• How do we explain the fact that animals seem so well adapted to their environment?
• In other words, how did they get body parts and behaviours that are exactly what they need to survive?
Lamarck’s Theory
Called “the inheritance of acquired characters,” included the idea of “use and disuse of parts”.
The more you use a body part, the more it is amplified.
Or, vice versa, use it or lose it…
• Lamarck thought characteristics acquired in an animal’s lifetime (e.g., longer neck of giraffe) could be passed down
• This theory is thus called “the inheritance of acquired characters”
Darwin’s explanation
• Darwin explains adaptation as due to natural selection
• However, he also used Lamarck’s theory!
• Adaptation can refer to the process by which a creature gets its useful parts
• Or it can mean those useful parts themselves
• Darwin’s theory explains adaptation as a result of natural selection
• The theory of natural selection also explains many more facts about the living world.
• But how does natural selection work? (See natural selection section in DTP and natural selection PowerPoint