Biology · Class 12 · Chapter 6
Evolution
13 lessons113 min6 simulations10 practice questions
This chapter tells the long story of life: how the universe, the earth and the first molecules of life arose, how Darwin explained the diversity of living forms by natural selection, and what evidence supports evolution. It then turns to the mechanism (mutation, Hardy-Weinberg equilibrium and the factors that upset it) and closes with a timeline of life forms and the origin of man.
Also called: origin of life · natural selection · Hardy-Weinberg principle
Lessons
13 lessons · 113 min
01Early earth and early ideasNCERT §6.17 min02Chemical evolution and the first lifeNCERT §6.17 min03Special creation and Darwin's theoryNCERT §6.26 min04Fossils and embryos as evidenceNCERT §6.37 min05Homology and analogyNCERT §6.310 min1 sim06Natural selection seen in actionNCERT §6.310 min1 sim07Adaptive radiationNCERT §6.49 min1 sim08Biological evolution and Darwin's reasoningNCERT §6.57 min09Mutation and the Hardy-Weinberg principleNCERT §6.6, §6.710 min1 sim10What disturbs the equilibriumNCERT §6.713 min2 sims11A brief account of evolutionNCERT §6.87 min12Origin and evolution of manNCERT §6.97 min13Chapter reviewMust-know facts, traps and formulas13 min
Simulations
6 in this chapter
One bone plan, four mammal limbsIn: Homology and analogyMoths on a trunk: natural selection in actionIn: Natural selection seen in actionDarwin's finches: one ancestor, many beaksIn: Adaptive radiationHardy-Weinberg: from allele frequency to genotypesIn: Mutation and the Hardy-Weinberg principleThree ways selection reshapes a bell curveIn: What disturbs the equilibriumGenetic drift: allele frequency changing by chanceIn: What disturbs the equilibrium