Natural Selection & Evolution
Aligned to MS-LS4 — Next Generation Science Standards.
What this lesson teaches
Individuals vary; those with traits better suited to their environment survive and reproduce more, passing those traits on. Over many generations, populations change — this is natural selection.
Worked example
In a dark forest, dark moths are better camouflaged from birds than light moths, so they survive more, and over generations the population becomes mostly dark.
Practice questions
- Explain how a helpful trait becomes more common over generations.
- What role does variation play in natural selection?
- Predict how a fast-running predator affects a prey population's traits.
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Selección Natural y Evolución
Los individuos varían entre sí; aquellos con características mejor adaptadas a su entorno sobreviven y se reproducen más, transmitiendo esos rasgos. A lo largo de muchas generaciones, las poblaciones cambian — esto es la selección natural.
Ejemplo: En un bosque oscuro, las polillas de color oscuro están mejor camufladas de las aves que las polillas claras, por lo que sobreviven más, y con el tiempo la población se vuelve mayormente oscura.
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