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110 Cards in this Set
- Front
- Back
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Mechanism of (Speciation) |
Formation of new kinds of organisms |
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The accumulation of genetic changes |
The underlying reason why different kinds of organisms emerge. These changes eventually add up to the point where members of related populations can no longer interbreed successfully. |
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What are the patterns of speciations? |
Allopatric speciation vs sympatric speciation |
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allopatric speciation |
Involves geographic separation (some barrier representing reproductive isolation) |
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allopatric speciation, what is cladogenesis (allos- other, patr- homeland) |
the branching/ splitting of a population into 2 or more species. Cladogenesis most often results from allopatric speciation. |
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Cladogenesis usually results from what type of speciation? |
Allopatric speciation |
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Allopatric speciation |
other than reproductive isolation, allopatric speciation can also occur when small population moves to a new location & must adapt to natural selection in the new environment. (natural selection can rapidly alter genetic composition) |
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What is adaptive radiation? |
It is the result of allopatric speciation, and it is when 1 species evolves into array of descendants that differ greatly in habitat, form, or behavior. |
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Sypmatric speciation (sym- with, together) |
Occurs when members of a species in 1 area diverge into 2 more more species, even when there are no geographic barriers to prevent gene flow |
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What type of organisms do we usually see undergo sympatric speciation? |
More common in plants than in animals |
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What are the mechanisms of sympatric speciation? |
1. Poloyploidy: the presence of more than 2 sets of chromosomes. Plants are much more tolerant of polyploidy than animals; this can occur through nondisjunction during meiosis (autopolyploidy) or when members of 2 species mate successfully (allopolyploidy) 2. adaptation to local environments: geographic regions vary, so some individuals might be sympatric but occopy different local environments & thus diverge from each other 3. Sexual Selection: strong sexual selection can lead to divergence w/n members of 1 population |
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Example of adaptation to local environment |
the 200+ species of cichlid fishes in Lake Tanganyika that evolved from a single ancerstor |
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What is taxonomy |
the science of describing, naming, & classifying living & extinct organisms |
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What is systematics? |
the study of biodiversity among both extinct and extant organisms |
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How does taxonomy reflect phylogeny? What does taxonomy reflects phylogeny mean? |
The way we name & classify and organism must demonstrate our current understanding of phylogeny (evolutionary history). Sometimes we need to move organism into another group or create a new group. |
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Why do we need a formal naming system in biology and who regulates it? |
1. Biodiversity 2. because of so much biodiversity, random names aren't helpful, the must be informative 3. vernacular names are too variable (Ex: gopher) Regulated by international biological associations |
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Who created the nomenclature? |
Developed by Carolus Linnaeus in mid-1700 |
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What are the key characteristics of nomenclature? |
1. hierarchical: (nested) system involving successive level 2. Latin or Latinized names: easier to communicate with other scientists 3. binomial (2-name) system: unique binomial for every species of organism. Binomials also known as 'scientific name' |
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What is each group at any level in Linnaeus' system of organization called? |
Taxon (plural: taxa) |
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What category was not part of Linnaeus' original system? |
Domain |
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Name the three domains. |
1. archaea 2. bacteria 3. eukarya Prokarya- bacteria or archaea |
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What are the taxa in hierarchy? (biggest to smallest) |
Domain, Kingdom, Phylum (plural: phyla), Class, Order, Family (usually -idae in animals, -aceae in plants), Genus (plural: genera) , Species Dear King Phillip Came Over For Good Sex |
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How do we write scientific names? |
Name of genus (first part) always capitalized, the specific epithet (second part) not named and never stands alone. Scientific name single noun. Both parts italicized |
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Describe the difference between weather and climate. |
Climate- How the atmosphere behaves over a long period of time Weather- what is the condition of the atmosphere right now or short period of time |
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Define ecology |
the study of interactions between organisms & of interactions between organisms & their environment |
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Ecology includes the study of both ___? |
biotic (interaction among living) & abiotic (interaction between living & nonliving organisms) interation. |
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The word ecology is bases on what Greek word root and what does it mean? |
Oikos, which means house. |
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Ecology is closely allied with what other types of studies? |
Biodiversity, evolution, & biogeography. |
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What is biogeography? |
The study of distribution of species & ecosystems in a geographic space |
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Ecology is studied at several different scales, name them in order. |
organism, population, community, ecosystem, biosphere |
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Phylogenetic tree is a what? |
A type of evolutionary tree |
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A phylogenetic tree is a model. What's a model? |
a model depicts hypotheses. |
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The study of phylogenies revealed that new species can be formed via what? |
1. anagenesis: 1 species evolve into another 2. cladogenesis: 1 species diverges into 2 or more species |
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Building a phylogenetic tree (anagenesis or cladogenesis) requires what? |
1. shared conservative characters (not primitive): two or more taxa share a trait inherited from ancestors older than their last common ancestor (trait held for a very, very long time). Ex: 4 limbs 2. shared derived characters (not advanced): two or more taxa share a trait inherited from their most recent common ancestor. Ex: human hair & mammory gland |
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What is the principle of parsimony |
Must be kept in mind for phylogenetic trees. States that the simplest explanation is most likely the correct one. |
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Biologists use what to determined phylogenetic relationships? |
Systematics to determine phylogenetic relationships. |
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Phylogenetic trees demonstrating phylogenetic relationships are usually based on what? |
Based on morphological &/or genetic data |
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How are some phylogenies determined? What is the name of this particular type of analysis? |
Cladistics, These analyses result in a particular type of phylogenetic tree called cladogram |
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Characteristics of cladogram: |
nodes (branching points): always dichotomous ingroup: the taxa being studied outgroup: a taxon you a know a priori don't belong in your group |
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Distributions & abundance of species are limited by what? |
physical features of the environment |
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List the 6 environmental events that effect the distrubution of organisms |
1. temperature 2. wind 3. water availability 4. light availability 5. salinity 6. pH |
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Describe why temperature effects distribution of organisms |
Temperature is the most important. 1. most organisms are unable to regulate body temperature (Tb) precisely, so they are impacted by environmental temperature |
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How does low temperature affect distribution? |
Low temperature can cause frost, which limits distributions of many species of plants (ex. cactus) Low temperature also limits distributions of endothermic animls (animals that regulat Tb using body heat) Ex. Eastern Phoebe |
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1. How does high temperature be limiting? and why? give an example |
Organisms unable to survive in high heat, Ex. protein and plasma membrane denature ex. corals |
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Is greenhouse effect man made? |
No |
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Describe how green house effect takes place and its importance. |
solar radiation passes through the atmosphere & strikes the earth's surface, thus warming the planet. some of this energy bounces off Earth (especially over water, sand and ice) back into the atmosphere. gases in the atmosphere re-direct this energy back to Earth, warming the planet still further Without greenhouse life would not exist |
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Name some greenhouse gases |
water vaper, CO2, methane, nitrous oxide, cholorofluorocarbons |
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Global warming |
increased global temperatures primarily by increasing CO2, because of humans |
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2. Wind, name the 5 reasons why wind affects the distribution of organisms |
(1)Wind can amplify effects of temperature, (2)increases heat loss by (i)evaporation (heat transfer through a layer of liquid, (ii)transpiration (the loss of H2O from interior of plants), (iii) convection (the transfer of heat from an object or an organism to the external evnironment) ex. radiation- not sweating/liquid (3)plants can be damaged or destroyed (4) intensifies ocean waves. some adaptations to withstand pounding waves include (seaweed use holdfast & animals use organic glue or muscular feet) |
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3. Water availability, name the two reasons how water availability affects distribution of organisms |
1. Some plants do well in flooded areas (swamps) and other do well in areas where little water is available (sand dunes) 2. animal distributions are linked to plants distribution. (ex. grass productivity in the Serengeti related to rainfall and water, buffalo density is governed by food availability) |
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4. Light availability, How does light availability effect distribution of organisms |
1. Necessary for photosynthesis 2. specific-specific (what might be enough light for one is not enough for another) 3. Water absorbs light, limiting photosynthesis to the photic (depths greater than 100m) zone. aphotic- too dark |
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5. Salinity, How does salinity effect distribution of organisms? How do marine birds and fish compensate for salt water |
1. freshwater fish vs saltwater fish. "freshwater" tend to gain water and must constantly excrete water. "saltwater/marine" lose water & must drink water to compensate. (salt excreted at gills and kidney. saltwater urine is concentrated and little 2. marine birds and reptiles have salt glands to get rid of salt |
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5. Salinity, what are the adaptations of halophytes include? |
include plants that tolerate higher salt and might have salt glands to excrete salt. "phyt" - always refers to plants |
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6. pH, what is the pH for slightly acidic rainwater and how is it caused? |
5.6, because of CO2 forming carbonic acid (H2CO3) |
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6. How does pH affect distribution? How does acidity affect fish? |
1. most plants grow best at pH 6.5 because nutrients are most available 2. acidity affects the activity of nitrifying bacteria (what does nitrifying bacteria do?) these bacteria give nitrogen. certain species of bacteria that have symbiotic relationships of root in certain plants. (acidity affect fish) fishes will decline, acidity causes mucus to cover gills, lowers ability to regulate salts, and affects bone formation |
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6. pH, What is acid rain and how does it affect plants? |
rain or snow with less than 5.6 pH. results from burning fossil fuel containing sulfur dioxide and nitrogen oxide. make rivers and lakes more acidic, affecting juvenile fish. directly affects forests by killing leaves or depressing soil of pH (essential nutrients are lost) |
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Define biome |
a geographic region containing communities composed of organisms with similar adaptations. communities- an area that contains populations of many different species |
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what are the 2 major factors that determine distributions of biomes? We recognize many terrestrial biomes by identifying what? |
temperature and precipitation by identifying dominant life form of plants (NOT animals) |
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Which of Earth's characteristics influence patterns of temperature and precipitation, thus affecting the distribution of biomes? and what is it driven by? |
atmospheric circulation. is driven by differences in global temperature. Earth is a sphere so differences in temperature are affected by how sunlight strikes Earth's surface. |
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How does sunlight strike the surface near the poles? How does sunlight strike areas near the equator? |
Differences in temperature due to latitudinal variations in solar radiation. in higher latitudes the sun's rays hit the Earth obliquely. Directly, he is intense. |
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Global patterns of atmospheric circulation and precipitation are influenced why what? |
solar energy |
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In 1753 who developed the model of atmospheric circulation? Describe the model |
George Hadley Heat at the equator causes air to rise, losing moisture as it does. Low-pressure areas occur wherever air is flowing upwards away from Earth's surface |
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What is the weather like in low-pressure areas and high-pressure areas |
low pressure zones- typically very dry because of lost moisture (no precipitation) high-pressure areas- typically moist and hot |
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Hadley did not fully take into account the effects of Earth's rotation. Rotation causes what? (and describe it) |
Coriolis Effect- the deflection of surface flow westward due to Earth's rotation. *Earth rotates toward East |
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Topography can result to what? Topography- the rising and falling of land masses |
Adiabatic cooling and rain shadows |
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Define adiabatic cooling and rain shadows |
adiabatic cooling: increasing elevation leads to 10*c drop for every 1000 meters (adiabatic heating- when you go down) rain shadow: warm, most air flows up mountain and releases precipitation. drier air flows down the leeside. (rainshadow refers to leeward side, aka desert area) |
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Proximity of a land mass to a large body of water- sea breezes and offshore breezes can effect temperatures on coasts because? |
seabreezes(cool daytime breezes in costal areas)- during day, land heats up and air rises, pulling cool ocean air to replace it. offshore breeze- at night, the land cools quicker than the sea and the pattern reverses |
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The Coriolis effect and atmospheric winds also drive major ocean currents. How do these currents affect temperature? |
the rotation of the Earth and winds also create ocean currents |
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Why was aquatic zone debated as a biome? |
No dominant life form of plants |
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Who developed the concept of biogeographic regions and explain what it is |
developed by Alfred Wallace. He divided the world's terrestrial biota into 6 major biogeographic region (Oceanic added later on) These regions are separated by (1) endemics and (2) bounded by major barriers to dispersal. (Ex. oceans around continents, Himalayas & sahara desert) |
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What is a population |
group of interbreeding individual occupying the same habitat at the same time interbreeding- produce viable, fertile offspring. habitat- group of abiotic condictions that organisms can live in |
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Population ecologists use the tool of what? Explain what it is |
demography- the study of statistics such as birth rates, death rates, age distributions, and sizes of populations. this data helps up decide organism management |
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What is a characteristic of a populations |
density, refers to the number of organisms in a given unit area or volume |
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What are some tools we use to calculate population density? |
estimated by counting or trapping organisms by using a quadrat (a 50cm x 50 cm square, good for small plant species) or line transects (a 100m string, good for trees, and certain animals) density and size (of animal populations) can be estimated by using the mark-recapture method. Done by catching and marking animals. (count and release the marked individuals, then sampling the population again and comparing ratios of marked and unmarked indivuals) |
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we can apply principles of demography to the study of populations of other species. An important demographic tool is what? |
the life table: an age-specific summary of the survival of a population. Females are only included. |
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Data on life tables include: |
age-specific fertility rate (mx): proportion of female offspring born to females of reproductive rate (ex. if 100 females produce 75 females, mx=0.75) age-specific survivorship rate (lx): use survivorship data to find proportion of individuals alive at start of any given age class lxmx: contribution of each age class to overall population growth |
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lxmx can be used to calculate what? Explain the equation |
future population size (N). (sum)lxmx-R0- net reproductive rate (total number of female offspring an average female is expected to produce during her lifetime). If R0-1 population is stable (Nt+1=NtR0) t: pop size at next generation = t:pop size now, 0 net reproductive rate |
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Data from life tables can be used to create what? |
survivorship curves, which demonstrate numbers of surviving individuals in each age class on a curve Type I: Most individuals die late in life Type II: Uniform rate of decline Type III: Huge decline in young |
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Two models are generally used to describe how populations grow. These are based on whether or not resources are limited: |
exponential growth: population grows continuously at an ever-increasing rate (unlimited resources) logistic growth: population starts by growing exponentially, but eventually growth decreases and N(population size) becomes relatively constant |
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Calculating per capita growth rate is necessary for which model(s)? |
both models |
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How quickly populations grow equation |
dN/dt=B-D birth(B) death(D) |
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rewrite the equation to show how quickly populations grow on a per capita basis, (b=per capita birth rate & d= per capita death rate). The per capita rate of increase (r) is represented as r=b-d |
dN/dT=bN-dN --> dN/dt=rN (N is population size) |
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Exponential growth: dN/dt=rN As the value of (r) increases, growth rate will what? Describe the exponential growth graph |
As value of r increases, growth rate will increase. When r > 0 population increasing. J-shaped curve The intrinsic rate of increase, rmax, occurs when r reaches its maximum value. growth depends on both N & r, so the rate of increase is even greater as time passes. |
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When might you see exponential growth in nature? |
Bacteria or cancer. Or if population has been removed from an area, ex. elk all killed and reintroduced |
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Logistic growth: describe the graph dN/dt=rN (K-N)/K What is carrying capacity? |
Growth slows as N approaches K (carrying capacity) Carrying capacity (K) is the upper boundary for N. Carrying capacity is the max # of individuals that a particular area can support w/o habitat degradation. The value of K varies across time and space. (competition w/n species can be breater than between species) |
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Species interactions: What is amensalism |
Impact on 1 species, no impact on the other (ex. elephant steps on ant) |
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Species interactions: what is competition |
impact on both species |
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Species interactions: What is predation, herbivory, parasitism, & parasitoidism? What are parasitoids? |
negative impact on 1 species, and positive for the other parasitoids are organisms (like wasp) that take advantage of host at cost of host's life. Parasitoids are a mix of parasite and predators. |
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species interactions: What is mutualism? |
positive relationship for both species |
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species interactions: what is commensalism? mutualism and commensalism can contribute to what? |
Positive for 1 species, no impact on the other. Can contribute to population growth of the species involved. |
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How does competition affect growth? |
Competition can negatively affect growth of competing species. Ex. Gause (biologist) work with Paramecium- (caudatum, aurelia, and bursaria) Caudatum and aurelia grown together- caudatum went extinct. caudatum and bursaria- neither went extinct. |
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Gause (biologist) concluded that species with same requirements cannot live together in same place using same resources. That is, they cannot occupy same niche. What is niche? |
the range of abiotic and biotic conditions that can be tolerated by an organism. (range of abiotic and biotic conditions that species require) |
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results from Gause experiment and others, lead to competitive exclusion princple, which states? |
complete competitors cannot coexist |
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Similar species can co-exist through resource partitioning, which is?
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differentiation of niches, both in space and time, that enables species to coexist. Ex. birds partition part of the tree |
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What organisms shows higher degree of competition? Is competition common? |
Plants showed higher degree. However, marine organism tend to compete more than terrestrial ones. marine species are intertidal yes |
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Organisms have evolved many defenses against natural enemies, provide some example. |
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predators have major effects on what? this concept is supported strongly by what? Give two examples |
Prey population. the effects of invasive species. (where predators in new habitat where they themselves lack predators) burmese pythons in the Everglades (Florida) and introduction of chestnut blight. |
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Two examples of organisms that have evolved defenses against natural enemies |
structural defense-barbed quills of the porcupine. chemical defense- skunks. behavioral defenses |
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density-dependent and density-independent limit population growth. Describe density- dependent factors: |
Factors affect population size in relation to the populations density. These include: predation, parasitism, parasitoidism, and competition. detected by plotting mortality against density and finding a positive slope |
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describe density independent factors and what it includes. |
factors limit population size regardless of the population's density.
common density-independent factors include natural disasters: tornadoes, hurricanes, floods, and fires. detected by plotting mortality and finding zero slope. |
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inverse density-dependent factors: |
regulators of population size in the opposite direction as density increase or decrease |
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Human growth fits what type of population growth? The development of what let to this pattern? |
Human growth fits an exponential pattern since the development of agriculture and animal domestication. (1750-2012, population explosion because of medical technology and clean water) |
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Differences in age structure is what? what can it help predit? |
relative # of individuals in each defined age group. it can help predict the population growht of people in different areas. |
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Age structures are often depicted as what? |
population pyramids |
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Future growth rates can be difficult to predict because of what? |
differences in total fertility rates (TFR). TFR have decreased in many areas since 2005 due to senescence. |
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What does TFR refer to? |
the average # of live births a woman has in a life time |
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A TFR of what is needed for zero population growth? |
2.3 |
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The size of populations and how those populations use resources determine what? |
the ecological footprint of different countries. |
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what is ecological footprint? |
the aggregate total of productive land needed for survival in a sustainable world |
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which country has the largest ecological footpring? |
U.S. (avg.= 3 hecatares) |
