1. Protists: eukaryotes, mostly unicellular Protists and algae Biol 121, Fall 2010, Tom Buckley 15 Sep 10 What kind of group? monophyletic paraphyletic polyphyletic

2. Protist diversity and phylogeny Metabolic diversity photoautotrophs chemoheterotrophs mixotrophs (both)

3. Protist diversity and phylogeny Protists w/ plastids: origin in two-stage endosymbiosis? plastids: chloroplasts (photosynthesis) amyloplasts (starch storage) chromoplasts (pigment storage) Fig 28.2

4. gram-negative Fig 28.2

5. gram-negative observed expected -2-2 2323 -4-4 3-4 4 # of membranes 4 3-4

6. Protist diversity and phylogeny Metabolic diversity photoautotrophs heterotrophs mixotrophs All arisen repeatedly in different lineages Q: Is photoautotrophy homologous in photosynthetic protists?

7. Protist diversity and phylogeny Metabolic diversity photoautotrophs heterotrophs mixotrophs All arisen repeatedly in different lineages Q: Is photoautotrophy homologous in photosynthetic protists?

8. Protist diversity and phylogeny Metabolic diversity photoautotrophs heterotrophs mixotrophs All arisen repeatedly in different lineages Q: Is photoautotrophy homologous in photosynthetic protists?

9. Protist diversity and phylogeny Metabolic diversity photoautotrophs heterotrophs mixotrophs All arisen repeatedly in different lineages Q: Is photoautotrophy homologous in golden and brown algae?

10. In SOME spp, two genes (DHFR & TS) have fused into a single gene Expt: Sequenced genes in protists & other spp blue: fused red: separate Bacteria Q: -what is outgroup? -infer characters of ancestors

11. In SOME spp, two genes (DHFR & TS) have fused into a single gene Expt: Sequenced genes in protists & other spp blue: fused red: separate Bacteria Q: Predict whether the genes are fused in red algae

12. Protist diversity and phylogeny Key points Shared common names DO NOT imply monophyly "algae" "green algae" "molds" including fungi "amoebas" "seaweeds" & "kelp"

13. Oomycete ("water mold") Postelsia ("sea palm") Porphyra ("seaweed")

14. Protist diversity and phylogeny Other key points Fungi are closer to animals than to plants, water molds or slime molds Green algae are closer to plants than to other "algae"

15. Ecology of protists Symbioses coral reefs: dinoflagellate + animal

16. Ecology of protists Symbioses coral reefs: dinoflagellate + animal sudden oak death: Phytophthora ramorum (oomycete) + trees photo courtesy Jack Marshall, CDF

17. Ecology of protists Primary production aquatic systems algal blooms all other life excess nutrients from fertiliser, wastewater, atmosphere CO 2 CH 2 O + electrons reduction energy

18. Alternation of generations mature Laminaria 'plant': sporophyte (diploid) Laminaria (a brown alga)

19. Q: Which organisms in this diagram reduce CO 2 ? (a)herbivorous plankton (b)protistan producers (c)bacteria (d)all of the above

20. Exam I: next Mon, normal time bring 200-question scantron bring #2 pencil

21. Review