Evolution and Community Ecology 5 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?)

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

Genes Sequences of DNA codes for each particular trait Tall, small, blue eyes, human, goldfish, pine tree Evolution is a change of genes over time

Evolution and Natural Selection Lesson 5.1 Evolution Evolution and Natural Selection 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.

4 Ways Evolution Occurs Mutation Migration Genetic Drift Natural Selection

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

Migration Movement of individuals into (immigration) or out of (emigration) a population Sometimes called “Gene Flow”

Gene Flow (Migration)

Mechanisms of Biological Evolution: Mutation and Migration Lesson 5.1 Evolution Mechanisms of Biological Evolution: Mutation and Migration Migration (gene flow) Mutation Movement of individuals into (immigration) or out of (emigration) a population. Over generation, biological evolution occurs because the fish’s gene pool has changed. This is called gene flow. Accidental change in DNA that can give rise to variation among individuals

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

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: an individual with high fitness produce more offspring and therefore passes on its genes more frequently than those with low fitness.

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

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

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.

http://www.youtube.com/watch?v=xkwRTIKXaxg Travel to Ecuador to see how the process of natural selection operates

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.

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

Impacts of Natural Selection: Resistance

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

Lesson 5.1 Evolution Artificial Selection Artificial selection: selection under human direction Throughout history, humans have chosen and bred animals and plants with beneficial traits. Why would this be important in dogs? Agriculture? Image - http://www.flickr.com/photos/carolynconner/4264882098/ (Creative Commons licensed) Geyser info source - National Park Service: http://www.nps.gov/yell/planyourvisit/noldfaith.htm

Speciation: How did we get millions of species?

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

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

Extinction Extinction: disappearance of species from Earth Lesson 5.1 Evolution Extinction Extinction: disappearance of species from Earth Generally 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 - http://www.flickr.com/photos/carolynconner/4264882098/ (Creative Commons licensed) Geyser info source - National Park Service: http://www.nps.gov/yell/planyourvisit/noldfaith.htm 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.

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

Lesson 5.2 Species Interactions The Niche Niche: describes an organism’s use of resources and functional role in a community. Niche is not only the organisms habitat but also what food it eats, how and when it produces, and what organisms it interacts with. Affected by an organism’s tolerance—its ability to survive and reproduce under changing environmental conditions 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)

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

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.

Resource Partitioning

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.

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

Predator/Prey Cycles

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

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.

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.

Symbiosis Long lasting and physically close relationship in which at least one organism benefits.

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

Parasitism and Herbivory (+/–)

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

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.

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

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.

Primary Producers (Autotrophs) Lesson 5.3 Ecological Communities Primary Producers (Autotrophs) Base of ALL food chains Makes it OWN FOOD! 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.

Consumers (Heterotrophs) Lesson 5.3 Ecological Communities Consumers (Heterotrophs) Consumers: rely on other organisms for energy and nutrients California Condor Did You Know? Scavengers, such as vultures and condors, are just large detritivores.

Types of Consumers Herbivore: eats only producers (vegetarian) Cows, sheep, deer, grasshopper, mice, rabbits

Types of Consumers Carnivore: eats other consumers Lion, hawks, snakes, alligator, whales

Types of Consumers Omnivore: eats both producers and consumers Bears, pigs, raccoons and most humans

Types of Consumers Decomposer: breaks down dead decaying organisms Critical to ecosystem health Returns nutrients Fungus, bacteria

Detritivores and decomposers: recycle nutrients within the ecosystem by breaking down nonliving organic matter

How do Organisms Use Energy Most organisms spend large amounts of time/energy in search of food and a mate.

How do Organisms Use Energy Cellular Respiration: processes of breaking down food to yield energy Gives energy to walk, read, grow, think, run, fight diseases Excess stored as fat

Glucose (sugar) + Oxygen yields carbon dioxide, water and energy REACTANTS PRODUCTS

Energy Transfer Each time one organism eats another, energy is transferred Ecosystems are all about energy flowing from one organism to another

Energy Transfer Who are the producers? Consumers? Herbivores? Carnivores? Omnivores? Decomposers? Where does the energy start?

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.

Food Web: shows many feeding relationships that are possible in a ecosystem More complex and realistic

Lesson 5.3 Ecological Communities Food Webs

Energy Flow Trophic Level: each step which energy is transferred Primary producers are always at the bottom!

Energy Flow At each trophic level about 90% of energy is lost Cellular respiration Lost to heat body and carry out living

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.

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.

Keystone Species http://www.youtube.com/watch?v=Xg62WKwA470 (Otter Keystone Species) Prairie Dogs: Keystone species http://www.youtube.com/watch?v=kEh4r4iQiBU NATURE's "Silence of the Bees“ http://www.youtube.com/watch?v=dIUo3STj6tw

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

Ecological Succession Ecosystems constantly are changing (some fast some slowly) Young Forests vs. Old Forest Quick change like fire, or volcanic eruption

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

Ecological Succession Ecological Succession: the gradual change and replacement of some or all species in a community Neighborhood changes over time

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

Ecological Succession Pioneer Species: first organisms to colonize a newly available land Lichens, bacteria, small plants often pioneers The environment changes as new species move in, adding nutrients and generating habitat.

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

Secondary Succession Occurs significantly faster than primary succession

Pioneer species in a parking lot crack

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.

Ecological Succession Climax Community: final stable community. Continues to change in small ways, but fairly stable if undisturbed

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 mussel 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.