BIOL 111 Lecture 17: Angiosperms Flowers and Fruits

• School: McGill University
• Department: Biology
• Course: BIOL 111
• Professor: Andrew Hendry

Document Summary

Recall: advantage of pollen and seed:break connection between plants and wet environments. One lineage produces an unusual amount of descendants, explosion of species. All allow more efficient water, pollen, seed transport. Flowers selection lead quickly to reproductive isolation. Breeding together too much leads to less diversity. Later plants enclosed carpels and stamens in sepals and petals. 4 structures (carpels, stamen, sepals, petals) diversified to huge variety. Pollination is involved in speciation of complex lineage. Experimental crosses and genetic analysis show large changes with single mutations. Hybrid of hummingbird and bee pollinated flowers, different shapes, colours. Allele with darker hues reduced bee visitation. Allele with higher nectar attracted hummingbirds much more. Simple changes lead to pollinator shifts (colour, nectar spur length, time for flowering (night vs day) Manipulate one trait, insert purple into white flower. Manipulate visitor behaviour to maximize pollen transfer. Putting pollen on different parts of body to ensure it only gets transferred to their species.