Darwin’s Tea Party

Biological Adaptation

• 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

Camouflage as a form of adaptationCamouflage as a form of adaptation

Camouflage is an amazing kind of adaptationCamouflage is an amazing kind of adaptation

Spot the crab here?

Spot the stick insect?Spot the stick insect?

The wonderful incheumonidae (type of wasp) that eats caterpillars from the inside out!

Echolocation: another adaptation allowing bats to “see” by sonar or sound waves.

Adaptations can be about behaviour, like the web-making behaviour of the spider

• 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

The End