reproduction and attracting mates: flowers (including zygomorphy , pollination, flowering time)

Reproduction and attracting mates: Flowers (including zygomorphy,

pollination, flowering time)

Questions

• Discussions: – Maria M: posting paper and questions for this

week– Jon: will be picking a paper to post for next week– Peter Stevens is taking students around Orchid

house at gardens at 10 am probably on Saturday. Let him or me know if you are interested.

• Any questions?

What’s a flower? What’s it for?

FernsGymnosperms

Angiosperms

Flower evolution

• 130-250 mya – Modified leaves (why?)

What’s a flower? What’s it for?

• Reproductive structure of angiosperms: – Heterosporangiate typically

consisting of androecium, gynoecium, usually surrounded by a perianth and borne on an axis or receptacle

Flower morphology

• Pedicel• Flower parts in whorls: (4,5’s or 3’s)

– Calyx (sepals), Corolla (petals), Androecium (stamens with anther, filament), Gynoecium (pistils with stigma, style, ovary)

Symmetry

• Actinomorphic (radially symmetric) vs zygomorphic (1 bisecting line of symmetry)

• Asymmetric: uncommon (Cannanceae, Marantaceae)

Flower vs. Inflorescence

Cercidiphyllum

Breeding systems: outcrossing and inbreeding

• Spatial: – Flower: perfect (both sexes) vs. imperfect (1 sex)– Plant: monoecious (1 sex) vs. dioecious (both

sexes)– Heterostyly

Breeding systems: outcrossing and inbreeding

• Temporal: Dichogamy– Protandry: stamens before carpels– Protogyny: carpels before stamens

Pollination syndromes

• Animal: Insects, birds, bats– Rewards: Nectar, pollen, fragrance, oils– Attract pollinators: Scent, color patterning,

mimicry (Orchidceae)

• Abiotic: Wind and water• Self pollinated, Cleistogamous

Evolution of oil production and collection

• Renner and Schaefer. 2010. Phil. Trans. R. Soc. B. 365:423-435.– Bees collect oil for larvae and pollinate flowers– Question: When and how often oil-offering

flowers and oil-foraging bees evolved?

Oil and bees

• Renner and Schaefer. 2010. Phil. Trans. R. Soc. B. 365:423-435.– Question: When and how often oil-offering

flowers and oil-foraging bees evolved?• Oil flowers evolved at least 28 times and lost 36-40

times. Oldest just after the K/T boundary65 mya in America (Melpighiaceae) and Africa (Curcurbitaceae, and Laurasia (Myrsinaceae) taxa

• Bees evolved oil foraging at least 7 times with earliest at least 53-56 Mya (but probably older)

Phylogenies

Build ups

Evolution of floral morphology

Evolution of floral morphology

Question

• Is flower symmetry associated with changes in speciation rates mediated via pollinators?

Question

• Is flower symmetry associated with changes in speciation rates mediated via pollinators?– Suggest bilaterally symmetrical flowers can

restrict pollinator access to flowers, direct pollen placement, and lead to greater reproductive isolation

– Predict that bilaterally symmetrical flowers have higher speciation rates than radially symmetrical flowers

Question

• Is flower symmetry associated with changes in speciation rates mediated via pollinators?– Corolla symmetry data for animal pollinated

families from the literature– Sister-group comparisons (40 zygomorphic clades

and 19 comparisons)• Building an angiosperm tree and mapping on

zygomorphy• Looking for the actinomorphic sister • Getting number of species in family from literature

Evolution of floral morphology

Zygo-Actino species* = Actino† = Zygo

Question

• Is flower symmetry associated with changes in speciation rates mediated via pollinators?– In 15/19 comparisons zygomorphic clade was

more diverse than actinomorphic clade