https://www.khanacademy.org/science/ap-biology/natural-selection/natural-selection-ap/v/introduction-to-evolution-and-natural-selection 2024-05-06T19:22:43.24334365Z Introduction to evolution and natural selection Natural selection is a mechanism of evolution and explains how species adapt to their environment over time through variations in traits. Examples include the peppered moth adapting to industrial pollution, yearly flu virus changes, and antibiotic-resistant bacteria. Understanding natural selection is essential for studying living systems. Sal Khan video https://cdn.kastatic.org/googleusercontent/t55LO6_r6qTqM1BV6MfZo9h5rMzP12VWMnPrKSmkzGH5D2aO2gWmJ6qYIn5haLm4ZhtU9vn_hU6ZNSiUskhxHoU Introduction to evolution and natural selection Natural selection is a mechanism of evolution and explains how species adapt to their environment over time through variations in traits. Examples include the peppered moth adapting to industrial pollution, yearly flu virus changes, and antibiotic-resistant bacteria. Understanding natural selection is essential for studying living systems. https://cdn.kastatic.org/ka-youtube-converted/GcjgWov7mTM.mp4/GcjgWov7mTM.mp4 1059 Mechanisms and theories of evolution https://www.khanacademy.org/science/ap-biology/natural-selection/natural-selection-ap/e/natural-selection 2023-08-07T17:09:37.131449861Z Natural selection Test your knowledge of natural selection! Megan Cohn exercise https://www.khanacademy.org/science/ap-biology/natural-selection/natural-selection-ap/a/darwin-evolution-natural-selection 2024-08-14T09:18:23.232272817Z Darwin, evolution, & natural selection Learn about Charles Darwin's voyage on the HMS Beagle and his ideas about evolution and natural selection. article https://www.khanacademy.org/science/ap-biology/natural-selection/natural-selection-ap/v/natural-selection-and-the-owl-butterfly 2024-05-06T19:22:43.24334365Z Natural selection and the owl butterfly Intricate patterns, such as the owl butterfly's eye-like wing markings, evolve through natural selection. Over thousands of generations, small variations in wing patterns offer slight survival advantages, leading to the dominance of beneficial traits. This gradual process allows complex designs to emerge from random genetic mutations. Sal Khan video https://cdn.kastatic.org/googleusercontent/Czp9jBPie2VXqXEQoGcITuxhutXFaC6v3A2aFvHkntpFzV9wOzUzIkVb6_XVMSQKXQglbWRNWflcx4Jnn14xDlI Natural selection and the owl butterfly Intricate patterns, such as the owl butterfly's eye-like wing markings, evolve through natural selection. Over thousands of generations, small variations in wing patterns offer slight survival advantages, leading to the dominance of beneficial traits. This gradual process allows complex designs to emerge from random genetic mutations. https://cdn.kastatic.org/ka-youtube-converted/dR_BFmDMRaI.mp4/dR_BFmDMRaI.mp4 809 Mechanisms and theories of evolution https://www.khanacademy.org/science/ms-biology/x0c5bb03129646fd6:natural-and-artificial-selection/x0c5bb03129646fd6:natural-selection/e/understand-natural-selection-ms 2025-07-01T21:05:20.470958635Z Understand: natural selection Check your understanding of natural selection in this set of free, standards-aligned practice questions. Megan Cohn exercise https://www.khanacademy.org/science/ap-biology/natural-selection/hardy-weinberg-equilibrium/a/hardy-weinberg-mechanisms-of-evolution 2024-08-14T09:18:23.232272817Z Mechanisms of evolution Learn about Hardy-Weinberg equilibrium and how changes in populations can lead to evolution. article https://www.khanacademy.org/science/ap-biology/natural-selection/natural-selection-ap/v/biodiversity-and-natural-selection-two 2024-05-06T19:22:43.24334365Z Biodiversity and natural selection The patterns and processes of evolution play a crucial role in biodiversity. Natural selection, adaptation, and inheritance serve as key mechanisms driving diversity. Examining relationships among organisms, genealogical trees, and environmental factors provides insight into the complex interplay shaping Earth's rich biodiversity. California Academy of Sciences video https://cdn.kastatic.org/googleusercontent/VGxVT85q8aRF0ctmCtCn61i3P9uZuOzJ7Lhqaki2eBoPOhRLEyMU3OzDzExESHpWRFcUOYHwODBJBJMETFG8QHoA Biodiversity and natural selection The patterns and processes of evolution play a crucial role in biodiversity. Natural selection, adaptation, and inheritance serve as key mechanisms driving diversity. Examining relationships among organisms, genealogical trees, and environmental factors provides insight into the complex interplay shaping Earth's rich biodiversity. https://cdn.kastatic.org/ka-youtube-converted/sNgsCT0E7Es.mp4/sNgsCT0E7Es.mp4 543 Mechanisms and theories of evolution https://www.khanacademy.org/science/hs-bio/x230b3ff252126bb6:mechanisms-of-evolution-hs/x230b3ff252126bb6:mechanisms-of-evolution/e/understand-natural-selection-and-evolution 2025-04-03T18:31:32.704008424Z Understand: natural selection and evolution Check your understanding of natural selection and evolution in this set of free, standards-aligned practice questions. exercise https://www.khanacademy.org/science/ms-biology/x0c5bb03129646fd6:natural-and-artificial-selection/x0c5bb03129646fd6:natural-selection/v/natural-selection-in-peppered-moths 2025-08-26T23:00:40.300039358Z Natural selection in peppered moths The video discusses natural selection, illustrated by the peppered moth's color changes in London. Darker moths became predominant during the Industrial Revolution due to pollution, providing better camouflage against predators. With recent environmental improvements, lighter moths are reemerging. This demonstrates how environmental shifts can influence the prevalence of certain traits in a species over time. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/abaf5df1-f439-45a6-927a-1e9fada8ef8a_1280_720_base.png Natural selection in peppered moths The video discusses natural selection, illustrated by the peppered moth's color changes in London. Darker moths became predominant during the Industrial Revolution due to pollution, providing better camouflage against predators. With recent environmental improvements, lighter moths are reemerging. This demonstrates how environmental shifts can influence the prevalence of certain traits in a species over time. https://cdn.kastatic.org/ka-youtube-converted/y4BHYYBif3Q.mp4/y4BHYYBif3Q.mp4 197 Mechanisms and theories of evolution https://www.khanacademy.org/science/hs-bio/x230b3ff252126bb6:mechanisms-of-evolution-hs/x230b3ff252126bb6:mechanisms-of-evolution/e/understand-natural-selection 2025-03-05T15:21:04.570949227Z Understand: natural selection Check your understanding of natural selection in this set of free, standards-aligned practice questions. exercise https://www.khanacademy.org/science/ap-biology/heredity/chromosomal-inheritance-ap/v/variation-in-a-species 2024-05-06T19:22:43.24334365Z Variation in a species Natural selection relies on genetic variation within a species. Mutations alone aren't sufficient for creating diversity; sexual reproduction plays a crucial role as well. By combining genetic material from two parents, offspring inherit a unique mix of traits, resulting in vast potential for variation. This process allows for more efficient adaptation and survival, making sexual reproduction a widespread biological strategy. Sal Khan video https://cdn.kastatic.org/googleusercontent/iqKf7epfDD2hHDMtAGsPRi9PJWxgCZ_KRXh-Jerb9PGl3qFhv4ZqTxDfQmuDg0HtDJlj_dGwLkl1kbHfBwkm75Q Variation in a species Natural selection relies on genetic variation within a species. Mutations alone aren't sufficient for creating diversity; sexual reproduction plays a crucial role as well. By combining genetic material from two parents, offspring inherit a unique mix of traits, resulting in vast potential for variation. This process allows for more efficient adaptation and survival, making sexual reproduction a widespread biological strategy. https://cdn.kastatic.org/ka-youtube-converted/DuArVnT1i-E.mp4/DuArVnT1i-E.mp4 1191 Mechanisms and theories of evolution https://www.khanacademy.org/science/hs-bio/x230b3ff252126bb6:mechanisms-of-evolution-hs/x230b3ff252126bb6:mechanisms-of-evolution/v/natural-selection-and-evolution 2022-09-24T04:45:13.131282509Z Natural selection and evolution Evolution is a consequence of the interaction of four factors: (1) the potential for a species to increase in number, (2) the genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for an environment’s limited supply of the resources that individuals need in order to survive and reproduce, and (4) the ensuing proliferation of those organisms that are better able to survive and reproduce in that environment. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/3627aa50-5b18-4499-b04a-c5d4fe9d6868_1280_720_base.png Natural selection and evolution Evolution is a consequence of the interaction of four factors: (1) the potential for a species to increase in number, (2) the genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for an environment’s limited supply of the resources that individuals need in order to survive and reproduce, and (4) the ensuing proliferation of those organisms that are better able to survive and reproduce in that environment. https://cdn.kastatic.org/ka-youtube-converted/ifyEocJ2Rog.mp4/ifyEocJ2Rog.mp4 390 Mechanisms and theories of evolution https://www.khanacademy.org/science/ap-biology/cell-structure-and-function/cell-compartmentalization-and-its-origins/v/endosymbiosis-theory 2023-08-07T17:09:37.131449861Z Endosymbiosis theory Certain characteristics of mitochondria and chloroplasts support the endosymbiotic theory, which posits that eukaryotic cells evolved from simpler prokaryotic cells that merged together. Lynn Margulis was a key figure in developing this theory. Margulis's work was at first met with skepticism, but now the endosymbiotic theory is widely accepted in the scientific community. video https://cdn.kastatic.org/googleusercontent/uADRPShfHBL3Igww-z-NC6EubTzoXA1SKdFEurK6bgs90tBdxIZQCo7Ou_-hzWvEzk9EH8owOn7ABU0g3UtWdZKalw Endosymbiosis theory Certain characteristics of mitochondria and chloroplasts support the endosymbiotic theory, which posits that eukaryotic cells evolved from simpler prokaryotic cells that merged together. Lynn Margulis was a key figure in developing this theory. Margulis's work was at first met with skepticism, but now the endosymbiotic theory is widely accepted in the scientific community. https://cdn.kastatic.org/ka-youtube-converted/eCWwKrJyKxA.mp4/eCWwKrJyKxA.mp4 250 Mechanisms and theories of evolution