M1202_Plant_Evolution

Materials

Patel NH (2006) How to build a longer beak. Nature 442, 515-516

Comes et al. (2008) Plant speciation in continental island floras as exemplified by Nigella Aegean Archipelago . Phil. Trans. R. Soc. B (2008) 363, 3083–3096

Bomblies et al. (2007) Autoimmune Response as a Mechanism for a Dobzhansky-Muller-Type Incompatibility Syndrome in Plants. PloS Biology

1. The Darwin Finches of Galapagos are a famous example for adaptive radiation. Recently, the molecular mechanisms underlying the different beak formation have been elucidated. Explain briefly, how different beaks are produced.

2. Describe in short (maximum 1/3 page) the central findings on allopatric speciation of Nigella in the Aegeis (Comes et al. 2008)

3. The ABC-model of flowering has been developed based on mutants in Arabidopsis and has been generalized for "the" Angiosperm flower. Describe briefly, how this model contributes to our understanding of Angiosperm diversity and what the limitations of this model are (Remark: to answer this question, you have to read Litt 2006).

4. You cross a maternal plant with the SI genotype S₁S₁ with pollen from a S₁S₂ plant. What percentage of pollen would germinate in case of (a) gametophytic, and (b) sporophytic self incompatibility?

5. Propagation bareers are a central component of Mayr's speciation concept. A manifestation of early stages of such bareers is a reduced fitness of hybrids. A recent report claims that there is a link to plant defence. Can you describe briefly the evidence for this idea?