BIO 2137 Lecture Notes - Lecture 10: Allogamy, Multiple Fruit, Hymenoptera
21 Jan 2021
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Document Summary
The first megafossils, early cretaceous period (130 mya) in tropical regions. Worldwide dominance in vegetation by 90 mya. Many modern families and some modern genera already existed by 75 mya. The rapid development as far as we can judge all the higher plants within recent geological times is an abominable mystery. It is a perplexing phenomenon for those who believed in gradual evolution. Stamens (1-3) fused with style and stigma to create the column. Epiphytes (mass majority), saprophytes or even subterranean. Two fused carpels, one locule, one ovule. 5 stamens, anthers connate, adnate to corolla. Sepals absent or reduced to pappus (bristles) Flowers open at different times (better chance for different pollinators = cross pollination) Birds, insects, mammals, etc) are the main means of pollination. Animals are in part responsible for the evolution of flowers. Allow allogamy (cross-fertilization) to become common across angiosperms. Gymnosperms mass pollination by wind inefficient. Angiosperms flower with attracting features gets visited more often.
