); Movement (e.g. navigation).
• Foraging and Reproduction: Optimal foraging theory; Space use (e.g. territoriality); Mating systems; Sexual selection and sexual conflict (runaway selection, good-genes, handicap principle, etc); Parental care.
• Social Behaviour: Costs and benefits of group-living; Intraspecific competition (e.g. scramble and contest); Kin selection; Altruism.

Applied Ecology & Evolution

• Biodiversity and Conservation: Biodiversity-ecosystem function relationships; Ecosystem services; Conservation (endemism, biodiversity hotspots, protected areas); Global conservation initiatives (e.g. COP, IUCN, CBD, CITES); Conservation genetics and methods (genetic diversity, inbreeding depression, DNA fingerprinting and DNA barcoding).
• Disease Ecology and Evolution: Epidemiology; Zoonotic diseases; Antibiotic resistance.
• Global Change: Causes, consequences, adaptation and mitigation of climate change; Threats to biodiversity (e.g. pollution, habitat loss and change); Invasive species.

General Aptitude Syllabus

General Aptitude contributes 15 marks within the 100-mark paper. It is not an additional paper that can be left out when choosing the technical sections.

Chapter-wise Weightage and Important Topics

Only the section-wise marks are fixed. IIT Madras has not assigned a guaranteed number of marks to each chapter of Ecology and Evolution. A topic may appear in one year and receive fewer questions in another; a past-paper count is not an official 2027 weightage.

For a chapter-weightage comparison, record the year, paper code, session, question number and marks of each matching question. Keep a combined question under one main topic or label the overlap explicitly; counting it twice inflates the total. GATE previous-year question papers can be used for this topic-by-topic practice.

Question Types and Negative Marking

The paper uses one-mark and two-mark questions. The number of MCQ, MSQ and NAT questions is not a fixed chapter-wise quota. In an MSQ, selecting one correct option is not enough when the correct answer contains two options.