Ecology: The Study of Interactions Between Organisms and Their Environment
what determines where a species live & migrate?
strong effects :
- the climate (temperature, precipitation) → terrestrial organisms
- light & nutrient availability → aquatic organism
dispersal (too crowded can cause limited resources) & interactions (prey-predator) among organisms also affect where species live
what is ecology?
ecology = scientific study of the interactions between organisms and the living and nonliving components of their environment (temperature, sunlight, etc) → a science of relationships
- these interactions determine the distribution of organisms & their abundance
- ecologists ask research questions at different levels in biological hierarchy—individual, population, etc
scope of ecological research
visual
organismal
organism’s structure, physiology, and behavior meet the challenges of the environment
physiological, evolutionary, and behavioral ecology
eg : mating patterns
population
📌 population = group of individuals of the same species living in an area
population ecology analyzes factors affecting population size and why it changes over time
eg : what environmental factors affect the reproductive rate of flamingos?
community
📌 community = a group of populations of different species in an area
community ecology examines the affect of interspecific interactions on community structure and organization
eg : what factors influence the diversity of species that interact at an African lake?
ecosystem
📌 ecosystem = community of organisms in an area and the physical factors with which they interact
ecosystem ecology emphasizes energy flow and chemical cycling between organisms and the environment
eg : What factors control photosynthetic productivity in an aquatic ecosystem?
landscape
📌 landscape (or seascape) = mosaic of connected ecosystems
landscape ecology focuses on the exchanges of energy, materials, and organisms across multiple ecosystems
eg : To what extent do nutrients from terrestrial ecosystems affect organisms in a lake?
global
📌 biosphere = earth, global ecosystem—the sum of all the planet’s ecosystems and landscapes
global ecology examines how the exchange of energy and materials influences the function and distribution of organisms across the biosphere
eg : How do global patterns of air circulation affect the distribution of organisms?
global climate
weather vs climate
intro
earth’s climate varies latitude and season and is changing rapidly
climate = most significant influence on the distribution of organisms on land
the long-term prevailing weather conditions in an area constitute its climate
4 major physical components of climate = temperature, precipitation (humidity), sunlight, and wind
seasonality
seasonality in middle to high latitudes is caused by the tilt of Earth’s axis of rotation and its annual passage around the sun
seasonal variations in day length, solar radiation, and temperature increase steadily toward the poles
seasonal variation in sunlight intensities
The changing angle of the sun over the course of the year affects local environments
- eg : belts of wet and dry air on either side of the equator shift as the angle of the sun changes
- this causes wet and dry seasons at 20ºN and 20ºS latitudes, where tropical deciduous forests grow
seasonal changes in wind patterns alter ocean currents
- can cause upwelling of cold, nutrient-rich water from deep ocean layers
- influx of nutrients to surface waters stimulates population growth of phytoplankton and the organisms that feed on them
factors that affect global climate patterns
determined largely by solar energy & earth’s movement in space
causes latitudinal variations in climate
factors
temperature
the warming effect of the sun establishes temperature variations, circulation of air and water, and evaporation of water
angle of sunlight
the angle affects its intensity, amount of heat & light per unit of surface area
global air circulation & precipitation patterns
visuals
global air circulation and precipitation patterns
global wind patterns
- global air circulation and precipitation patterns play major roles in determining climate patterns
- intense sunlight causes water to evaporate in the tropics, and warm, wet air masses rise and flow from the tropics toward the poles
- rising air masses release water and cause high precipitation, especially in the tropics
- dry, descending air masses create arid climates, especially near 30º north and south
- air masses rise again at 60º north and south, and release abundant precipitation
- cold, dry rising air flows to the poles and descends, absorbing moisture and creating dry, cold climate at polar regions
eg : in the forest, it feels cool because the sunlight will cause evaporation of water which does not make the environment hot
regional & local effects on climate
climate varies seasonally and is modified by other factors including large bodies of water and mountain ranges
bodies of water
ocean currents influence the climate of nearby terrestrial environments by heating or cooling overlying air masses that pass over land
currents flowing toward the equator carry cold water from the poles; currents flowing away from the equator carry warm water toward the poles
due to the circulation, the temperature is constant (no seasons on the equator)
large bodies of water moderate the climate of nearby land due to the high specific heat of water (angin darat & laut)
- during the day, air rises over warm land and draws a cool breeze from the water across the land
- at night, the land cools, and air now rises over the warmer water and draws cool air off the land, replacing it with warmer air from offshore
mountains
mountains influence airflow over land and affect the climate in surrounding areas
- warm, moist air cools as it rises up a mountain and releases moisture on the windward side
- cool, dry air absorbs moisture as it descends on the leeward side, creating a “rain shadow” or sometimes causes the Foehn Wind
many deserts are found in the rain shadows of mountains
mountains also affect the amount of sunlight reaching an area
- in the Northern Hemisphere, south-facing slopes are warmer and drier because they receive more sunlight than north-facing slopes
- every 1,000 m increase in elevation produces a temperature drop of approximately 6ºC
vegetation
Terrestrial organisms, particularly forests, can alter climate at local and regional scales
The darker color of forests cause them to absorb more solar energy than deserts or grasslands
This warming effect is offset by transpiration, which causes evaporative cooling, which reduces surface temperatures and increases precipitation rates (solar energy won’t be felt)
The climate becomes hotter and drier in areas where humans have cut down large forests
Where humans have restored large forests, the climate becomes cooler and wetter
microclimate
📌 microclimate = very fine, localized patterns in climate
many features of the environment influence surrounding areas by casting shade, altering evaporation from soil, or changing wind patterns
eg : forest trees moderate the microclimate below them
environments are characterized by differences in :
- abiotic/nonliving factors : temperature, light, water, nutrients
- **biotic/**living factors : other organisms that are part of an individual’s environment
all also influence the distribution and abundance of life on Earth
global climate change
The burning of fossil fuels and deforestation have increased the concentration of greenhouse gases in the atmosphere
consequence :
global warming
a directional change to the global climate lasting three decades or more
Earth has warmed an average of 0.9°C (1.6°F) since 1900 and is projected to warm 1–6°C (2–11°F) more by the year 2100
Wind and precipitation patterns are shifting, and extreme weather events are occurring more frequently
migration
= the geographic ranges of hundreds of organisms
Movement of organisms to new geographic areas can harm the organisms already living there
Species with poor dispersal or a shortage of suitable habitat may reduce their range or become extinct
eg : the geographic ranges of 67 bumblebee species in the Northern Hemisphere have decreased
Studies of response to change since the last ice age help predict effects of future global climate change
Many tree species expanded northward following climate warming and glacial retreat
Some responded rapidly, others lagged behind the change in suitable habitat by several thousand years
Determining the location of suitable habitat under different climate scenarios can help predict future range shifts
Studying the response of particular species to such shifts in the past can help determine if they will keep pace with shifting climates in the future
if the temperature increases, the north part might be less hot so they can migrate there
biomes
📌 biomes = major life zones characterized by vegetation type (terrestrial biomes) or physical environment (aquatic biomes)
terrestrial biomes
general features
Terrestrial biomes are named for major physical or climatic features and predominant vegetation
- usually grade into each other without sharp boundaries
- the area of intergradation, called an ecotone, may be wide or narrow
Vertical layering of vegetation provides diverse habitats for animals in terrestrial biomes
- In a forest, vertical layering may consist of an upper canopy, low tree layer, shrub understory, herbaceous plants, forest floor, and root layer
The species composition of each kind of biome varies from one location to another
Similar characteristics can arise in distant biomes through convergent evolution
eg : cacti in North and South America and euphorbs in African deserts appear similar but arise from different evolutionary lineages
the distribution of terrestrial biomes is controlled by climate and disturbance
impact of climate
climate is a major factor in determining the locations of terrestrial biomes because it strongly influences the distribution of plants
climograph = plots the annual mean temperature and precipitation in a region
biomes are affected not just by mean temperature and precipitation, but also by the pattern of temperature and precipitation through the year
impact of disturbance
📌 Disturbance =event such as a storm, fire, or human activity that changes a community
example
- frequent fires can kill woody plants and maintain the characteristic vegetation of a savanna
- hurricanes create openings in forest canopies that allow different species to grow
In many biomes, even dominant plants depend on periodic disturbance
- Terrestrial biomes can be described by their distribution, precipitation, temperature, and the plants and animals that inhabit them
- Humans have altered much of Earth’s surface, and have important impacts on most terrestrial biomes
types
9 types
tropical forest
Occurs in equatorial and subequatorial regions
In tropical rain forests, rainfall is relatively constant, about 200–400 cm annually
In tropical dry forests, precipitation is seasonal, about 150 200 cm annually with a long dry season
Temperature is high year-round (25–29ºC) with little seasonal variation
Tropical rain forests are dominated by broadleaf evergreen trees; tropical dry forests are dominated by deciduous trees
Tropical forests are vertically layered and competition for light is intense
Animal diversity is higher in tropical forests than any other terrestrial biome
The major human impact on tropical forests is deforestation
Forested land is converted to farmland, urban areas, and other types of land use
deserts
- Deserts occur in bands near 30º north and south of the equator and in the interior of continents
- Precipitation is low and highly variable, generally less than 30 cm per year
- Desert temperature varies seasonally and daily
- Maximum temperature in hot deserts can exceed 50°C; in cold deserts it may fall below –30°C
- Desert plants are adapted for heat and desiccation tolerance, water storage, and reduced leaf surface area; many have $C_4$ or CAM photosynthesis
Plants have physical defenses, such as spines, and chemical defenses, such as toxins, to prevent feeding by animals
Many desert animals are nocturnal, and have adaptations for water conservation
Humans have reduced biodiversity in deserts through urbanization and irrigated agriculture
savanna
Occurs in equatorial and subequatorial regions
Precipitation is seasonal (average 30–50 cm per year) with dry seasons lasting eight to nine months
Savanna is warm year-round, with annual temperature averages 24–29ºC, but is more seasonally variable than in the tropical forests
Dominant plant species, including grasses and forbs, are fire-adapted and tolerant of seasonal drought
Large herbivores such as wildebeests and zebras are common, but insects are the dominant herbivores
Human-induced fires help maintain the savanna, but cattle ranching and overhunting threaten large-mammal populations
chaparral
Chaparral occurs in midlatitude coastal regions on several continents
Precipitation is highly seasonal with rainy winters and dry summers, annual average about 30–50 cm
Summer is hot (30–40ºC); fall, winter, and spring are cool (10–12ºC)
Chaparral is dominated by shrubs, small trees, grasses, and herbs; many plants are adapted to fire and drought
Animals include amphibians, birds and other reptiles, insects, browsing mammals, and a diversity of small mammals
Humans have reduced chaparral areas through agriculture and urbanization
temperate grassland
Temperate grasslands are found on many continents
Precipitation is highly seasonal with dry winters and wet summers
Annual precipitation averages 30–100 cm; periodic drought is common
Winters are cold, often below –10ºC, whereas summers are hot, often near 30ºC
The dominant plants, grasses and forbs, are adapted to droughts and fire
Mammals include grazers, such as bison and wild horses, and small burrowers, such as prairie dogs
Most grassland in North America and Eurasia has been converted to agricultural land
Drier grasslands have been transformed to desert due to the activity of grazers, such as cattle
coniferous forest/taiga
spans northern North America and Eurasia and is the largest terrestrial biome on Earth
Annual precipitation is 30–70 cm, and periodic drought is common
Coastal coniferous forests are temperate rain forests that may receive over 300 cm of annual precipitation
Winters are usually cold, while summers may be hot
- For example, coniferous forest in Siberia ranges from –50ºC in winter to over 20ºC in summer
The dominant vegetation includes evergreen conifers such as pine, spruce, fir, and hemlock
The conical shape of the trees is an adaptation to reduced branch breakage due to snow accumulation
Needle- or scale-like leaves reduce water loss
Animals include migratory and resident birds and large mammals such as moose, brown bears, and Siberian tigers
Periodic insect outbreaks kill vast areas of forest
Humans are logging old-growth stands at such a rapid rate that they may soon disappear
temperate broadleaf forest
Occurs primarily at midlatitudes in the Northern Hemisphere, with smaller areas in Chile, South Africa, Australia, and New Zealand
Significant amounts of precipitation fall during all seasons as rain or snow; annual precipitation varies from 70 to over 200 cm
Winter temperatures average 0ºC; summers are hot and humid with temperatures up to 35ºC
A mature temperate broadleaf forest has vertical layers, including a closed canopy, understory trees, a shrub layer, and an herb layer
- The dominant plants are deciduous trees in the Northern Hemisphere and evergreen eucalyptus in Australia
- Mammals, birds, and insects make use of all vertical layers in the forest
- In the Northern Hemisphere, many mammals hibernate and many birds migrate in the winter
- These forests have been heavily settled by human populations on all continents but are returning over much of their former range
tundra
Tundra covers expansive areas of the Arctic; alpine tundra exists on high mountaintops at all latitudes
Annual precipitation is lower in arctic tundra (20–60 cm) than alpine tundra (>100 cm)
Winters are cold, with averages below –30ºC; summers generally average less than 10ºC
Vegetation is mostly herbaceous, including mosses, grasses, forbs, dwarf shrubs and trees, and lichens
Permafrost, a permanently frozen layer of soil, restricts the growth of plant roots
Mammals include musk oxen, caribou, reindeer, bears, wolves, and foxes
Many migratory birds have summer nesting ground in the tundra
Human settlement is sparse, but tundra has become the focus of oil and mineral extraction
aquatic biomes
diverse & dynamic systems that covers most of earth
Aquatic biomes have less latitudinal variation than terrestrial biomes
They are characterized by their physical and chemical environment
eg : the average salt concentration in marine biomes is 3%, whereas in freshwater biomes it is less than 0.1%
Oceans have a major impact on the biosphere because they cover about 75% of the Earth’s surface
- Water evaporated from the oceans provides most of the planet’s rainfall
- Photosynthetic marine organisms provide most of the planet’s O2 and consume large amounts of CO2
- Ocean temperatures effect global climate and wind patterns, and moderate the climate of nearby land
Freshwater biomes are strongly influenced by the soil and biotic components of the surrounding terrestrial biome
The pattern and speed of water flow, and climate are also important factors affecting freshwater biomes
zonation
zonation in aquatic biomes
Many aquatic biomes are stratified into zones defined by light penetration, temperature, and depth
The upper photic zone has sufficient light for photosynthesis; the lower aphotic zone receives little light
The photic and aphotic zones make up the pelagic zone
The abyssal zone is located in the aphotic zone with a depth of 2,000–6,000 m
The organic and inorganic sediment at the bottom of all aquatic zones is called the benthic zone
The communities of organisms in the benthic zone are collectively called the benthos
Detritus, dead organic matter, falls from the surface and forms an important food source for the benthos
In oceans and most lakes, a temperature boundary called the thermocline separates the warm upper layer from the cold deeper water
Many lakes undergo mixing of their waters called turnover in the spring and autumn
Turnover sends oxygenated water from the surface to the bottom and nutrient-rich water from the bottom to the surface
Seasonal turnover in lakes with winter ice cover
Communities in aquatic biomes vary with depth, light penetration, distance from shore, and location in open water or near the bottom
In marine communities, most organisms occur in the relatively shallow photic zone
The aphotic zone in oceans is extensive but harbors little life
Aquatic biomes can be described by their physical and chemical environments, geologic features, photosynthetic organisms, and heterotrophs
Aquatic biomes are also impacted by human activities
types
lakes
Size varies from small ponds of a few square meters to very large lakes of thousands of square kilometers
Temperate lakes may have a seasonal thermocline; tropical lowland lakes have a year-round thermocline
Salinity, O2 concentration, and nutrient content vary among lakes and between seasons
Oligotrophic lakes are nutrient-poor and O2-rich with low organic content in sediments
Eutrophic lakes are nutrient-rich and high in organic content in sediments; O2 is periodically depleted in deeper layers due to high rates of decomposition
Oligotrophic lakes have less surface area relative to depth than eutrophic lakes
- Rooted and floating aquatic plants live in the shallow, well-lit littoral zone close to shore
- Phytoplankton inhabit the limnetic zone, where the water is too deep to support rooted plants
- Zooplankton are drifting heterotrophs that graze on the phytoplankton
- Invertebrates live in the benthic zone
- Fishes live in all zones with sufficient oxygen
- Human-induced nutrient enrichment can lead to algal “blooms,” oxygen depletion, and fish kills
wetlands
Wetlands are inundated by water at least some of the time and support plants adapted to water-saturated soil
Rapid organic production and decomposition periodically deplete dissolved oxygen
Wetlands develop in shallow basins, along flooded river banks, or on the coasts of large lakes and seas
Wetlands are among the most productive biomes
Plants include lilies, cattails, sedges, bald cypress, and black spruce
Woody plants are dominant in swamps, while bogs are dominated by sphagnum mosses
Wetlands are home to diverse invertebrates and birds, as well as otters, frogs, and alligators
Draining and filling by humans has destroyed up to 90% of wetlands in Europe
Wetlands help to purify water and reduce flooding
streams & rivers
The most prominent physical characteristic of streams and rivers is current
Headwater streams are usually cold, clear, swift, and turbulent; downstream rivers are warm and turbid
Salt and nutrient content of streams and rivers increases from the headwaters to the mouth
Streams and rivers are generally O2-rich, but organic enrichment can deplete O2 downstream
Headwater streams are often narrow with rocky bottoms; downstream rivers are generally wide and meandering with silty bottoms
Headwater streams may be rich in phytoplankton or rooted aquatic plants
A diversity of fishes and invertebrates inhabit unpolluted rivers and streams
Pollution degrades water quality and kills aquatic organisms
Damming and flood control impair natural functioning of stream and river ecosystems
estuaries
An estuary is a nutrient rich and productive transition zone between a river and the sea
Salinity varies spatially—from nearly fresh water to that of seawater—and with the changing tides
Estuaries include a complex network of tidal channels, islands, natural levees, and mudflats
Saltmarsh grasses and algae are the major producers
Invertebrates, fish, waterfowl, and marine mammals are abundant
Filling, dredging, and pollution upstream have disrupted estuaries worldwide
intertidal zones
An intertidal zone is periodically submerged and exposed by the tides
Upper intertidal zones experience longer exposure to air and greater variation in temperature and salinity
Physical differences between intertidal zones limit the organisms to particular strata
Oxygen and nutrient levels are generally high in intertidal zones
Substrates are generally either rocky or sandy
The configuration of bays or coastlines influence the magnitude of tides and mechanical forces of waves
Sandy intertidal zones tend not to have attached plants or algae, unless protected from vigorous waves in bays or lagoons
Rocky intertidal zones support attached algae; protected sandy zones support seagrass and algae
In rocky zones, many animals have structural adaptations for attaching to the hard substrate
In sandy zones, worms, clams, and crustaceans bury themselves in sand
Other animals include sponges, sea anemones, echinoderms, and small fishes
Oil pollution has disrupted many intertidal areas
Construction of rock walls and barriers to reduce erosion from waves also disrupts the intertidal zone
oceanic pelagic zone
The oceanic pelagic zone is an expanse of open water covering approximately 70% of Earth’s surface
- It is constantly mixed by wind-driven oceanic currents
- Oxygen levels are generally high, but nutrient concentrations are lower than coastal waters
- In temperate oceans, seasonal turnover renews nutrients in the photic zone
- Nutrient concentrations are lower in tropical oceans due to year-round thermal stratification
Phytoplankton and zooplankton are the dominant organisms
Phytoplankton in this zone account for about half of the photosynthesis on Earth
Fish, squid, turtles, and marine mammals are common
Overfishing, pollution, ocean acidification, and global warming have all harmed this biome
coral reefs
Coral reefs are formed from the calcium carbonate skeletons of corals
Shallow reef-building corals live in the photic zone in warm (about 18–30ºC), clear water; deep-sea corals live at depths of 200–1,500 m
Corals require high oxygen concentrations and a solid substrate for attachment
A coral reef progresses from a fringing reef to a barrier reef to a coral atoll
Corals form a mutualistic relationship with unicellular algae, which provide them with organic molecules
In addition to corals, other invertebrates and fish are also exceptionally diverse
Collection of coral skeletons, overfishing, global warming, pollution, and aquaculture are threats to coral reef ecosystems
marine benthic zone
The marine benthic zone consists of the seafloor below the surface waters of the coastal, or neritic, zone and the offshore pelagic zone
- Organisms in the very deep benthic (abyssal) zone are adapted to continuous cold (about 3°C) and very high water pressure
- Oxygen is typically abundant enough to support diverse animal life
- Soft sediments or rocks can form the substrate
- Photosynthetic organisms, seaweeds and filamentous algae, are restricted to shallow areas
- Deep-sea hydrothermal vents are found on mid-oceanic ridges
Chemoautotrophic prokaryotes are the food producers surrounding hydrothermal vents
Giant tube worms, echinoderms, and arthropods live around the hydrothermal vents
Neritic benthic communities include invertebrates and fishes
Overfishing and dumping of waste have depleted fish populations
species distribution
interactions between organisms and the environment limit the distribution of species
Species distributions are the result of ecological factors and evolutionary history
For example, kangaroos occur only in Australia, in part because the lineage originated there when the continent was geographically isolated
Ecological factors also affect the kangaroo distribution; particular species occur in some habitats, but not others
Both biotic and abiotic factors influence species distribution
For example, temperature and water availability are abiotic factors limiting the distribution of the saguaro cactus in North America
Interactions with herbivores, pollinators, and pathogens also limit the distribution of this cactus
ecologist’s train of thought
Ecologists explain the distribution of species by asking a series of questions about possible factors limiting distribution
dispersal
Dispersal is the movement of individuals or gametes away from their area of origin or centers of high population density
Dispersal contributes to the global distribution of organisms
natural range expansions & adaptive radiation
Natural range expansions show the influence of dispersal on distribution
For example, cattle egrets dispersed to South America from Africa in the late 1800s and have since expanded their distribution into Central and North America
In rare cases, long-distance dispersal can lead to adaptive radiation, the rapid evolution of an ancestral species into many ecologically diverse species
For example, Hawaiian silverswords are a diverse group descended from an ancestral North American tarweed
species transplants
Species transplants are used to determine if dispersal is key factor limiting distribution
They involve the intentional or accidental relocation of organisms from their original distribution
A successful transplant indicates that the potential range of a species is larger than its actual range
Species transplants can disrupt the communities or ecosystems to which they have been introduced
abiotic & biotic factors
biotic
In addition to predation and herbivory, other biotic factors may limit the distribution of species
- Presence or absence of pollinators
- Food resources
- Parasites and pathogens
- Competing organisms
abiotic
temperature
Environmental temperature has an important impact on many biological processes
For example, cells may freeze and rupture below 0ºC, while most proteins denature above 45ºC
Most organisms function best within a specific temperature range
Mammals and birds expend energy to regulate their internal temperature within that range
Range shifts in response to climate change can dramatically affect the distribution of other species
For example, the long-spined sea urchin (C. rodgersii) expanded its range in response to increasing water temperature
C. rodgersii consumed the seaweed in its new range and destroyed the diverse communities that formerly inhabited the seaweed stands
water & oxygen
Water availability in habitats is another important factor in species distribution
Desert organisms exhibit adaptations for water conservation
Water affects oxygen availability in aquatic environments, as oxygen diffuses slowly in water
Oxygen concentrations can be very low in deep ocean and deep lake waters
Sediments high in organic matter and flooded wetland soils are also low in oxygen
Surface waters of rivers and streams are well oxygenated due to rapid gas exchange with the atmosphere
salinity
Salt concentration affects the water balance of organisms through osmosis
Most terrestrial organisms excrete salt from specialized glands or in feces or urine
Few are adapted to high-salinity habitats
Most aquatic organisms are restricted to either freshwater or saltwater habitats by limited ability to osmoregulate
Salmon are able to migrate between freshwater and marine habitats by adjusting their water intake and switching gills from taking up to excreting salt
sunlight
Lack of sunlight can limit the distribution of photosynthetic species
Shading by leaves makes competition for light intense on the forest floor
In aquatic environments most photosynthesis occurs near the surface because water absorbs light
Too much light can also limit survival of organisms
In deserts, high light levels increase temperature and can stress plants and animals
At high elevations, the atmosphere is thinner and absorbs less of the harmful ultraviolet (UV) radiation
Damage from UV radiation combined with other stressors limits tree growth above a certain elevation
rock & soil
The pH, mineral composition, and physical structure of rocks and soil limit the distribution of plants and the animals that feed on them
The soil pH can limit distribution directly due to extreme acid or basic soil conditions or indirectly by affecting the solubility of toxins and nutrients
The substrate of rivers can affect water chemistry
In freshwater and marine environments, the structure of the substrate determines which organisms can burrow into or attach on to it
ecological change can cause evolutionary change
Ecological interactions can cause evolutionary change, and vice versa
For example, the diversification of plants on land provided new habitats and food sources for animals
In turn, new habitats and food sources stimulated bursts of speciation in an animals, leading to further ecological change
Ecological change and evolution have the potential to exert rapid feedback effects on each other
For example, color patterns, jaw morphology and feeding preference evolve rapidly in Trinidadian guppies when predators are removed
Guppies that evolved under different levels of predation have contrasting effects on algal abundance
