Evolution (video) | Khan Academy
Evolution is the process where heritable traits in a group of organisms change over many generations. This process is made possible by genetic variation. This variation, often resulting from sexual reproduction, leads to a range of traits within a population. Over time, small differences between organisms in a population can accumulate, leading to the evolution of new species.
En bref

Ajouté le
17 mars 2026
Matière et domaine
life-health · evolution-natural-selection
Niveaux scolaires
6e année–12e année (Terminale)
Type de page
Video
Introduction
Summary of Discussion: Evolution and Related Topics
- Evolutionary Mechanisms:
- Evolution describes how life changes over time, but it does not explain the origin of the first life.
- Asexual reproduction can drive evolution through mutations that occur during mitosis, even without the recombination found in sexual reproduction.
- Genetic traits (such as fingerprints) are unique to individuals, illustrating how specific variations persist within populations.
- Biological and Psychological Concepts:
- Emotions are a fundamental human trait rooted in brain function and biology; "emotional numbness" is distinct from a total lack of emotional capacity.
- Cosmology and Earth Science:
- Big Bounce Theory: A hypothesis suggesting the universe undergoes cycles of expansion (Big Bang) and collapse (Big Crunch).
- Earth Formation: The planet formed through the accretion of debris around the sun via gravity.
- Species and Adaptation:
- Many modern species (including insects, sharks, and various plants) are descendants of organisms that lived during the age of dinosaurs.
- Adaptation allows species to survive environmental changes, leading to the diversification of plant and animal varieties over time.
- There is an approximate 166:1 ratio of flying bird species to flightless bird species.
Avis de la communauté
Pas encore d’avis publiés. Soyez le premier à partager votre expérience.