Evolution Change Over Time

Your Turn Look at the picture and create your own definition of evolution

EVOLUTION: The diversity among living organisms is a result of evolution If organisms do not evolve they will become extinct

Theories of Evolution - Lamarck Jean Baptiste de Lamarck (1744-1829)

Theories of Evolution – Lamark Believed that species have changed over time for the purpose of adaptation Use and disuse Structures grew or shrank based on how much they were used Transmission of acquired traits Parents could transmit the characteristics acquired through use and disuse directly to their offspring

Your Turn Based on Lamarck’s theory describe why the giraffes had long or short necks and how that affected their offspring.

Your Turn Weisman Experiment: He bred 2 mice who’s tails he had cut. The offspring all had long tails. DOES THIS EXPERIMENT SUPPORT LAMARCK’S THEORY? EXPLAIN.

Theories of Evolution - Lamarck Lamarck’s theory was proven to be incorrect Weisman’s rat experiment

Theories of Evolution - Darwin Charles Darwin (1809-1882)

Theories of Evolution - Darwin Newer forms appearing in the fossil record are the modified descendants of older species ALL species descended from one or a few original types of life Evolution occurs as a result of natural selection

Theories of Evolution - Darwin Individuals with favorable adaptations or traits would survive and reproduce more successfully than individuals without these favorable traits Survival of the fittest Does not mean strength

Your Turn Look at the following cartoons. Pick one and create your own definition of survival of the fittest and natural selection

Darwin developed his theory while working as a naturalist on the HMS Beagle (1831)… Darwin noticed: Variations existed among individuals in a species Individuals will compete for resources like food and space Competition would lead to the death of some individuals while others would survive Individuals that had the favorable variations were more likely to survive and reproduce Darwin’s finches

Industrial Melanism The adaptation of a population by the darkening of its individuals in response to industrial pollution. An example of human impact on Natural Selection. Peppered Moths (Biston betularia) in Manchester England from 1845 to 1890 (industrial revolution). Before industrial revolution trees covered with lichens (light grey color) During industrial revolution trees covered with soot How could this affect the Peppered Moth?

Before Industrial Revolution How many moths do you see? Who is better adapted to the environment? Why?

During Industrial Revolution Now how many moths do you see? Who is better adapted to the environment? Why?