Human Evolution — Part 2: Lamarck and Darwin: visual lesson, ICSE Class 10 Biology (Science Paper 3)

Lesson

How Does Evolution Happen?

Part 2 — two famous explanations, and the moth that showed natural selection at work.

In this lesson you will

Explain Lamarck's theory using the giraffe's neck and human vestigial organs, and state one criticism
Explain the main points of Darwin's theory of natural selection
Explain the change in peppered moth populations during industrialisation

Concept

Lamarck's theory

Table of Lamarck's two main ideas
Idea	Meaning
Use and disuse	Organs used often grow larger; organs not used shrink
Inheritance of acquired characters	Changes gained during life are passed to the young

Diagram

The giraffe's neck: two explanations

Lamarck: stretching lengthened the neck, and the longer neck was inherited. Darwin: necks varied; long-necked giraffes got more food, survived and bred.

Cookies