Natural Selection Charles Darwin What is Natural Selection

Natural Selection Charles Darwin

What is Natural Selection? • Changes that occur in an organism over time that allow it to better survive in its environment.

Where did the idea of natural selection come from? Charles Darwin sailed around the world between 18311836. He concentrated his studies on a group of islands called the Galapagos Islands.

What did Darwin find during his travels? • The diversity of living species was far greater than anyone had previously known!! • These observations led him to develop theory of evolution and natural selection. • Darwin noticed two major groups of organisms first: tortoises and finches.

How did tortoises and birds differ among the islands of the Galapagos? • Each island had its own type of tortoises and birds that were clearly different from other islands.

How does natural selection work?

• Over time, individuals with characteristics that best suit their environment survive and produce offspring. • Those that do not have them, die off.

– These “good” characteristics are carried on by the offspring and into future generations.

Natural Selection at work- How will the color of the fish lead to natural selection?

Brain. POP Movie DIRECTIONS: 1) Go to: http: //www. brainpop. com/science/ecolog yandbehavior/naturalselection/ 2) If you need to sign in, use the following: 1) Username: camdenny 2) Password: school 3) Watch the video on natural selection. 4) Return to powerpoint to finish your notes

Do we effect natural selection? • How might we (humans) effect natural selection? __________________

Artificial Selection • Nature provides variation, humans select variations that are useful. • Example - a farmer breeds only his best livestock

Artificial selection • All breeds descended from wolves • Dogs now are selected for color, hair length, size, behavior, & even oddities.

Artificial selection • USDA spends $$ to breed new varieties of wheat and corn that are resistant to rust, fungi, etc.