LIFESCI 1 Lecture Notes - Lecture 1: Coevolution, Flowering Plant, Angraecum
Life Sciences 1
Animal Diversity 1 Take Home Assignment
1. Now you have seen both animals and plants, and you know that most Angiosperms require
an animal pollinator for reproduction to occur. Below on the left you will see a flower that is
pollinated by a bee (a generalist pollinator) which visits a lot of flowers of different species.
Below on the right you will see a flower that can only be pollinated by a single species of
moth (a specialist pollinator) which only visits this species of plant.
List and describe two advantages and disadvantages for plants with generalist or specialist
pollinators.
Generalist Pollinator
Specialist Pollinator
Advantages
Greater reproductive success and
diversification because it does not
depend on one specific pollinator
and hybridization can occur.
Allows for greater efficiency of
pollination because the benefits and
rewards of the flower is specific to a
pollinator.
Allows for many different
pollinators to pollinate the flowers
which results in greater
availability.
Provides a constant source of
pollinator because a specific
pollinator will always travel to the
same species. Thus, all the pollen
that is picked up will not be gone to
waste.
Disadvantages
Involves the risk of inefficient
pollination because there could be
pollinators that doesn’t pollinate
well or efficiently with a specific
type of flower.
The plant becomes very dependent
on the specific pollinator species,
thus a decrease in the pollinator will
result in a decrease in the plant.
Greater competition amongst the
plants for pollinators.
Decreases the genetic diversity
because the same pollinators
pollinate the same type of flowers.
2. Angraecum sesquipedale (a.k.a. Darwin’s Orchid) is a species of Angiosperm found in
Madagascar (See the photo on the right above). When Charles Darwin first saw it in 1862, he
noticed the very long spur (up to 30 cm) at the end of which the nectar is produced. He was
so surprised by this uncommon feature that he wrote in a letter to J. Bateman (the guy who
discovered the plant): “Good Heavens! What insect can suck it?”
Both Darwin and A.R. Wallace predicted the existence of an insect with a proboscis so long
that it was able to get the nectar and successfully pollinate this flowers. In 1867 Wallace said:
"That such a moth exists in Madagascar may be safely predicted; and naturalists who visit
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Document Summary
Animal diversity 1 take home assignment: now you have seen both animals and plants, and you know that most angiosperms require an animal pollinator for reproduction to occur. Below on the left you will see a flower that is pollinated by a bee (a generalist pollinator) which visits a lot of flowers of different species. Below on the right you will see a flower that can only be pollinated by a single species of moth (a specialist pollinator) which only visits this species of plant. List and describe two advantages and disadvantages for plants with generalist or specialist pollinators. Greater reproductive success and diversification because it does not depend on one specific pollinator and hybridization can occur. Allows for many different pollinators to pollinate the flowers which results in greater availability. Involves the risk of inefficient pollination because there could be pollinators that doesn"t pollinate well or efficiently with a specific type of flower.
