vocabulary Flashcards
scala naturae
the belief in ancient times that all life was ordered in a hierarchical with humans at the top due to their intelligence
Aristotle, largely discredited today
fossil
geological remains of a once living organism
catatrophism
geology theory that the earth was shaped by sudden, unpredictable events that were major but short lived
uniformitarianism
geology theory that the earth was shaped by gradual changes over time due to natural processes
inheritance of acquired traits
if an organism changes to adapt to environment and lives, than those traits are passed down to next generation
extant
modern-day, currently living organisms
endemic
species unique to a defined geographic location
over-population
struggle for existence
heritable
characteristic passed down from parent to offspring
Homologous structure
functionally different features with similar construction due to common ancestry
vestigal structure
structures that have no apparent function, residual parts from a past ancestor
molecular homology
similar molecular composition
evidence of common ancestor
analogus structure
structure that perform the same or similar function but did not evolve from common ancestor feature
convergent evolution
biogeography
a study of the distribution of species over space and time
neutral variation
traits that do not benefit the organism’s survival, but are kept and passed down
adaptation
traits modified over time so that individuals with the trait are more likely to survive and reproduce
Heritable trait
traits with a genetic basis
Allele
different version of a gene in a population
Phenotype
physical expression of a gene
Genotype
the actual genes
Microevolution
generation to generation change in allele frequency in a population
Fixed allele
an allele that exists as the only variant for that gene in that population
Polymorphism
2+ more versions of a trait present for a species
Mutation
mistakes in DNA replication that occur during meiosis
Genetic drift
effects of random chance on a population, change in gene frequency
Founder effect
a few individuals start a new population
Bottleneck effect
a sharp reduction in population size due to a natural disaster
reduces gene frequency
Directional selection
a mode of negative natural selection in which an extreme phenotype is favored over other phenotypes
Diversifying selection
describes changes in population genetics in which extreme values for a trait are favored over intermediate values
Stabilizing selection
a type of natural selection in which the population mean stabilizes on a particular non-extreme trait value
Sexual selection
a mode of natural selection in which members of one biological sex choose mates of the other sex to mate with, and compete with members of the same sex for access to members of the opposite sex
Intra-sexual selection
the act of competing with members of one’s own sex
Inter-sexual selection
involves one sex having preferences for members of the opposite sex who possess certain qualities
Biological Species Concept
group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring members of other populations (defines a species)
Morphological Species Concept
defines species as groups of individuals that are morphologically similar to one another and are morphologically distinct from other such groups (physical traits)
Argument from authority
a form of argument in which the opinion of an authority on a topic is used as evidence to support an argument
Hybridization
crossing of species
Asexual reproduction
type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes
Self fertilization
the fertilization of plants and some invertebrate animals by their own pollen or sperm rather than that of another individual
Fossil species
an extant taxon that cosmetically resembles related species known only from the fossil record
Ring species
gene flow occurs between neighboring populations, but at the ends of the ‘ring’, populations don’t interbreed
Allopatric speciation
populations become geographically isolated from each other to an extent that prevents or interferes with gene flow
Sympatric speciation
evolution of a new species from a surviving ancestral species while both continue to inhabit the same geographic region
Polyploidy
heritable condition of possessing more than two complete sets of chromosomes
Hybrid zone
locations where hybrids between species, subspecies, or races are found
Pre-zygotic reproductive barrier
keep organisms of different species from mating with each other and forming hybrid species
Post-zygotic reproductive barrier
the hybrids cannot reproduce, are sterile, have abnormalities
Gradualism
Punctuated equilibrium
evolution that is characterized by long periods of stability in the characteristics of an organism and short periods of rapid change during which new forms appear
Adaptive radiation
an evolutionary process that produces new species from a single, rapidly diversifying lineage
Mass extinction
extinction of a large number of species within a relatively short period of geological time
Oxygen revolution
an event stretching over the Proterozoic eon when molecular oxygen levels in the atmosphere rose and carbon dioxide levels decreased
Endosymbiosis
a form of symbiosis wherein the symbiont lives within the body of its host
ecology
study of the relationships among living organisms, including humans, and their physical environment.
population ecology
a sub-field of ecology that deals with the dynamics of species populations
population
A group of individuals of the same species within a community
density
concentration of individuals within a species in a specific geographic locale
dispersion- clumped/uniform/random
the spreading of a population or organism away from its parents
clumped:individuals are clustered in groups
uniform: individuals of a population are spaced more or less evenly
random: individuals are distributed randomly, without a predictable pattern
sex ratio
the ratio of males to females in a population
age structure
The composition of a population in terms of the proportions of individuals of different ages; represented as a bar graph
age structure diagram (and types of age structure diagrams)
expansive: large percentage of the population is younger group, these populations have higher fertility rates
constrictive: lower percentage of younger people
stationary: somewhat equal numbers for all age groups
birth, death rates
number of babies born per population
divide babies by pop and * 1000
same with death rate but with dying individuals
fertility rates
the ratio between the number of live births in a year and the whole female population of childbearing age
rate of increase
(birth rate - death rate) / initial population
life history
organism’s pattern of survival and reproduction, along with the traits that directly affect survival and the timing or amount of reproduction
generation time
the average interval between the birth of an individual and the birth of its offspring
survivorship
proportion of a population that survives from one age to the next
survivorship curves (and types of survivorship curves)
survivorship curve is a graph showing the number or proportion of individuals surviving to each age for a given species or group
Type I: High survival until old age
- typical in species with few offspring and high parental care
Type II: constant mortality/survival probability regardless of age
Type III: Low survival at young age
- typically in species with many offspring and low parental care
r and K strategies
Density dependence
Density independence
Ecological footprint
Community
Assemblage
Species richness
Relative abundance
Dominant species
Biomass
Foundation species
Ecosystem engineer
Keystone species
Predation
Batesian mimicry
Müllerian mimicry
Aposomatic coloration
Selfish herd
Eyespot mimicry
Co-evolution
Symbiosis
Mutualism
Endosymbiosis
Parasitism
Parasite
Pathogen
Commensalism
Competition
Competitive Exclusion Principle
Niche
Fundamental vs realized niche
Character displacement
Resource partitioning
Competition
Competitive Exclusion Principle
Niche
Fundamental vs realized niche
Character displacement
Resource partitioning
Trophic structure
Food chain
Food web
Primary producer
Primary consumer
Secondary consumer
Tertiary consumer
Omnivory
Detritivory
Diet shifts
Trophic cascade
Top down control
Bottom up control
