1. Evolution “into” the “protista” Modern Protista represent the first eukaryotes First eukaryotes evolved from prokaryote ancestors Modern Prokaryotes represent those ancestors How?

3. Evolution of First Eukaryote(s) Forces leading to eukaryote *Increases in size *Increases in complexity Mechanisms *Infolding of cell membrane *Serial endosymbiosis of membrane-bound organelles *Combination of the two

4. Evolution of multicellularity Multicellularity evolved several times among the “protista” Complex, differentiated bodies evolved fewer times among the “protista” *Brown, green and red seaweeds *Slime molds (to be covered in the future)

5. Multicellularity - colonies All cells the same All cells the same Little or no differentiation in function Little or no differentiation in function Cooperation Cooperation *Volvox *Filaments are a kind of colony May provide “buoyancy” May provide “buoyancy”

6. Multicellularity - complex bodies Differentiation of tissues, organs Differentiation of tissues, organs *Allows larger bodies *Division of labor *Requires more complex development Several times Several times *Seaweeds – 3 lines, one to plants *Fungi *Animals Kelp forest

7. Evolution “out of” the “protista” Three exclusively multicellular kingdoms evolved from protistan lines (some multicellular, some not) *Plants (from green algae) *Animals (from flagellated protozoa – choanoflagellates) *Fungi (from flagellated protozoa – choanoflagellates) When? Just before the Cambrian period *Fungi – 1100-800 mya (in sea, later joined plants on land) *Animals – 1100-800 mya (in sea) *Plants – 400 mya (on land)