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Themes in Biology. Lecture 1-2. diversity. evolution. interdependence. I. Diversity and unity of life. Diversity = variety. Unity = 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.
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Themes in Biology Lecture 1-2 diversity evolution interdependence
I. Diversity and unity of life Diversity = variety Unity = 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.
Kingdom Fungi Streptococcus Domain Bacteria Amoeba Kingdom Protista Domain Eukarya Domain archaea Kingdom Plantae Kingdom Animalia
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
The “tree of life” Which domain has the most kingdoms?
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
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.
Natural Selection • In a changing world, organisms have to also change to survive. • Ones with traits that help them liveand 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?
Summary: give examples of the 3 themes of biology in our local ecosystem. Oak woodlands ecosystem