1. Lecture 1-2 Themes in Biology diversity interdependence evolution

2. I. Diversity and unity of life Diversity = varietyUnity = things in common Over 1.5 million species exist on Earth. It can be 1-celled, or a whale with a trillion cells. Each species is different from every other. All living things share a genetic code. All life descended from a single common ancestor. Diversity came from genetic changes happening over time.

3. Domain archaea Streptococcus Domain Bacteria Domain Eukarya Kingdom Fungi Amoeba Kingdom Protista Kingdom Plantae Kingdom Animalia

4. Three domains of life Archaea: simple cells, most ancient organisms Bacteria: simple cells Eukarya: cells with more complexity. All multicellular life is in this domain. 4 kingdoms of eukaryotes: Protista, Plantae, Fungi, and Animalia

5. The “tree of life” Which domain has the most kingdoms?

6. II. Interdependence of organisms Ecosystems are living things interacting with each other and their environment. Life has changed our planet. Humans have impacted all life on Earth. What process put oxygen into the air? rainforest Slash and burn farming

7. III. Evolution of life Populations change, or evolve, over time. Over time, new species arise, others go extinct. Evolution explains how life today is related to life in the past.

8. Natural Selection In a changing world, organisms have to also change to survive. Ones with traits that help them live and reproduce will continue (natural selection). Adaptations are traits that help an organism survive. Those traits, over time, may cause a change in the whole population. (descent with modification). How are the jack rabbit, musk ox, and snow hare adapted to their environments?

9. Oak woodlands ecosystem Summary: give examples of the 3 themes of biology in our local ecosystem.