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

3. Genes
Sequences of DNA codes for each particular trait
Example: Blue eyes, tall, short

4. Evolution and Natural Selection
Lesson 5.1 Evolution
Evolution and Natural Selection
Evolution-change of genes over time
Gene pool: All the genes present in a population
Biological evolution: 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. 4 Ways Evolution Occurs
Mutation
Migration
Genetic Drift
Natural Selection

6. Mutation
Accidental change in DNA that can give rise to variation among individuals

7. Migration
Movement of individuals into (immigration) or out of (emigration) a population
Sometimes called “Gene Flow”
Over generation, biological evolution occurs because the fish’s gene pool has changed.

8. Gene Flow (Migration)

9. Genetic Drift
Evolution that occurs by chance
Natural Disasters
Run in with human nets, etc.

10. Natural Selection
Process by which traits useful for survival and reproduction are passed on more frequently than those that are not
Survival of the fittest:
-high fitness produce more offspring & therefore pass on its genes more frequently than those with low fitness.

11. 3 Conditions for Natural Selection
Organisms produce more offspring than can survive.
Nature has limitations (limiting factors)
Struggle for survival

12. 3 Conditions for Natural Selection
(2) Individuals vary in characteristics, some of which are heritable
Not every species is same
Some fish are faster, darker, smaller
Genes different
Heritable Differences

13. 3 Conditions for Natural Selection
(3) Individuals vary in fitness, or reproductive success
Survival of Fittest
Fittest for its environment
Adaptation: an inherited trait that increases an organisms chance of survival and reproduction.

14.
Travel to Ecuador to see how the process of natural selection operates

15. Adaptations Desert plants have small or no leaves at all
The insect that blends in and is able to survive may be more likely to reproduce.

16. White coat of polar bear helps in hunting
Results of natural selection all around us
NATURE SELECTS
Adaptations
Big ears of desert jack rabbit allow it to cool off quickly
Long neck of giraffe allow it to reach food

17. Resistance
Resistance: ability of one or more organisms to tolerate a chemical designed to kill it
Able to survive & reproduce
Pesticide resistance
Antibiotic resistance

18. Impacts of Natural Selection: Resistance

19. Lesson 5.1 Evolution
Artificial Selection
Artificial selection: selection under human direction
humans have chosen & bred animals & plants with beneficial traits.
Image - (Creative Commons licensed)
Geyser info source - National Park Service:

20. Speciation: How did we get millions of species?

21. Speciation
Process by which new species are generated
Can occur in a number of different ways most important way is called:
allopatric speciation– Geographic Isolation
occur due to major rivers separating populations, lakes drying up and forming separate lakes, etc.
resulted in every form of life on Earth— today and in the past

22. The canyon is a barrier to dispersal by small mammals, and as a consequence the isolated populations can diverge.

23. Extinction Extinction: disappearance of species from Earth
Lesson 5.1 Evolution
Extinction
Extinction: disappearance of species from Earth
occurs gradually, one species at a time, when environmental conditions change more rapidly than the species can adapt
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.

24. Lesson 5.2 Species Interactions
The zebra mussel has completely displaced 20 native mussel species in Lake St. Clair.

25. Lesson 5.2 Species Interactions
The Niche
Niche: describes an organism’s use of resources and functional role in a community.
Affected by an organism’s tolerance
Often restricted by competition
Tolerance: ability to survive and reproduce under changing environmental conditions.
Specialists: have restricted tolerance (ex: panda bears)
Generalists: wide tolerance ranges (ex: rats)

26. Fundamental vs. Realized Niche
Fundamental = Without competition Realized = With competition (restricted niche)

27. Competition
Organisms compete when they seek the same limited resource.
In rare cases, one species can entirely exclude another from using resources.
To reduce competition, species often partition resources, which can lead to character displacement.

28. Lesson 5.2 Species Interactions
Competition
Intraspecific competition: competition among members of the same species
Interspecific competition: competition among members of two or more different species
Competitive exclusion: in rare cases, one species can entirely exclude another from using resources.

29. Resource Partitioning

30. Predation (+/-)
The process by which a predator hunts, kills, and consumes prey
Causes cycles in predatory and prey population sizes

31. Predator/Prey Cycles

32. Predation
Defensive traits such as camouflage, mimicry, and warning coloration have evolved in response to predator-prey interactions.

33. Predation
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.

34. Coevolution
The Madagascar star orchid produces nectar at the bottom part of its slim, foot-long throat. After observing a specimen, Charles Darwin predicted the existence of a moth with a proboscis long enough to reach that nectar. Sure enough, decades later the giant hawk moth of Madagascar was discovered.

35. Parasitism and Herbivory (+/–)
Parasitism: One organism (the parasite) relies on another (the host) for nourishment or for some other benefit
Herbivory: An animal feeding on a plant

36. Parasitism and Herbivory (+/–)

37. 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

38. Mutualism (+/+) and Commensalism (+/0)
Clown Fish and Sea Anemones demonstrate mutualism because Anemones provide the Clown Fish with protection from predators while Clown fish defend the Anemones from Butterfly fish who like to eat Anemones.

39. Mutualism (+/+) and Commensalism (+/0)
Barnacles adhering to the skin of a whale or shell of a mollusk

41. Lesson 5.3 Ecological Communities
The sun provides the energy for almost all of the ecological communities and species interactions on Earth.
Energy is not cycle but moves in a one-way stream used by each organism.

42. Primary Producers (Autotrophs)
Lesson 5.3 Ecological Communities
Primary Producers (Autotrophs)
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.

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

44. Lesson 5.3 Ecological Communities
Energy in Communities
Trophic level: an organism’s rank in a feeding hierarchy
Primary producers always occupy first trophic level of any community.
only about 10% of the energy available at any trophic level is passed to the next; rest is lost to the environment as heat.
Pyramid of Energy

45. 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.

46. A food chain is simple, direct, and linear
A food chain is simple, direct, and linear. It is a single pathway of feeding relationships. Notice the direction the arrow points (); It points in the direction of the energy is being transfer, NOT “what ate what”. The arrow points to the organism that RECEIVES the energy.

47. Lesson 5.3 Ecological Communities
Food Webs
Food web: Shows the overlapping and interconnected food chains present in a community. This occurs because most organisms eat more than one organism and are consumed by more than one organism

48. Lesson 5.3 Ecological Communities
Keystone Species
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.

49. 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

50. Ecological Disturbances
Lesson 5.4 Community Stability
Ecological Disturbances
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.
Succession: community experiences predictable series of changes over time caused but severe disturbances.
Forest fire

51. Lesson 5.4 Community Stability
Primary Succession
Primary succession: occurs when there are no traces of the original community remaining, including vegetation and soil, community is rebuilt from scratch
Pioneer species: are the first to colonize.
The environment changes as new species move in, adding nutrients and generating habitat.

52. Lesson 5.4 Community Stability
Secondary Succession
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

53. 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.

54. Lesson 5.4 Community Stability
Climax Communities
Ecologists once thought succession leads to stable “climax” communities.
Climax communities: stable community that completes succession process
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”

55. Lesson 5.4 Community Stability
Invasive Species
Invasive species: nonnative organisms that spread widely in a community.
Invasive species can be a community disturbance and a major problem in many parts of the world. Ex: zebra muscle
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.