Theory of evolution

What is a theory? Shows cause and effect relationships Based on experimental results Based on several assumptions Used to make predictions

Who is the considered the father of evolutionary theory?

Charles darwin On The Origin of Species

Galapagos islands

Sea turtles

14 species of finches

5 main ideas 1. Overproduction 2. Competition 3. Variation 4. Natural Selection 5. Speciation

overproduction Produce tons of offspring to ensure that your genes are passed on, since most of your offspring will die.

Competition Intraspecies Interspecies

What can species compete for?

Variation No two individuals are alike. This changes everyone’s chances of survival and reproduction. Our variety of genes are passed on…

Natural selection This is survival of the fittest Those who are better adapted survive to reproduce and pass on good genes. Those who don’t, die, and do not pass on their bad genes.

speciation New species arise by accumulated inherited variations. How can you tell something is a new species?

How did we evolve? http://www.bbc.co.uk/schools/gcsebitesize/ science/ocr_gateway_pre_2011/environment /4_survival_of_fittest4.shtml

Types of adaptations Structural Physiological Behavioral Turn to page 98 and list 3 examples of each Structural Physiological Behavioral

behavioral Watch some of these crazy behavioral adaptations by animals http://www.youtube.com/watch?v=L54bxmZ y_NE http://www.youtube.com/watch?v=fPXkUXX FoCw Was the Gibbon’s behavior adapative?

Rate of evolution How fast does evolution occur? GRADUALISM- evolution is slow and continuous over many years. This is supported by fossil records of many species. Why change if your environment never does?

equilibrium Plants or animals that show little change over thousands of years are said to be in equilibrium.

Punctuated equilibrium When a species encounters extreme environmental changes, it is forced to change. If it dies off, other species come along and occupy that niche. That species goes through rapid adaptations as it fills the niche. Tons of changes happen very fast. This graphs shows 2 species and their niche overlap