1. Evolution and Community Ecology5
CHAPTER
Placeholder opening page, but maybe we can duplicate the look of the SE chapter opener page by using the same fonts and colors (and maybe that Ch 14 icon?)

2. Black and White, and Spread All Over
Zebra mussels and quagga mussels were accidentally introduced into Lake St. Clair in the late 1980s.
They have since spread throughout the Great Lakes system and connecting rivers.
The invasive mussels have a high economic and ecological cost.
Silent Invaders: Episode 2 (21 min)
Talk About It The Great Lakes are home to more than 20 native mussel species. Why are the zebra and quagga mussels so much more destructive than the lakes’ native mussels?

3. Lesson 5.1 Evolution
Scientists have identified and described over 1.5 million species. Millions more have yet to be discovered.

4. Evolution and Natural Selection
Lesson 5.1 Evolution
Evolution and Natural Selection
Gene: A sequence of DNA that codes for a particular trait
Gene pool: All the genes present in a population
Biological evolution: The change in a population’s gene pool over time
A starting population of fish. Genes control the color and pattern of the fish’s scales.

5. Mechanisms of Biological Evolution: Mutation and Migration
Lesson 5.1 Evolution
Mechanisms of Biological Evolution: Mutation and Migration
Mutation
Migration (gene flow)
Accidental change in DNA that can give rise to variation among individuals
Movement of individuals into (immigration) or out of (emigration) a population

6. Lesson 5.1 Evolution
Mechanisms of Biological Evolution: Genetic Drift and Natural Selection
Genetic Drift
Natural Selection
Process by which traits useful for survival and reproduction are passed on more frequently than those that are not
Evolution that occurs by chance

7. Conditions of Natural Selection
Lesson 5.1 Evolution
Conditions of Natural Selection
Image - (Creative Commons licensed)
Geyser info source - National Park Service:
(1) Organisms produce more offspring than can survive.
(2) Individuals vary in characteristics, some of which are heritable.
(3) Individuals vary in fitness, or reproductive success.
Did You Know? Darwin privately researched natural selection for two decades before publishing On the Origin of Species.

8. Artificial Selection NO! Selection under human direction
Lesson 5.1 Evolution
Artificial Selection
Selection under human direction
Throughout history, humans have chosen and bred animals and plants with beneficial traits.
NO!
Image - (Creative Commons licensed)
Geyser info source - National Park Service:
Is this real?

9. Speciation Process by which new species are generated
Lesson 5.1 Evolution
Speciation
Process by which new species are generated
Can occur in a number of different ways; the most important way is called allopatric speciation
Has resulted in every form of life on Earth— today and in the past
Image - (Creative Commons licensed)
Geyser info source - National Park Service:
Allopatric Speciation

10. Extinction The disappearance of species from Earth
Lesson 5.1 Evolution
Extinction
The disappearance of species from Earth
Generally occurs gradually, one species at a time, when environmental conditions change more rapidly than the species can adapt
There are five known mass extinction events, each of which wiped out a large proportion of Earth’s species.
Image - (Creative Commons licensed)
Geyser info source - National Park Service:
Trilobites
Marine arthropods that went extinct at the end of the Permian period.
Did You Know? During the Permo-Triassic extinction 250 million years ago, 70% of all land species and 90% of all marine species went extinct.

11. Lesson 5.2 Species Interactions
2:24 min
12 min
The zebra mussel has completely displaced 20 native mussel species in Lake St. Clair.

12. Lesson 5.2 Species Interactions
The Niche
Describes an organism’s use of resources and functional role in a community
Affected by an organism’s tolerance—its ability to survive and reproduce under changing environmental conditions
Often restricted by competition

14. Competition Two organisms cannot occupy the same niche.
This is a problem because many species use the same resources. This creates competition among species.
There are 3 ways species have addressed this competition.
Competitive Exclusion
One species excludes the other species forcing it to leave or die out.
Ex: Kudzu vine is quickly out-competing many plants.

15. Competition Resource Partitioning
Each species specializes their niche so there is very little over-lap between species.
This reduces competition between species.

16. Competition Character displacement
Lesson 5.2 Species Interactions
Competition
Character displacement
Species have evolved physical characteristics to obtain resources in slightly different ways.
Ex: Haitian Anoles
Different dewlap colors to attract mates.

17. Lesson 5.2 Species Interactions
Predation (+/–)
The process by which a predator hunts, kills, and consumes prey
Causes cycles in predatory and prey population sizes
Defensive traits such as camouflage, mimicry, and warning coloration have evolved in response to predator-prey interactions.
Some predator-prey relationships are examples of coevolution, the process by which two species evolve in response to changes in each other.
Rough-Skinned Newt
Did You Know? A single rough-skinned newt contains enough poison to kill 100 people. Unfortunately for the newt, its predator, the common garter snake, has coevolved resistance to the toxin.

18. Parasitism and Herbivory (+/–)
Lesson 5.2 Species Interactions
Parasitism and Herbivory (+/–)
Parasitism: One organism (the parasite) relies on another (the host) for nourishment or for some other benefit. Ex: Ticks, tape worms
Herbivory: An animal feeding on a plant
Hookworm (a parasite)
Did You Know? One study of Pacific estuaries suggests that parasites play an important role in keeping these ecosystems healthy by controlling host populations.

19. Mutualism (+/+) and Commensalism (+/0)
Lesson 5.2 Species Interactions
Mutualism (+/+) and Commensalism (+/0)
Mutualism: a relationship in which two or more species benefit
Commensalism: a relationship in which one species benefits while the other is unaffected
Lichen: a symbiotic relationship between a fungus and a photosynthetic partner, such as an alga
Did You Know? Symbiosis describes a long-lasting and physically close relationship between species in which at least one species benefits.

20. Structural and Behavior Adaptations
Structural Adaptations
are body structures that allow an animal to find and consume food, defend itself, and to reproduce its species.
Ex: claws, beaks, feet, armor plates, skulls, teeth, long neck, camouflage, chemicals (skunk)
Behavioral Adaptations
changes in its pattern of action to better suit its environment.
Ex: Methods of gathering & storing food, Hibernating, Finding shelter, Defending oneself, Migrating
(4:36min)

21. Successful Predator/Prey Adaptations
Predators
Here are some adaptations that make animals successful predators:
Are they Structural or Behavioral?
SHARP TEETH
CAMOUFLAGE
SHARP CLAWS
EYES IN FRONT
SPEED & AGILITY

22. Successful Predator/Prey Adaptations
LIVE IN GROUPS
POISON OR STINGS
EYES ON SIDE OF HEAD
BUILT FOR SPEED
CAMOUFLAGE
12 min

23. Lesson 5.3 Ecological Communities
The sun provides the energy for almost all of the ecological communities and species interactions on Earth.

24. Primary Producers (Autotrophs) Auto = Self, Troph = eat
Lesson 5.3 Ecological Communities
Primary Producers (Autotrophs) Auto = Self, Troph = eat
Capture energy from the sun or from chemicals and store it in the bonds of sugars, making it available to the rest of the community
Energy from the sun is captured by plants, algae, or bacteria through photosynthesis.
Energy from chemicals is captured by some bacteria through chemosynthesis.
Did You Know? Deep-sea vents, far from sunlight, support entire communities of fish, clams, and other sea animals, which depend on energy converted through chemosynthesis.

25. Consumers (Heterotrophs) Hetero = others, Troph = eat
Lesson 5.3 Ecological Communities
Consumers (Heterotrophs) Hetero = others, Troph = eat
Rely on other organisms for energy and nutrients
Herbivores: plant-eaters
Carnivores: meat-eaters
Omnivores: combination-eaters
Detritivores and decomposers: recycle nutrients within the ecosystem by breaking down nonliving organic matter
Use oxygen to break bonds in sugar and release its energy through cellular respiration (primary producers do this, too)
California Condor
Did You Know? Scavengers, such as vultures and condors, are just large detritivores.

26. Lesson 5.3 Ecological Communities
Energy in Communities
An organism’s rank in a feeding hierarchy is its trophic level.
Primary producers always occupy the first trophic level of any community.
In general, only about 10% of the energy available at any trophic level is passed to the next; most of the rest is lost to the environment as heat.
Pyramid of Energy

27. Numbers and Biomass in Communities
Lesson 5.3 Ecological Communities
Numbers and Biomass in Communities
A trophic level’s biomass is the mass of living tissue it contains.
In general, there are more organisms and greater biomass at lower trophic levels than at higher ones.

28. Lesson 5.3 Ecological Communities
Food Chains and Webs
Food chain: Linear series of feeding relationships
Food web: Shows the overlapping and interconnected food chains present in a community

29. Lesson 5.3 Ecological Communities
Keystone Species
Species that have strong and/or wide-reaching effects on a community
Removal of a keystone species can significantly alter the structure of a community.

30. Lesson 5.4 Community Stability
A 2010 report on invasive species suggests that they cost the U.S. $120 billion a year in environmental losses and damages.
Invasive kudzu

31. Lesson 5.4 Community Stability
Ecological Disturbances (6.20
A community in equilibrium is generally stable and balanced, with most populations at or around carrying capacity.
Disturbances or changes in the environment can throw a community into disequilibrium.
Severe disturbances can cause permanent changes to a community and initiate a predictable series of changes called succession.
Forest fire

32. Lesson 5.4 Community Stability
Primary Succession
Occurs when there are no traces of the original community remaining, including vegetation and soil
Pioneer species, such as lichens, are the first to colonize.
The environment changes as new species move in, adding nutrients and generating habitat years

33. Lesson 5.4 Community Stability
Secondary Succession
Occurs when a disturbance dramatically alters a community but does not completely destroy it
Common after disturbances such as fire, logging, or farming
Occurs significantly faster than primary succession

34. Lesson 5.4 Community Stability
Succession in Water
Primary aquatic succession occurs when an area fills with water for the first time.
Disturbances such as floods or excess nutrient runoff can lead to secondary aquatic succession.

35. Lesson 5.4 Community Stability
Climax Communities
Ecologists once thought succession leads to stable “climax” communities.
Today, ecologists see communities as temporary, ever-changing associations of species.
Communities are influenced by many factors and constant disturbances.
Beech-maple forest, a classic “climax community”

36. Invasive Species Nonnative organisms that spread widely in a community
Lesson 5.4 Community Stability
Invasive Species
Nonnative organisms that spread widely in a community
A lack of limiting factors such as predators, parasites, or competitors enables their population to grow unchecked.
Not all invasive species are harmful.
Did You Know? Although the European honeybee is invasive to North America, it is beneficial because it pollinates our agricultural crops.