Population Genetics (Natural selection & Genetic Drift) | Evolution | CSIR Dec 2026 | Lec 3 | IFAS

Population Genetics (Natural selection & Genetic drift) explained with clear concepts and exam-focused approach. Master Population Genetics, Natural Selection, and Genetic Drift for CSIR NET Life Science, GATE & DBT. Covers key concepts, PYQs, problem-solving tricks, and allele frequency calculations. Perfect for aspirants aiming to crack CSIR Dec 2026 with high scores. 🔥 Join India's Best Life Science Coaching - IFAS Online! 🔥 Live Online Batch: Super Emotion Batch 7.7 - Starts on 8 June 2026 🔥 Recorded Online Batch: Revolution Batch 7.7 from Live Batch Completed on 16 May 2026 🔥 New Crash Course for CSIR NET July 2026 Starts on Starts on 8 June 2026 ━━━━━━━━━━━━━━━━━━━━━━━━━ ⏳ Lecture Timeline: [00:00:00] – Introduction of Population Genetics [00:03:31] – Concept: Dirac (Bra-Ket) Notation [00:05:00] – Ket Vector: Column Matrix [00:09:07] – Bra Vector: Complex Conjugate [00:10:42] – Inner Product: Probability Amplitude [00:12:48] – Orthogonal States: Inner Product = 0 [00:14:10] – Orthonormal States: Inner Product = 1 [00:16:37] – Operators in Bra-Ket Notation [00:18:36] – Expectation Value Formula [00:20:40] – Properties: Linearity & Associativity [00:22:16] – Probability in Quantum Mechanics [00:23:45] – Probability from Wavefunction: ∫|ψ|² [00:24:22] – Important: Total Probability = 1 [00:26:23] – Normalization of Wavefunction [00:28:35] – Example: Unnormalised e^{-ax²} [00:30:27] – Trick: Finding Normalisation Constant [00:31:57] – Normalised Wavefunction: (2a/π)^{1/4} e^{-ax²} [00:33:10] – Checking Normalisation: e^{ix} Example [00:33:51] – Superposition States: Normalisation [00:36:20] – Key Condition: Σ|Cₙ|² = 1 [00:37:12] – Example: ψ = ψ₁ + i/2 ψ₂ (Unnormalised) [00:39:29] – Normalising Superposition: Find Constant [00:40:45] – Normalised ψ = √(2/3) ψ₁ + i/√3 ψ₂ [00:41:16] – Summary: Always Check Normalisation [00:42:09] – Next Lecture: Expectation Values [00:42:35] – Complete Session (Population Genetics ) ━━━━━━━━━━━━━━━━━━━━━━━━━ 📖 Topics Covered in This Lecture: • Modern Evolutionary Biology vs Darwinian Concepts • Microevolution & Macroevolution • Forces of Evolution (Natural Selection, Genetic Drift, Gene Flow) • Hardy–Weinberg Principle & Assumptions • Allele & Genotype Frequency Calculation PYQs • Population Genetics Problem-Solving Tricks ━━━━━━━━━━━━━━━━━━━━━━━━━ 📚 Lecture Summary: In this session, IFAS Expert Faculty focuses on Population Genetics, covering natural selection, genetic drift, mutation, gene flow, and non-random mating. The lecture explains microevolution vs macroevolution, Hardy–Weinberg equilibrium, allele/genotype frequency formulas, and how to detect evolving vs non-evolving populations. You’ll learn problem-solving approaches for CSIR NET PYQs and tricks to quickly calculate frequencies. Population Genetics is broken down with relatable examples, ensuring conceptual clarity and exam readiness. ━━━━━━━━━━━━━━━━━━━━━━━━━ 🎯 Why IFAS is India's No. 1 Choice? (Our Results Speak): We have consistently produced Top Rankers in CSIR NET Life Sciaences. 🏆 CSIR NET Dec 2025: 4500+ Selections (AIR 3, 8, 9, 9, ...) 🏆 CSIR NET June 2025: 4100+ Selections (AIR 1, 2, 6, ...) 🏆 CSIR NET Dec 2024: 3000+ Selections (AIR 5, 6, 7, 8...) 🏆 CSIR NET June 2024: 2000+ Selections (AIR 3, 10, 13...) 🏆 CSIR NET Dec 2023: 1200+ Selections (AIR 2, 4, 5...) 📄 View Detailed Result Sheet: 📌 https://drive.google.com/file/d/1THh6... 🎯 Target Audience: This video is highly beneficial for students preparing for: 🚀 CSIR NET Life Science (June 2026) 🚀 GATE Biotechnology (BT) & Life Sciences (XL) 🚀 DBT JRF 🚀 MH SET, WB SET, K SET, & other State Eligibility Tests 🚀 M.Sc. & Ph.D. Entrance Exams 🔗 Important Links: 🌍 Visit our Website: https://ifasonline.com/csir-net/life-... 📞 Contact for Queries: 9172266888 📲 WhatsApp: https://api.whatsapp.com/send?phone=9... 🔥 Qualification Prediction (Free Tool): https://ifasonline.com/QualificationP... 📘 Get Detailed Free Counseling: https://ifasonline.com/csir-net/life-... 📲 Download IFAS App: 📌 Android: https://play.google.com/store/apps/de... 📌 Ios: https://apps.apple.com/us/app/ifas/id... 📘 Buy CSIR NET Life Science Books: 📌 https://ifasonline.com/csir-net/life-... 🔥 Our Social Media Platforms: 📌 Telegram: https://t.me/NET_GATE_SET_LifeScience... 📌 Instagram:   / csir_net_life_science_ifas   📌 Facebook:   / ifasls   📌 WhatsApp: https://api.whatsapp.com/send?phone=9... 💡 Stay Updated, Stay Ahead! This video has following search items #populationgenetics #naturalselection #geneticdrift #csirnetlifescience #microevolution #macroevolution #hardyweinberg #allelefrequency #genotypefrequency #csirdec2026