Final exam Flashcards
evolution
decent with modification/change in genetic composition in a population from generation to generation
aristotle
life forms could be arranged on a ladder or scale of increasing complexity (scale of nature)
lamarcks 2 principles
use and disuse and inheritance of acquired characteristics
use and disuse
parts of the body that are used extensively become larger and stronger, and those that don’t deteriorate
inheritance of acquired characteristics
organism could pass these modifications to their offspring
natural selection
individuals that have certain inherited traits tend to survive and reproduce at higher rates then others because of these traits
First premise of evolution by natural selection
Each species produces more offspring then will survive to maturity
Second premise of evolution by natural selection
Individuals in a population exhibit inheritable variation in their traits
Third premise of evolution by natural selection
Organisms compete with one another for the resources needed to survive
Fourth premise of evolution by natural selection
Individuals with most favorable traits are most likely to survive and reproduce
Fossil record
How past fossils differ to present fossils and that many species become extinct in all so show how various changes occurred in various groups of organisms also shed light on origins of new groups of organisms
Direct observations
Directly observing natural selection leading to adaptive evolution
Homology
Similarity resulting from common ancestry used to make testable prediction and explain observations that would otherwise be confusing
Biogeography
Study of the geographic distribution’s of species predict where fossils and different groups of organisms may be found
Homologous structures
Structures in different species that are similar because of common ancestry
Analogus structures
Having characteristics that are similar because of convergent evolution
Convergent evolution
Evolution of similar features in independent evolutionary lineages
Harry-Weinberg theorem
State of a population in which frequencies of alleles and genotypes remain constant from generation to generation
Hardy Weinberg equation
P plus Q equals one
Usefulness of Hardy Weinberg model two population geneticist
Calculates allelic frequencies for particular gene to see if a population is evolving with respect to that particular trait
Conditions a population must meet in order to maintain Hardy Weinberg equilibrium
No mutations random mating no natural selection extremely large population size no gene flow
Micro evolution
Evolutionary change within a species or small group of organisms especially over a short period
Genetic drift
Chance events caused unpredictable fluctuations in allele frequency’s from one generation to the next
Gene flow
Transfer of alleles from one population to another
Mutation
Change in nucleotide sequence of an organisms DNA
Bottleneck effect
Genetic drift that occurs when the size of a population is reduce typically the surviving population is no longer genetically representative of original population
Founder effect
Genetic drift that occurs when few individuals become isolated from a form of new population who is gene pool composition is not reflective of that of the original population
Factors that can produce geographical variation among closely related populations
Interacting species drift microenvironments
Cause of nearly all genetic variation in a population
Mutation random mating random fertilization recombination between Homo Logus chromosomes during meiosis
Macro evolution
Evolutionary change above the species level
Driving forces of macro evolution
Origin of a new group of species of speciation events and the impact of mass extinctions on the diversity of life and it’s subsequent recovery
Driving forces of microevolution
Mutation selection Gene flow and genetic drift
Genetic variation
Differences among individuals in the composition of their genes or other DNA segments
Sources of genetic variation
Mutation gene flow sex gene transfer
Five factors that affect Hardy Weinberg equilibrium
Mutations recombinations during sexual reproduction genetic drift gene flow natural selection
Directional selection
Shifts the overall make up of a population by favoring the variance that are at one extreme of the distribution
Disruptive selection
Favors variants at both ends of the distribution
Stabilizing selection
Removes extreme variance from the population and preserves intermediate types
Sickle cell
Strikes people with two copies of sickle cell allele
Heterozygote advantage
Occurs when heterozygotes have a higher fitness than do both homozygotes
Sickle cell and micro evolution
In regions were the malaria parasite is common selection favors individuals heterozygotes for the sickle cell allele
Industrial melanism
Natural selection pressures due to man-made influences have led to color changes in different species
Controversy surrounding Darwin’s classic example of finches as an example of evolution by natural selection
Various species are known to be interbred
Species appear to integrate and are often indistinguishable
Fluctuation about a mean
Evidence of macro evolution
Speciation
Speciation
Origin of new species
Biological species concept
Species is a group of populations whose members have the potential to interbreed in and produce offspring
Morphological species concept
Defines a species by structural features
Ecological species concept
A species in terms of ecological niche
Phylogenetic species concept
Defines a species as the smallest group of individuals on a phylogenetic tree
Molecular clock
Average rate at which species genome accumulates human mutations used to measure their evolutionary divergence end in other calculations
Punctuated equilbria
Fossil record long periods of a parent stasis in which a species undergoes little or no morphological change interrupted by relatively brief periods of sudden change
Gradualism
Gradual reform
Reproductive isolation
Existence of biological factors that impede members of two species from producing
Habitat isolation
Two species that occupy different habitats within the same area encounter each other
Temporel isolation
Species breed during different times
Behavioral isolation
Courtship rituals that attract mates and behaviors unique to a species reproduction
Mechanical isolation
Mating is attempted but morphological differences prevent successful reproduction
Gametic isolation
Sperm of one species may not be able to fertilize the eggs of another species
Reduced hybrid viability
Jeans of different parent species may interact in ways that impair the hybrids development or survival in the environment
Reduced hybrid fertility
Hybrids are sterile
Hybrid breakdown
Second generation is sterile
Allopatric speciation
Gene flow is interrupted or reduced when a population is divided into geographically isolated subpopulation
Sympathetic speciation
Speciation takes place in a geographically overlapping populations
Polyploidy
Presence of excess of chromosomes due to accidents during cell division
Autopolyploid
Individual with more than two chromosome sets
Allopolyploid
Species with multiple sets of chromosomes derived from different species
Adaptive radiation
Diversification of a group of organisms into forms filling different ecological niches
Population
Group of individuals of the same species that live in the same area and interest we produce fertile offspring
Community
All the organisms that inhabit a particular area and assemblage of populations of different species of living close enough together for potential interaction
Ecosystem
All the organisms in a given area as well as the abiotic factors with which they interact ;one or more communities
Abiotic factors
Included nonliving attributes such as temperature light water and nutrients
Biotic factors
Including other organisms that are part of and individuals environment
Tropical forest
Occurs in equatorial sub equatorial regions
Deserts
Occur near 30° north and south latitudes
Savanna
Occurs in equatorial and sub equatorial regions dry and warm
Chaparral
Mid latitude coastal regions cool shrubs and small trees
Temperate grassland
Planes and prairies
Northern coniferous forest
Largest terrestrial biomes Pinetrees
Temperate Broadleaf forest
Found in mid latitude’s colorful trees
Tundra
Polls Moss grass wolves and bears
Density
Number of individuals per unit area or Volume
Distribution
Geographical area within which of that species can be found
Parasitism
Symbolic relationship in which one organism that a parasite benefits at the expense of another the host
Mutualism
Both participants benefit
Commensalism
One organism benefits but the other is neither helped or harmed
Amensalism
Both organisms benefit
Predators in community structure
Keep pray at a healthy number to protect plants
Coevolution
Joint evolution of two interacting species each is response to selection imposed by the other example would be be in flower
Ecological succession
Transition in the species composition of a community following a disturbance establishment of a community in an area virtually Baron of life
Primary succession
Type of equal logical succession that occurs in an area where there originally no organisms present and we’re so I’ll has not yet found
Secondary succession
Occurs where an existing community has been cleared by some disturbance that leaves the soil or substrate intact
Patterns of desperation
Clumped uniform and random
Gross primary production
Total primary production of an ecosystem
Net primary production
Gross primary production of an ecosystem minus the energy used by the producers for respiration
Trophic levels
Primary producers primary consumers secondary consumers Teritary consumers quaternary consumers
Primary producer
Plant
Primary consumer
Herbivore
Secondary consumer
Carnivore
Factors that limit productivity
Nutrients water and light
Productivity to clients at each trophic level
Energy loss during respiration can’t be produced by another level 80 per percent or 95% of energy is not passed on
Energy pyramids
Show level of energy produced in that biomass
Biomass Pyramid
Show how energy levels transfer and sharply decrease between traffic levels
Detritivores
Consumes decomposing plants animals and feces
Survivorship a graph type one
High probability of living through early and middle life
Survivorship graph type two
Constant death rate
Survivorship graph type III
Hi young death rate low death rate for survivors
R selection
High growth rate less crowded ecological niche and produce many offspring
K selection
Favor individuals who compete for resources produce few slowly developing young stable population of long-lived individuals
Density dependent growth regulating affects
Referring to any characteristic that varies with population density
Density independent
Referring to any characteristic that is not affected by population density
Interspecific competition
Competition for resources between individuals of two or more species when resources are in short supply
Competitive exclusion
One population will use the resources more efficiently and have a reproductive advantage of that will lead to elimination of another population
Symbiosis
Ecological relationship between organisms of two different species that live together in direct and intimate contact
Effects of deforestation
Loss of habitat less quantity for water in atmosphere can’t hold as much water
