Evolution and Natural Selection

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Evolution Noun

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[ev-uh-loo-shun]

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Evolution

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The gradual change in the inherited characteristics of a biological population over successive generations.

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Example: A common ancestor finch evolves into different species, each with a unique beak shape adapted to a specific food source like seeds, cacti, or insects.

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Natural Selection Noun

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[nach-er-ul suh-lek-shun]

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Natural Selection

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The process where organisms better adapted to their environment tend to survive and produce more offspring.

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Example: In a population of bacteria, some are naturally resistant to antibiotics. When antibiotics are used, they kill the non-resistant bacteria, allowing the resistant ones to survive and multiply.

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Naturalist Noun

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[nach-er-uh-list]

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Naturalist

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A scientist who studies the natural world and its history, especially focusing on plants and animals.

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Example: A naturalist is a scientist who studies organisms and their environment through direct observation and data collection, as shown by these people in the field.

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Species Noun

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[spee-sheez]

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Species

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A group of living organisms consisting of similar individuals capable of interbreeding to produce fertile offspring.

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Example: Two distinct crow types (Carrion and Hooded) can interbreed to create hybrids, illustrating how the ability to reproduce helps define a species.

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Fossil Noun

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[fos-ul]

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Fossil

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The preserved remains, impression, or trace of a once-living organism from a past geological age.

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Example: This image shows the preserved skeletal remains of an ancient organism embedded in rock, a classic example of a body fossil providing evidence for evolution.

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Adaptation Noun

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[ad-ap-tey-shun]

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Adaptation

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An inherited trait or characteristic that helps an organism survive and reproduce in its specific environment.

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Example: This diagram shows a cactus's adaptations for desert survival, such as its thick waxy skin to reduce water loss and widespread roots to absorb rain.

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Adaptive Radiation Noun

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[uh-dap-tiv rey-dee-ey-shun]

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Adaptive Radiation

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The process by which a single species evolves into several different species to fit a number of diverse habitats.

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Example: From one common ancestor, different species of birds evolved with unique beak shapes to eat specific foods like nectar, insects, or seeds.

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Descent with Modification Noun

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[dih-sent with mod-uh-fi-key-shun]

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Descent with Modification

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The principle that each living species has descended, with changes, from other species over time.

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Example: This diagram shows how finches, descendants of a common ancestor, developed modified beaks adapted to eat specific foods like seeds, insects, or fruit.

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Common Descent Noun

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[kom-un dih-sent]

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Common Descent

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The scientific principle that all living organisms on Earth are descended from a common ancestor or ancestral gene pool.

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Example: This diagram shows that modern humans and chimpanzees evolved from a single, shared 'common ape ancestor' that lived millions of years ago.

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Darwinism Noun

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[dahr-win-iz-um]

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Darwinism

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The theory of the evolution of species by natural selection advanced by Charles Darwin.

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Example: This image shows different beak shapes in related finch species, an adaptation that helps them eat different foods and survive in their environment.