Evolution vocabulary
Use technical vocabulary for evolution and natural selection — adaptation, evolution, natural selection, extinct, extinction, fossil record, species, common ancestor, mutation, variation — and explain the mechanism of natural selection using these terms in the correct sequence
What a learner can do afterwards
- Use 'adaptation' correctly to describe a feature that helps an organism survive in its environment
- Explain natural selection using 'variation', 'selection pressure', and 'reproduction' correctly in sequence
- Use 'extinct' and 'extinction' correctly and distinguish them from 'endangered'
1 · Read
Every living thing belongs to a species: a group that can breed together, like all giraffes or all housecats. Within a species, individuals are not identical. This is called variation. A giraffe with a slightly longer neck than others in its group is an example of variation. Variation can come from a mutation, a random change in genes passed from parents to young.
When a feature helps an organism survive and reproduce in its environment, we call it an adaptation. A polar bear's thick white fur is an adaptation: it keeps the bear warm and hides it in the snow. Adaptations build up over many generations. If every member of a species dies out, the species is extinct. An endangered species still has a few members left.
Giraffe ancestors had necks of different lengths, and that was variation. When food near the ground grew scarce, that shortage acted as a selection pressure. Giraffes with longer necks could reach higher leaves, so they were more likely to survive and reproduce. Their calves inherited the longer-neck trait. Repeated over many generations, this process is natural selection, and it is one way evolution happens. Fossils in rock show how life changed, and shared bones point to a common ancestor.
If every member of a species dies out, the species is extinct, and that event is called extinction. Don't confuse this with endangered: an endangered species has very few members left, but it has not disappeared yet.
Scientists study the fossil record: traces and remains of past life preserved in rock. It helps them trace species back to a common ancestor, an earlier species that two or more living species evolved from. Evolution is the word for how species change across generations.
Variation creates differences, selection pressure decides who survives and reproduces, and repeated over generations that is evolution, while species that cannot keep up may become extinct.
Rewritten readings were written for this dataset.
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