Chapter 32: Evolution and Diversity of Modern Gymnosperms and Angiosperms (Part 2, Week 6) Flashcards
[Start 32.4 The Role of Coevolution in Angiosperm Diversification]
What is the process by which two or more species of organisms influence each other’s evolutionary pathway?
Coevolution
Since animal pollinators transfer pollen from the anthers of one flower to the stigmas of other flowers of the same species, what do pollinators thereby foster?
Foster genetic variation and enhance the potential for evolutionary change among plants.
What do you call the behavior when insects, birds, bats, and other pollinators learn the characteristics of particular flowers, visiting them preferentially?
This is known as constancy or fidelity, which increases the odds that a flower stigma will receive pollen of the appropriate species.
Animal pollinators increase the precision of pollen transfer, which reduces the amount of pollen that plants must produce to achieve pollination.
By contrast, wind-pollinated plants must produce much larger amounts of pollen because wind blown pollen reaches appropriate flowers by chance.
What are some ways flowers attract pollinators? And what influences colors and odors?
Attractive colors, odors, shapes, and sizes.
Secondary metabolites influence the colors and odors of many flowers. Flavonoids, for example, color many blue, purple, or pink flowers. More than 700 types of chemical compounds contribute to floral odors.
How do flowers reward pollinators?
How do flowers trick pollinators?
Most flowers reward pollinators with food: sugar-rich nectar, lipid- and protein-rich pollen, or both. In this way, flowering plants provide an important biological service, providing food for many types of animals.
However, some flowers “trick” pollinators into visiting or trap pollinators temporarily, thereby achieving pollination without actually rewarding the pollinator. Examples include flowers that look and smell like dead meat, thereby attracting flies, which are fooled but accomplish pollination anyway.
What is a pattern of coevolved traits between particular types of flowers and their specific pollinators?
Pollination syndromes
For example, odorless red flowers, such as those of hibiscus, are attractive to birds, which can see the color red but have a poor sense of smell.
By contrast, bees are not typically attracted to red flowers because bee vision does not extend to the red end of the visible light spectrum. Rather, bees are attracted to blue, purple, yellow, and white flowers having sweet odors.
INFORMATION on Pollination Syndromes
Animal features
Coevolved flower features
Bees
Color vision includes ultraviolet (UV), not red
Often blue, purple, yellow, white(not red) colors
Good sense of smell
Fragrant
Require nectar and pollen
Nectar and abundant pollen
Butterflies
Good color vision Blue, purple, deep pink, orange, red colors Sense odors with feet Light floral scent Need landing place Landing place Feed with long, tubular tongue Nectar in deep, narrow floral tubes
Moths
Active at night Open at night; white or bright colors Good sense of smell Heavy, musky odors Feed with long, thin tongue Nectar in deep, narrow floral tubes
Birds
Color vision, includes red Often colored red Often require perch Strong, damage-resistant structure Poor sense of smell No fragrance Feed in daytime Open in daytime High nectar requirement Copious nectar in floral tubes Hover (hummingbirds) Pendulous (dangling) flowers
Bats
Color blind Light, reflective colors Good sense of smell Strong odors Active at night Open at night High food requirements Copious nectar and pollen provided Navigate by echolocation Pendulous or borne on tree trunks
N/A
How do many plants signal fruit ripeness that influences seed-dispersal coevolution between plants and animals?
By undergoing color changes from unripe green fruits to red, orange, yellow, blue, or black.
Because birds have good color vision, they are able to detect the presence of ripe fruits and consume them before the fruits drop from plants and rot.
[Start 32.5 Human Influences on Angiosperm Diversification]
What is a process that involves artificial selection of plants or animals for traits desirable to humans?
Domestication
What was the earliest change that occured during wheat domestication which is the process by which ears of wild grain crops break apart and disperse their grains?
Process called shattering.
This explains why cultivated wheat differs from its wild relatives in shattering and other properties. This trait is disadvantagous in nature, but desirable in humans.
Corn and rice are also domesticated.
