Agenda – 04.29.2015 Warm-up 10.3 Reading Preview and Bioterms 10.3 Notes The Making of the Fittest

Warm - up Tell me what you know about Natural Selection When you are done start working on 10.3 reading preview

OBJECTIVES Compare artificial selection to natural selection Examine the factors Darwin considered in forming his theory of natural selection Summarize the four principles of natural selection

KEY CONCEPT Darwin proposed natural selection as a mechanism for evolution.

Vocabulary Artificial Selection – process by which humans modify a species by breeding it for certain traits (304) Heritability – ability of a trait to be passed from one generation to the next (304). Natural selection – mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals (305). Population – all of the individuals of a species that live in the same area (306). Fitness – measure of an organism’s ability to survive and produce offspring relative to other members of a population (307).

Who Developed the Theory of Evolution by Natural Selection? Charles Darwin His observations: Variation: The difference in the physical traits of an individual from those of other individuals in a group. Adaptation: The features that allow an organism to better survive in its environment Example: The different beak types of different Galapagos finch species. Fossils: found evidence of species changing over time which lead him to believe Earth was much more than 6000 years old.

Several key insights led to Darwin’s idea for natural selection. Darwin noticed a lot of variation in domesticated plants and animals. Artificial selection is the process by which humans select traits through breeding. neck feathers crop tail feathers

Does not improve fitness Genetic modification Ex: dog breeds Diversity Natural selection is a mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals. Heritability is the ability of a trait to be passed down. Darwin proposed that adaptations arose over many generations. Artificial Selection Natural Selection Imposed by humans Selective breeding Does not improve fitness Genetic modification Ex: dog breeds Diversity Variation Heritable Driven by natural processes/environment

There is a struggle for survival due to overpopulation and limited resources. A Population is all the individuals of a species that live in an area. Example: All crows that are around Orange Glen High School. (ON THE NEXT PAGE)

Natural selection explains how evolution can occur. There are four main principles to the theory of natural selection. variation overproduction adaptation descent with modification DESCENT with MODIFICATION ADAPTATION OVERPRODUCTION VARIATION

Fitness is the measure of survival ability and ability to produce more offspring. What if….. A bird outcompletes other birds for food in a particular area and that bird can produce many more eggs, this bird has a high FITNESS

Natural selection acts on existing variation. Natural selection can act only on traits that already exist. Structures take on new functions in addition to their original function. wrist bone five digits

Exit Ticket In your own words, what is the difference between Natural Selection and Artificial Selection. What did Charles Darwin observe in the world that helped him to come up with his theory of Natural Selection? List the 4 main principles of Natural Selection