Lecture 24 Evolutionary Ecology Flashcards
Eco-Evolutionary Relationships
- Evolution and Ecology
have reciprocal effects on
each other - Phenotypes (traits)
improve survival or
reproduction (fitness) in a
given environment - Evolutionary change in
phenotypes has feedback
effects on ecological
dynamics
slide 21-22
Coevolution
- Species interactions
influence natural
selection! - Coevolution: the
evolution of interacting
species in response to
selection imposed by
the other - Can be result of
positive or negative
interactions - Bird beaks & food
- Predator-prey
antagonism
slide 23-25
Coevolution: Predators and Prey
Adaptations of predators and prey are refined through natural selection
slide 26
Coevolution: Predator Adaptations
Most predators have
acute senses to find
and identify prey.
Predator evasion»_space; Prey detection
slide 27-31
Coevolution: Predator Defenses
Prey evolve in response to avoid being eaten
* Behavior (hiding, fleeing, herding, schooling, alarm signals)
* Active self defense (large mammals defending young)
* Mechanical (quills, spines, protective armor)
* Chemical/Toxins (synthesized or acquired from plants they eat)
* Coloration
- Cryptic coloration & camouflage: patterns,
colors, and body shapes allow prey to blend in - Animals with chemical defenses often have
aposomatic coloration (warning coloration) - Mimicry & color can trick or disorient predators
to deter attack
slide 32-34
Coevolution: Warning Color & Mimicry
slide 35-36
Coevolution: “Red Queen”
- Failure to catch prey selects for smarter and more skilled predators…
- Which in turn select for faster prey that can avoid capture.
- Prey must be constantly be adapting to keep up with predator adaptations
slide 37
Coevolution: Behavioral Defenses
- Population-level defenses: coordinated behavior defends the population
- Chemical or vocal warnings
- Massive production of seeds or offspring all
at once after a long interval…
too many to all get eaten!
slide 38-39
Eco-Evolutionary Relationships
slide 40
Adaptive Radiation
period of rapid evolutionary
change in which one species
diversifies into many new species
whose adaptations allow them to
fill different niches
- A type of range expansion that
involves evolution! - Large-scale adaptive radiations
occurred after each of the big 5
mass extinctions to fill the many
unoccupied niches - Other adaptive radiations
happened with: - Evolutionary innovations such as
seeds or armored body coverings - Colonization of new regions, longdistance dispersal
Key features:
1. Common Ancestor
2. Trait-environment
relationship
3. Fitness advantage
4. Rapid bursts of speciation
slide 41-43
Adaptive Radiations: African Ciclid Fish
- Opportunity & Specialization over 2 million years
- Diversified to feed in different ways with
specialized tooth and mouth adaptations - Estimated rate of speciation: 1 every 46 years!
slide 44-45
Adaptive Radiations: Hawaii
- Multiple invasions followed by
speciation events led to multiple
adaptive radiations of species
found nowhere else:
Silverswords, honeycreepers,
drosophila, spiders
Adaptive Radiations: Hawaiian Silverswords
slide 47 - 48
Adaptive Radiations: Anolis lizards
Habitat specialization & adaptive
morphology enables rapid &
convergent speciation
slide 49-50
Rapid Evolution
We see nothing of these slow changes in
progress, until the hand of time has marked
the long lapse of ages.
-Darwin, 1859
slide 51-55
