Ecosystems & Communities: Organisms and their Environments
description
Transcript of Ecosystems & Communities: Organisms and their Environments
1
Ecosystems & Communities:Organisms and their Environments
Chapter 15
2
Ecosystems have living and non-living components
15.1 What are ecosystems?
3
15.1 What is an Ecosystem?• A community of biological organisms plus the non-
living components with which the organisms interact.• Living organisms are not self-sufficient. They need
energy and raw materials.
4
5
6
15.1 What is an Ecosystem?• The biotic environment consists of all the living
organisms within an area and is often referred to as a community.
• The abiotic (aka non-living or physical) environment, often referred to as the organisms’ habitat, consists of:• the chemical resources of the soil, water, and air,
such as carbon, nitrogen, and phosphorus• the physical conditions, such as the temperature,
salinity (salt level), moisture, humidity, and energy sources
7
Which scenario below exemplifies an ecosystem?1. A group of organisms of the same species living in the
same place at the same time2. Different species interacting together at the same
place and time3. Different species interacting with each other at the
same time in a desert4. A smaller species living on a larger species in a
mutually beneficial relationship
8
Take-Home Message 15.1• An ecosystem is all of the living organisms in a habitat
as well as the physical environment. Ecosystems are found not just in obvious places such as ponds, deserts, and tropical rainforests but also in some unexpected places, like the digestive tracts of organisms or the shell of a beetle.
9
Challenge Question 15.1• An ecosystem is made of two components: the biotic
environment, or community, consisting of the living organisms within an area, and the physical environment, or the habitat in which these organisms live. A habitat consists of its chemical resources of the soil, water, and air as well as its physical conditions. List some of the aspects that make up the physical conditions of a habitat.
10
Ecosystems have living and non-living components
15.2 A variety of biomes occur around the world, each determined by temperature and rainfall.
11
15.2 A variety of biomes occur around the world, each determined by temperature and rainfall.• What is the average temperature?• What is the average rainfall (or other precipitation)?• Is the temperature relatively constant or does it vary
seasonally?• Is the rainfall relatively constant or does it vary
seasonally?
12
13
14
Tropical Rain Forest
• forest of tall trees in a region of year-round warmth• ~ 125 to 660 cm yearly rainfall• temperature ranges from 20 °C - 34 °C• average humidity 77 - 88%• rainfall > 250 cm/year (may be a brief dry season) • almost all rain forests lie near the equator
15
Tropical Rain Forest
• < 6% of Earth's land surface• > 50% of all the world's plant and animal species live in
tropical rain forests• produce ~40% of Earth's oxygen• ~70% of the plants in the rainforest are trees• ~25% of all the medicines we use come from rainforest
plants
16
Tropical Rain Forest
17
Indicator Species
• any biological species that defines a trait or characteristic of the environment• may delineate an ecoregion • could indicate an environmental condition such as
a disease outbreak, pollution, species competition or climate change
• can be among most sensitive species in a region; sometimes act as early warning to monitoring biologists
18
Tropical Rain Forest – Indicator Plant Species
19
Tropical Rain Forest – Indicator Animal SpeciesGorilla
Gorilla gorilla
Orangutan (Pongo pygmaeus)
Spider MonkeyAteles geoffreyi
20
Tropical Rain Forest – Indicator Animal Species2-toed sloth
Cholepus hoffmanni
Three-toed Sloth (Bradypus variegatus) with baby - Costa Rica
21
Tropical Rain Forest – Indicator Animal Species
Collared AracariPteroglossus torquatus
22
Grasslands (Prairie)
• 2 different types • tall-grass: humid & very wet• short-grass: dry; hotter summers and colder winters
than the tall-grass prairie• found in middle latitudes in the interiors of continents• either moist continental climates or dry subtropical
climates• Argentina - grasslands are known as pampas• grasslands in southern hemisphere tend to get more
precipitation than those in the northern hemisphere
23
Grasslands (Prairie)
24
Grasslands (Prairie)• temperatures range from -40° F 70° F• growing season and a dormant season
• growing season is when there is no frost and plants can grow (which lasts from 100 to 175 days)• tropical and subtropical grasslands the length of
the growing season is determined by how long the rainy season lasts
• temperate grasslands the length of the growing season is determined by temperature (≥ 50° F)
• dormant (not growing) season: nothing can grow because its too cold
25
Grasslands (Prairie)• average rainfall per year ranges from 10 - 30 inches
• tropical and sub-tropical grasslands: average rainfall per year ranges from 25 - 60 inches
• amount of rainfall is very important in determining which areas are grasslands • hard for trees to compete with grasses in places
where the uppers layers of soil are moist during part of the year but where deeper layer of soil are always dry.
26
Grasslands (Prairie)
27
Grasslands– Indicator Plant SpeciesOld Field Habitat, Ohio
Grassland, North Dakota
Ironweed (Vernonia sp.) with Hedge Bindweed
Vine (Calystegia sepium)
28
Grasslands– Indicator Plant Species
Ironweed (Vernonia sp.)
Joe Pye WeedEupatorium purpureum
29
Grasslands – Indicator Plant Species
Common TeaselDipsacus fullonum Queen Anne's Lace (Daucus carota)
30
Grasslands – Indicator Animal Species
Bison (Bison bison) on the range, Theodore Roosevelt National Park, North Dakota
31
Grasslands – Indicator Animal Species
Przewalski's horse (Equus caballus przewalskii), The Wilds, Ohio
32
Grasslands – Indicator Animal Species
33
Taiga• Russian word for forest • largest biome in the world• Eurasia, North America• located just below the tundra biome• many coniferous trees • aka boreal forest; Boreal was the Greek goddess of the
North Wind
34
Taiga• winter temperature range is -54 to -1° C (-65 to 30° F)• summer: -7° C (20° F) to 21° C (70° F)• summers are very short (50 - 100 frost free days) • average yearly precipitation: 30 - 85 cm (12 - 33 in)• main seasons are winter and summer
• spring and autumn are very short • weather is either hot and humid or very cold
35
Taiga
36
Taiga – Indicator Plant Species
Balsam FirAbies balsamea
Black SprucePicea mariana
37
Taiga – Indicator Plant Species
Jack PinePinus banksiana
Paper BirchBetula papyrifera
White PoplarPopulus alba
38
Taiga – Indicator Animal Species
American Black BearUrsus americanus
Bald EagleHaliaeetus leucocephalus
39
Taiga – Indicator Animal Species
Long-eared OwlAiso otus
Snowshoe RabbitLepus americanus
40
Desert• cover about one fifth of Earth's land surface
• hot and dry: near Tropic of Cancer/Tropic of Capricorn• cold: near the Arctic
• temperature• hot & dry: ~ 25° C to ~ 49° C• cold: -2 to 4° C (winter) 21 to 26° C (summer)
• precipitation • hot & dry: very little rainfall and/or concentrated
rainfall in short periods between long rainless periods (< 15 cm/year)
• cold: 15 - 26 cm/year
41
Desert
42
Desert – Indicator Plant Species
43
Desert – Indicator Plant Species
Saguaro Cactus Carnegiea gigantea
Fishhook Cactus Mammillaria microcarpa
44
Desert – Indicator Plant Species
Trichomes
45
Desert – Indicator Animal Species
Zebratail Lizard - Callisaurus draconides
46
Desert – Indicator Animal Species
Rock hyrax (Procavia capensis)
47
Desert – Indicator Animal Species
Bactrian Camel, Camelus bactrianus
48
Temperate Deciduous Forest
• temperature: 0 - 20 C• precipitation: ~ 50 – 200 cm/year
49
Temperate Deciduous Forest
50
Temperate Deciduous ForestIndicator Plant Species
Oaks (Quercus sp.)
Dutchman's-BreechesDicentra cucullaria
51
Temperate Deciduous ForestIndicator Plant Species
SassafrasSassafras albidum
RedbudCercis canadensis
52
Temperate Deciduous Forest – Succession• orderly succession of communities to a climax
community (biome)• two main types of succession:
• primary succession: begins with bare rock exposed by geologic activity
• secondary succession: begins on soil from which previous community has been removed (by fire, agriculture, etc.)• secondary succession can proceed much faster
because the soil has been prepared by the previous community
53
Temperate Deciduous ForestIndicator Animal Species
American ToadBufo americanus
Box Turtle
54
Temperate Deciduous ForestIndicator Animal Species
Eastern Chipmunk Tamias striatus
Eastern Gray SquirrelSciurus carolinensis
55
Temperate Deciduous ForestIndicator Animal Species
Yellow-breasted chatIcteria virens
56
Tundra• annual average temperature < 5 C• precipitation (mostly in the form of snow) < 100 mm/year• summer is brief
• temperatures above freezing last only a few weeks at most
• "warm" summer coincides with periods of almost 24 hour daylight, so plant growth can be explosive
57
Tundra
Anaktuvuk Pass, Alaska
58
Tundra – Indicator Plant Species
Arctic Tundra Wildflowers - Alaska
59
Tundra – Indicator Plant Species
Lichen
Polytrichum Moss(photographed in Ohio, not on the
Tundra)
60
Tundra – Indicator Animal Species
Reindeer Rangifer tarandus
61
Tundra – Indicator Animal Species
Caribou On Autumn Tundra Denali National Park Alaska
62
Savanna• rolling grassland scattered with shrubs and isolated trees
• found between a tropical rainforest and desert biome• not enough rain falls on a savanna to support forests• found in a wide band on either side of the equator on
the edges of tropical rainforests• warm temperature year round• very long dry season (winter): ~ 10 cm rain; none at all
from Dec - Feb• very wet season (summer): ~ 35-65 cm rain
63
Savanna
64
Savanna – Indicator Plant Species
BaobabAdansonia digitata
Umbrella Thorn AcaciaAcacia tortillis
65
Savanna – Indicator Animal Species
Savanna ElephantLoxodonta africana
Black MambaDendroaspis polylepis
LionPanthera leo
66
Chaparral• winter: mild and moist, but not rainy• summer: very hot and dry. • annual temperature range: between -1° and 38° C• annual precipitation: ~ 25-45 cm, mostly in the winter
67
Chaparral
68
Chaparral – Indicator Plant Species
Blue OakQuercus douglasii
Common SagebrushArtemisia tridentata
Olive TreeOlea europaea
69
Chaparral – Indicator Animal Species
Black-tailed JackrabbitLepus californicus
Golden JackalCanis aureus
Spotted SkunkSpilogale gracilis
70
The Freshwater Biome• low salt concentration — usually less than 1%• plants and animals in freshwater regions are adjusted to
the low salt content and would not be able to survive in areas of high salt concentration (i.e., ocean)
• 3 different types of freshwater regions:• ponds and lakes• streams and rivers• wetlands
71
The Freshwater Biome – Ponds and Lakes
From left: a view across Manzanita Lake toward Mt. Lassen, California; a forest pond near Donnelly, Idaho; a Great Blue Heron; Paranagat Lake, southeastern Nevada.
72
The Freshwater Biome – Streams and Rivers
From left: McArthur-Burney Falls State Park, California; trout; Green River, Utah; Brooks River, Alaska.
73
The Freshwater Biome - Wetlands
From left: Pescadero Marsh, California; coastal marsh at Umpqua Dunes, Oregon; trees and bogs on Esther Island, Alaska.
74
The Marine Biome• cover about three-fourths of the Earth's surface • marine algae supply much of the world's oxygen supply
and take in a huge amount of atmospheric carbon dioxide
• evaporation of the seawater provides rainwater for the land
• 3 different types of marine regions:• oceans• coral reefs• estuaries
75
The Marine Biome - Oceans
From left: mussels, worms, and a spider crab at a hydrocarbon seep community in the Gulf of Mexico; a sea fan and brain coral in the Florida Keys National Marine Sanctuary; a school of Atlantic amberjack off North Carolina.
76
The Marine Biome – Coral Reefs
From left: reef life in the Gulf of Aqaba, Red Sea; a reef at Fanning Island atoll in the central Pacific; a reef in the Florida Keys National Marine Sanctuary.
77
The Marine Biome - Estuaries
From left: Mangrove roots, south Florida; wetlands and tidal streams in the Ashe Island area, ACE Basin National Estuarine Research Reserve, South Carolina; a salt marsh in Winyah Bay National Estuarine Research Reserve, South Carolina.
78
Ecological Notes
These are the biomes, in order of their productivity (highest first)
1. estuaries and tropical rain forest (highest)2. temperate forest3. agricultural land4. temperate grassland5. lakes and streams6. coastal zone7. tundra8. open ocean9. desert (lowest)
79
Ecological Notes
In order to be productive and have a lot of living material standing around (biomass), an ecosystem has to have 4 basic necessities for plant life to thrive (if there are enough plants, the ecosystem will also support a lot of animals). The four things are:
1. Sunlight2. Nutrients3. Warm temperatures4. Water
81
Take-Home Message 15.2• Biomes are the major ecological communities of earth,
characterized mostly by the vegetation present. Different biomes result from differences in temperature and precipitation, and the extent to which they vary from season to season.
82
Challenge Question 15.2• Terrestrial biomes are determined by the temperature
and precipitation amounts as well as whether those factors are constant or vary by season. By contrast, how are aquatic biomes determined?
83
Physical forces interacting create weather
15.3 Global air circulation patterns create deserts and rain forests.
84
85
86
Water also cycles through ecosystems. It continually moves from the ocean to the air and land, then returns to the ocean in a cyclic pattern.
87
88
Take-Home Message 15.3• Global patterns of weather are largely determined by the
earth’s round shape. Solar energy hits the equator at a more direct angle than at the Poles, leading to warmer temperatures at lower latitudes. This temperature gradient generates atmospheric circulation patterns that result in heavy rain at the equator and many deserts at 30° latitude.
89
Challenge Question 15.3• Global weather patterns are mainly determined by the
amount of solar energy falling on an area. The amount of solar energy that falls on an area largely depends on the angle at which this light hits the earth. Explain what this means.
90
Physical forces interacting create weather
15.4 Local topography influences the weather.
91
15.4 Local topography influences the weather• High altitudes have lower temperatures
• With increasing elevation, the air pressure drops—this is because the weight of the atmosphere becomes lower as altitude increases.
• When pressure is lower, the temperature drops. For each 1000 meters above sea level, the temperature drops by about 6° C.
92
15.4 Local topography influences the weather
93
15.4 Local topography influences the weather
• Asphalt, cement, and tops of buildings absorb heat, raising the temperature.
• Tall buildings force wind downward.
94
15.4 Local topography influences the weather
Which place would you expect to have the highest temperature during the summer?
1. Denver, Colorado (the mile high city)2. Dallas, Texas (large city)3. Farmer’s Branch, Texas (small town outside of
Dallas)4. Freeport, Maine (small town)
95
Take-Home Message 15.4• Local features of topography influence the weather. With
higher altitude, the temperature drops. On the windward side of mountains, rainfall is high; on the backside, descending air reduces rainfall, causing rain shadow deserts. Urban development increases the absorption of solar energy, leading to higher temperatures, and creates wind near the bottom of tall buildings.
96
Challenge Question 15.4• A rain shadow is a dry region on the landward side of a
mountain range. How is it formed?
97
98
Physical forces interacting create weather
15.5 Ocean currents affect the weather.
15.5 Ocean currents affect the weather• water is continuously moving and mixing due to a
combination of forces • wind• earth’s rotation• gravitational pull of the moon• temperature• salt concentration
99
15.5 Ocean currents affect the weather
100
15.5 Ocean currents affect the weather• Why do beach communities have milder weather than
more inland communities?• Beaches on the east coast of the United States have
warmer water than west coast beaches at the same latitudes – why?
101
15.5 Ocean currents affect the weather
102
15.5 Ocean currents affect the weather
103
Water can affect the climate in which example below?
1. Ecosystems located near large bodies of water2. El Niño3. Temperatures in Europe compared to North America4. All of the above
104
Take-Home Message 15.5• Oceans have global circulation patterns. Disruptions in
these patterns occur every few years and can cause extreme climate disruptions around the world.
105
Challenge Question 15.5• Why is most of Europe significantly warmer than regions
in Canada at the same latitude?
106
107
Energy and chemicals flow within ecosystems
15.6 Energy flows from producers to consumers.
108
109
First Stop: Primary Producers
110
First Stop: Primary Producers• ecosystem: producers or consumers
• primary producers: plants, algae (some), bacteria • convert light energy from sun into chemical energy
through photosynthesis• chemical energy = food
• consumers eat or absorb their food• energy stored in chemical bonds of carbohydrate,
protein, and lipid molecules is captured and harnessed for consumers’ own movement, reproduction, and growth
111
Second Stop: Primary Consumers – the Herbivores
112
Third Stop: Secondary Consumers – the Carnivores
113
Fourth Stop: Tertiary Consumers – the “Top” Carnivores
114
Food Chain
115
Food Web
116
Food Web
117
Food Chains & Food Webs• A change in one link in a food chain will affect the other
links. • The table on the next slide gives one example of a food
chain and the trophic levels represented in it:
118
Food Chains & Food Webs
119
GRASS
GRASSHOPPER
TOAD
SNAKE
HAWK
BACTERIA
IN GENERAL,
AUTOTROPHS (PRODUCERS)
HERBIVORES(PRIMARY
CONSUMERS)
CARNIVORES(2, 3, ETC.)
DECOMPOSERS
120
Chain Reaction Game
121
Energy Flows through a Food Web• Losses at every “step” in a food chain
• Inefficiency of energy transfers
122
A grasshopper eats a plant. A mouse eats the grasshopper. A snake eats the mouse. A hawk could eat the snake or the mouse. In this food web, how would we categorize the hawk?
1. Producer2. Primary consumer3. Secondary consumer4. Tertiary consumer5. Quaternary consumer6. 4 and 5
123
Take-home message 15.6• Energy from the sun passes through an ecosystem in
several steps. • First, it is converted to chemical energy in
photosynthesis. • Herbivores then consume the primary producers, the
herbivores are consumed by carnivores, and the carnivores, in turn, may be consumed by top carnivores.
124
Take-home message 15.6• Detritivores and decomposers extract energy from
organic waste and the remains of organisms that have died.
• At each step in a food chain, some usable energy is lost as heat.
125
126
Energy and chemicals flow within ecosystems
15.7 Energy pyramids reveal the inefficiency of food chains.
Biomass• biomass: total weight of all living organisms in a given
area• only about 10% of the plants in an ecosystem is
converted into biomass• Food Energy Pyramid
• flow of energy through a food chain• trophic level: position that an organism occupies in a
food chain - what it eats, and what eats it• African savannas and grasslands sustain more species
of higher-order carnivores than any other terrestrial ecosystem
127
128
Food Energy Pyramids• flow of energy through a food chain• trophic level: position that an organism occupies in a
food chain - what it eats, and what eats it
129
130
131
You go out to eat at a fancy restaurant. You have a salad, salmon, and for dessert ice cream! Which part of the meal was the most energy efficient food for you to eat?
1. Salad 2. Salmon3. Ice cream 4. 2 and 3
132
Take-home message 15.7• Energy from the sun passes through an ecosystem in
several steps known as trophic levels. • Energy pyramids reveal that the biomass of primary
producers in an ecosystem tends to be far greater than the biomass of herbivores.
• The biomass transferred at each step along the food chain tends to be only about 10% of the biomass of the organisms being consumed, due to energy lost in cellular respiration.
• As a consequence of this inefficiency, food chains rarely exceed four levels.
133
134
Energy and chemicals flow within ecosystems
15.8 Essential chemicals cycle through ecosystems.
Chemical Reservoirs• Each chemical is stored in a non-living part of the
environment.
• Organisms acquire the chemical from the reservoir, a non-living part of the environment.
• The chemical cycles through the food chain (biogeochemical cycles).
• Eventually, the chemical is returned to the reservoir.
135
The Most Important Chemical Cycles
1) Carbon2) Nitrogen3) Phosphorus4) Sulfur
136
137
Fossil Fuels• created when large numbers of organisms die and are
buried in sediment lacking oxygen• In absence of oxygen, at high pressures, and after very
long periods of time, organic remains are ultimately transformed into coal, oil, and natural gas
• burning coal, oil, and natural gas releases large amounts of carbon dioxide• increases average CO2 concentration in the
atmosphere• current level of CO2 in the atmosphere is the highest it
has been in almost half a million years
139
Global CO2 levels are rising in general, but they also exhibit a sharp rise and fall within each year – why?
140
141
Fertilizers• Because it is necessary for the production of every plant
protein, and because all nitrogen must first be made usable by bacteria, plant growth is often limited by nitrogen levels in the soil.
• For this reason, most fertilizers contain nitrogen in a form usable by plants.
142
143
144
145
Sulfur Cycle• component of protein • cycles in both a gas and sedimentary cycle• source : earth's crust• enters the atmosphere as hydrogen sulfide (H2S)
during fossil fuel combustion, volcanic eruptions, gas exchange at ocean surfaces, decomposition
146
Sulfur Cycle• H2S is immediately oxidized to sulfur dioxide (SO2) • SO2 + water vapor H2SO4 (falls to earth in rain) • sulfur in soluble form is taken up by plant roots,
incorporated into amino acids such as cysteine• travels through food chain • eventually released through decomposition
147
How is carbon recycled back to the atmosphere in the carbon cycle?
1. It is “fixed” by bacteria.2. It is a product of cellular respiration.3. Burning of fossil fuels.4. 2 and 3.5. All of the above.
148
Why do commercial fertilizers usually contain usable forms of nitrogen and phosphorous?
1. These chemicals are not efficiently recycled in the soil.
2. Nitrogen and phosphorous need to be “fixed” by bacteria or the plant.
3. Nitrogen and phosphorous are found at high levels in the atmosphere but not in the soil.
4. Nitrogen and phosphorous only enter the soil through erosion.
149
Take-home message 15.8• Chemicals essential to life—including carbon,
nitrogen, and phosphorus—cycle through ecosystems.
• They are usually captured from the atmosphere, soil, or water by growing organisms; passed from one trophic level to the next as organisms eat other organisms; and returned to the environment through respiration, decomposition, and erosion.
• These cycles can be disrupted as human activities significantly increase the amounts of the chemicals utilized or released to the environment.
150
151
Species interactions influence the structure of communities.
15.9 Interacting species evolve together.
152
153
Natural Selection• Causes organisms to become better adapted to their
environment
• Does not distinguish between biotic and abiotic resources as selective forces
154
Coevolution• two (or more) species reciprocally affect each
other’s evolution• likely to happen when different species have
close ecological interactions with one another including:• predator/prey• parasite/host• competitive species• mutualistic species
155
156
Penicillin was first isolated from a fungus growing on a plate of bacteria. This is an example of an adaptation of the fungus to fight off the bacteria. This interaction could be described as:
1. coadaptation.2. coevolution.3. symbiosis.4. predation.
157
Take Home Message 15.9• In producing organisms better adapted to their
environment, natural selection does not distinguish between biotic and abiotic resources as selective forces.
158
159
Species interactions influence the structure of communities.
15.10 Each species’ role in a community is defined by its niche.
More than just a place for living, a niche is a complete way of living
160
More than just a place for living, a niche is a complete way of living• Fundamental niche: the full range of environmental
conditions under which a species can live
• Realized niche: where and how a species is actually living
161
Take Home Message 15.10• A population of organisms in a community fills a unique
niche, defined by the manner in which they utilize the resources in their environment.
• Organisms do not always completely fill their niche; competition with species that have overlapping niches can reduce their range.
162
163
Species interactions influence the structure of communities.
15.11 Competition can be hard to see, but it still influences community structure.
164
165
Why is competition hard to see in nature?
166
How can two very similar species avoid the consequences of competitive exclusion principle?
1. avoid predation 2. one species will become locally extinct 3. character displacement will occur 4. 2 and 3 5. all of the above
167
Take Home Message 15.11• Populations with completely overlapping niches cannot
coexist forever.
• Competition for resources occurs until one or both species evolve in ways that reduce the competition, through character displacement, or until one becomes extinct in that location.
168
169
Species interactions influence the structure of communities.
15.12 Predation produces adaptation in both predators and their prey.
Predation• interaction between two species in which one species
eats the other• one of most important forces shaping composition and
abundance of species in a community
170
Why do exotic species often flourish when released into novel habitats, even though natural selection has not adapted them to this new environment?
171
Prey Adaptations for Reducing Predation• physical
• mechanical• chemical• warning coloration• camouflage mechanisms
• behavioral• passive and active behaviors
• hiding • escaping• alarm calling• fighting back
172
173
1) Mechanical Defenses
174
2) Chemical Defenses
175
3) Warning Coloration
176
4) Camouflage
177
178
Predator adaptations for enhancing predation
179
• toxic-avoidance methods • sensory perception
• faster running ability
• mimicry
180
Why don’t predators become so efficient at capturing prey that they drive the prey to extinction?
181
• predator adaptations are rarely so efficient that prey are driven to extinction
• “escape ability” in prey is stronger than selection for “capture ability” in predator
• cost of losing is much higher for prey
The gazelle can change direction very quickly while being chased by a cheetah (fastest land animal). The gazelle uses which method of defense listed below?
1. Mechanical defense2. Camouflage3. Behavioral4. Warning Coloration5. Chemical defense
182
Take Home Message 15.12• Predators and their prey are in an evolutionary arms
race.
• As physical and behavioral features evolve in prey species to reduce their predation risk, predators develop more effective and efficient methods of predation.
• The coevolutionary process can result in brightly colored organisms, alarm calling, and many types of mimicry.
183
184
THANK YOU TO…• http://www.blueplanetbiomes.org• http://www.marietta.edu/~biol/biomes/biome_main.htm• http://www.ucmp.berkeley.edu/exhibits/biomes/• http://www.tburg.k12.ny.us/mcdonald/foodch1.htm• http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/
FoodChains.html• http://ic.galegroup.com/ic/scic/ReferenceDetailsPage/
ReferenceDetailsWindow?displayGroupName=Reference&disableHighlighting=false&prodId=SCIC&action=e&windowstate=normal&catId=&documentId=GALE%7CCV2644030753&mode=view&userGroupName=catholiccenhs&jsid=71a9d03928f7c22aa5cc70824a0bbc99