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93 Cards in this Set
- Front
- Back
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Biosphere
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Largest category, all ecosystems
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Density and Distribution
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Number of individuals in some specified area
-clumped -random -uniform distribution |
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Causes of population size change
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• Birth
• Death • Immigration • Emigration |
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Zero Population Growth
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Birth rate= Death rate, also immigration rate=emigration rate
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Population Growth rate
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• # of births / time interval
• total # present o net reproduction means birth and death together o use r to calculate pop growth rates |
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Biotic Potential
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o The maximum rate of increase under ideal condition
• rmax or intrinsic rate of increase |
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Exponential growth
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• dN/dt=rmax N
o dN/dT= Growth |
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Logistic Growth
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Growth that follows an S curve and levels off at the carrying capacity
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Carrying Capacity
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The max # that can be sustained in a given habitat
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Limiting factors
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lead a population towards carrying capacity
• An essential resource in short supply o availability of resources o predators o space- high density o competitors |
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Territory
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o Nesting sites, birds
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Population growth
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o dN = r • N ( K-N/K)
o dT |
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Density Independent Controls
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• Disease
• Natural Disaster |
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r selected species
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environmental instability reduces population before it approaches carrying capacity
- smaller short lived offspring - less or no care for offspring - Type III |
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K selected
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Population is near carrying capacity
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Biotic Potential
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o The maximum rate of increase under ideal condition
• rmax or intrinsic rate of increase |
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Exponential growth
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• dN/dt=rmax N
o dN/dT= Growth |
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Logistic Growth
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Growth that follows an S curve and levels off at the carrying capacity
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Carrying Capacity
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The max # that can be sustained in a given habitat
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Limiting factors
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lead a population towards carrying capacity
• An essential resource in short supply o availability of resources o predators o space- high density o competitors |
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Territory
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o Nesting sites, birds
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Population growth
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o dN = r • N ( K-N/K)
o dT |
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Density Independent Controls
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• Disease
• Natural Disaster |
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r selected species
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environmental instability reduces population before it approaches carrying capacity
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K selected
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Population is near carrying capacity
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Type I survivorship
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Long period of care as young
- fewer well provisioned young - death mostly comes much later in life |
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Type II survivorship curve
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birds, die at equal rate throughout lifespan
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Type III survivorship curve
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Many poorly provisioned offspring
- a lot die early in life |
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Competition
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-/- both will suffer a little
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Predation
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+/- beneficial to one but not the other
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Herbivory
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+/- beneficial to one but harmful to the other
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Parasitism
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+/- beneficial to one harmful to the other includes endo and ecto
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Disease
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+/- beneficial for bacteria or virus harmful for host
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Mutualism
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+/+ beneficial to both species
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Commenalism
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+/0 beneficial to one species the other is indifferent
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Amenalism
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-/0 negatively benefits one species and has no effect on the other
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Intraspecific Competition
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competition within a species, for dominance, mates, territory
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interspecific competition
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between two or more species
- if competing for the same limiting resource one will have to adapt or die |
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Ecological Niche
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All biological and abiological resources a species needs to survive
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Realized niche
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The niche a species is forced to occupy given the competitors
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Fundamental niche
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The niche a species would occupy without competition
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Resource Partitioning
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differentiation in ecology niches, enabling similar species to coexist
• They have to eat in different places and thus can live together |
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Character Displacement
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If two species are living together one could evolve to develop certain body morphology to deal with foods differently than the other species-
• two finches were occupying the same niche one evolves a bigger beak to eat bigger seeds and the smaller beak eats the smaller seeds so that they can both coexist • When allopatric speciation- they are apart from each other they have similar sized beaks more or less • when sympatric they have much more pronounced difference in beak size. |
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Allopatric speciation
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populations occupying the same niche independently of each other
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sympatric speciation
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species occupying the same niche in the same habitat will evolve at a much faster rate
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Becoming separate species
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For speciation to be complete there has to be some sort of reproductive barrier
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Predation
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if the prey population goes up so does the predator
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•Lotka-Volterre
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When the prey increases the predator does, predators get too many the prey decrease and therefore so does the predator etc.
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cryptic coloration
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camouflage, blend in to avoid predators
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aposematic coloration
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• rely on predators testing it out and realizing that they are poisonous
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Batesian mimicry
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a non-poisonous animal mimics a poisonous one
- monarch butterfly & other butterfly |
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Mullerian mimicry
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both species are poisonous but look the same thus enhancing the warning to predators
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defense chemicals
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• Nicotene is a defense for tobacco against herbivores
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producers
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first trophic level
- plants, autotrophs |
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primary consumers
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herbivores, second trophic level
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secondary consumers
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smaller carnivores, omnivores
- 3rd trophic level |
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energy transfer between trophic levels
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10% of the energy in the previous level is retained by the next level of consumer
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Area affect
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The larger the ______ the more species you will find
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Core Principles of Evolution
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o common decent with modification
o natural selection – Maintains favorable genotypes in a population and by doing so shapes evolution o All branches in the evolutionary tree of life come from the single common ancestor |
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Charles Lyell (1830)
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Earth is changing gradually, uniformintarianism- same processes that operate on the earth now have always
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JB de Lamarch (1809)-
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species change due to acquired characteristics
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George Cuvier
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species can become extinct
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Struggle for existence
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proposed by Darwin
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Survival of the fittest
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proposed by Herbert Spencer
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Artificial Selection
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humans chose organisms with specific characteristics as breeding stock, humans are performing the role of the environment
• Five vegetables derived from mustard • All dog breeds derive from one ancestral dog • One ancestral canine gave rise to all of the different canine species |
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Evidence for evolution
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• the fossil record presents a falsifiable claim
o Trilobites existed in ancient oceans from 500 mya-245 mya • primates arose 80 mya • Comparative Anatomy o homologous structures- arm structure very similar structure even though they have different uses, wings vs. arms, meaning they must somewhere had some common ancestor and later been modified to fit different uses |
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• Not a species
o populations evolve because one population in America could evolve but another of the same species might not need to in a different region of the world o two frog populations one light, the other dark used to be same species but evolved to have different genetic make-ups |
What is it that evolves?
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Hardy Weinberg equilibrium requirements
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• no migrations
• no mutations • no chance events • no natural selection • no non-random mating |
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Hardy Weinberg equation
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p2+2pq+q2 =1
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Mutations
Gene Flow Genetic Drift Non-random mating Natural Selection |
5 agents of microevolution
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Disruptive Selection
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changes in population genetics in which extreme values for a trait are favored over intermediate values
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Directional selection
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when natural selection favors a single phenotype and therefore allele frequency continuously shifts in one direction.
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stabilizing selection
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s a type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait value
A classic example of this is human birth weight. Babies of low weight lose heat more quickly and get ill from infectious disease more easily, whereas babies of large body weight are more difficult to deliver through the pelvis. |
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biological species concept
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Groups of individuals that potentially or actually can interbreed with each other
- Each creature that is able to interact and mate and create viable and fertile offspring |
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Morphological species concept
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• characterizes species in terms of structure, size, anatomy etc.
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paleontological species concept
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• fossil species with distinct morphological character
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ecological species concept
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focuses on species in terms of their ecological niches
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Phylogenetic species concept
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defines a species according to its genetic history
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Prezygotic mating barriers
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o impede mating between species or hinder fertilization of ova if members of different species attempt to mate
• habitat isolation • Temporal isolation- nocturnal vs. not • behavioral isolation- do the wrong dance you don’t have a chance • mechanical isolation- lock and key |
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Postzygotic barriers
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o Reduced hybrid viability- sickly
o reduced hybrid fertility- cannot mate and produce offspring o hybrid breakdown- can make a few generations but after a while there is breakdown because of the hybrid |
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allopatric speciation
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o physical barrier like mountains or something separate population A and B and limits gene flow until species A adapts to its side of the mountain and B adapts to the separate side and if these environmental difference are great enough you will end up with two different species
o extrinsic, geographic isolation not sufficient for speciation but there intrinsic differences are required i.e. behavior , genetic or morphological changes |
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sympatric speciation
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• worm holes in apples in forties was normal
• prefer to mate with flies that that eat the same type of apples as them, hawthorne vs. domestic showing the beginning of sympatric speciation |
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autopolyploid
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can arise from a spontaneous, naturally occurring genome doubling, like the potato.[citation needed] Others might form following fusion of 2n gametes (unreduced gametes). Bananas and apples
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o diverse diet, so when the environment they too can change no selection pr adaptation is required
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Why don't horseshoe crabs exhibit much speciation?
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o finches will only exist on a single seed from a single species and if that is not available they are forced to adapt or they don’t make it ]
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Why do finches exhibit high speciation?
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Adaptive Radiation
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many species arise from one ancestral species
o morphological changes o flowering plants |
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Thomas Malthus
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Essay On human population growth, arithmetically growing food resources cannot sustain exponential population growth
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Ozone
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O3 molecule, O2+ O was introduced when high energy lightning split the bond of O2
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first oxygen
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Photosynthesis in cynobacteria
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Bad ozone
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VOCs + NOx + Sunlight → O3 Combustion engines can create bad ozone that causes asthma
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Good Ozone
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O2 + high energy = O + O, O2 + O = O3
In the absence of this kind of layer, life could only evolve under water |
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Ice Albedo Effect
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the coefficient of reflectivity- some sunlight is reflected from ice, but some is absorbed, and melts ice, causing sea levels to rise
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Greenhouse Gasses
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With increasing CO2 levels in the atmosphere (290ppm → 580ppm) there is an increase in the greenhouse effect, warming the earth from 59 F to 61 F
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