Selection favouring intermediate phenotypes, as seen in human birth weight.
Extremes are selected against, narrowing variation around the mean. Human birth weight is optimal at about 3 to 4 kg: very small and very large babies have higher mortality.
It maintains well-adapted phenotypes in stable environments.
Selection favouring intermediate phenotypes, as seen in human birth weight.
Stabilising Selection is one of the 53 topics in Evolution. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Disruptive Selection, Natural Selection, Directional Selection.
Clutch size in birds tends toward an optimum.
Work through the Beginner topics in Evolution first, such as Evolution, Natural Selection, Charles Darwin, then return to Stabilising Selection. Intermediate topics assume the Beginner vocabulary.
The closest topics to Stabilising Selection are Disruptive Selection, Natural Selection, Directional Selection, Extinction. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Stabilising Selection. To practise the whole of Evolution, use the Evolution quiz.
Stabilising Selection: Selection favouring intermediate phenotypes, as seen in human birth weight. Disruptive Selection: Selection favouring both extremes over the average, which may lead to divergence. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Disruptive Selection and explain the difference aloud. Finally, take the Evolution quiz and come back to this page for any question you miss.
Selection favouring both extremes over the average, which may lead to divergence.
🦎 EvolutionIndividuals with traits better suited to their environment survive and reproduce more, passing those traits on.
🦎 EvolutionSelection favouring one extreme phenotype, shifting the population mean in one direction.
🦎 EvolutionThe permanent disappearance of a species, occurring naturally and at accelerated rates today.
🦎 Evolution