Themes in Biology

Lecture 1-2Themes in Biology

diversityinterdependenceevolutionI. Diversity and unity of lifeDiversity = varietyUnity = things in commonOver 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.

Domain archaeaStreptococcusDomain BacteriaDomain Eukarya

Kingdom Fungi

AmoebaKingdom Protista

Kingdom Plantae

Kingdom Animalia

Three domains of life

Archaea: simple cells, most ancient organismsBacteria: simple cellsEukarya: cells with more complexity. All multicellular life is in this domain.4 kingdoms of eukaryotes: Protista, Plantae, Fungi, and Animalia

The tree of lifeWhich domain has the most kingdoms?II. Interdependence of organismsEcosystems 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?rainforestSlash and burn farmingIII. Evolution of lifePopulations 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 SelectionIn 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 hareadapted to their environments?

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