Natural Selection How evolution works By: Jenny Kong

Smart Start  Write down a description of a physical characteristic of an animal (or plant) that helps it to survive in its environment.

What do you think of adaptation? Three friends were arguing about what would happen if a population of rabbits from a warm, southern climate were moved to a cold, northern climate. This is what they said: Bernie – “I think all of the rabbits will try to adapt to the change.” Leo – “I think most of the rabbits will try to adapt to the change.” Phoebe – “I think few or none of the rabbits will try to adapt to the change. Which person do you most agree with and why? Discuss your ideas with your partner.

Video 4: How Does Evolution Really Work?  Describe the process of natural selection  How does natural selection affect hummingbird populations?

Natural Selection is the way nature acts to select for an organism’s traits. Members of a population have variations (differences in traits) that make certain individuals better adapted to survive. (ex. size, color, structure

Individuals that are best suited, or adapted, to the environment are more likely to survive. If they survive, they reproduce and the traits that help them survive are passed on to their offspring.

Examples of modern evolution: A.Peppered moth – Pollution causes tree barks to become dark. Some moths are dark-colored and survive  there is an increase of dark moths.

B.Pesticides kill insects. Some insects have a mutation that makes them resistant to pesticides. They survive and reproduce.

C.Antibiotics – Some bacteria are resistant to antibiotics. They survive & reproduce, increasing the frequency of antibiotic resistance.