evoloution vocabulary Flashcards
variation
the differences between individuals, number of possible alleles offspring can inherit
Biological evolution
An inherited change that happens within a POPULATION, not individual
Adaptation
a structure, behaviour, physiological process that helps an organism survive and reproduce
Fitness
another word to describe reproductive success, relative contribution (#) an organism makes to the next generation by producing viable offsprings
Viable
can survive long enough to reproduce
Structural adaptation
Specific part of feature of the organism’s body, eg fluffy feathers
Physiological adaptation
Permits an organism to perform a specific function, eg hibernation
Behavioural adaptation
ways an organism acts, eg hunting strats, migration
Microevolution
Change in allele frequencies with a population over successive generations
Allele frequency
Number of copies of an allele compared to the total number of alleles in a population
Macroevoloution
Progression of biodiversity over a long period of time, descent of many species from a common ancestor
Involved speciation
Fossils
Chronological collection of lifes remains in sedimentary layers, hard tar pits, volcanic ash etc. Shows history of life by showing kinds of species that were alive
transitional species
A species that has characteristics that are shared by more than one major group of organisms, show intermediary links btw groups of organisms
Comparative anatomy
study of similarities and differences in anatomy between species
Homologous
Anatomical structures found in different species, have similar structure and derived from a common ancestor. Can have a different function
Analogous
Structures have similar functions but DO NOT share common ancestor
Vestigal
Homologous characteristics of organisms that have lost all or most of their original function in a species through evolution eg human tail bone
Biochemical analysis (DNA)
Scientists can determine how closely related 2 organisms are by comparing DNA and proteins, use DNA barcoding
Embryology
Study of early pre-birth stages of an organisms development
Biogeography
Study of the distribution of organisms and ecosystems in space and through geological time
Mechanisms for evolution
Mutation, natural selection, non-random mating, genetic drift, gene flow
Mutations
change that randomly occurs in the DNA of an individual that is HERITABLE, only source of new alleles/genes
neutral mutations
occur in non-coding regions of genetic material and do not benefit or harm the organism, eg attached earlobes
Natural selection
organisms with advantageous heritable traits are selected for, survive and reproduce passing their traits to offspring
Directional, Disruptive and stabilizing natural selection
Directional: Results in shift in one extreme aspect of a trait, moves curve one direction. Eg selects for one extreme
Disruptive: natural selection selects for both extremes and removes the most common characteristics. Extremes may become separate species
Stabilizing: Favours intermediate, selects against extreme
Inbreeding
closely related individuals breed together
Preferred phenotypes
selecting a mate based on physical and behavioural traits
Disassortative mating
Organisms with different phenotypes mate tg
Genetic drift
Changes in gene/allele frequencies in small populations, alleles lost at random or by chance
Bottleneck affect
Large, temporary reduction in population resulting in genetic drift. occurs by change, eg environmental disaster
Some alleles may be lost as only few survive and produce from natural disaster
Founder effect
by chance, small # OF INDIVIDUALS establish a new population distant from original
Causes limited number of alleles to be present, loosing genetic diversity
Geneflow
Movement of alleles from one population to another by movement of individuals, must have migration of fertile individual, changes allele frequency
Species
carl linneus says its a group defined by morphological differences from all other life forms, today it focuses on genetics and biochem
Biological species concept
population where individuals reproduce naturally, and produce a viable offspring
Speciation
Formation of a new species, allopatric and sympatric
Allopatric speciation
new species form when a single species is separated into 2 isolated populations by a geographical barrier,
physical separation prevents exchange of genetic info
Sympatric speciation
Individuals within a population become genetically isolated from larger pop without geographic isolation
Reproductive isolating mechanism
any behavioural, structural or biochemical trait that prevents individs of a diff species from reproducing successfully
Prezygotic
prevents mating or fetilization
Postzygotic
prevent viable and fertile offsprings
Ecological isolation (MP)
Species that occupy separate habitats or seperate niches of the same habitat do not meet to mate
Temporal isolation (MP)
temporal conditions refer to time of day, seasons or diff years, diff species mate at diff times
Behavioural isolation (MP)
The courtship and mating cues for attracting a mate are very specific for each species, rituals aren’t recognized by one another
Mechanical isolation (FP)
Structural differences in reproductive organs prevent copulation eg divided into sep species bc of gentalia shape
Gametic isolation
Prevents fertilization at the molecular level, egg n sperm fail to fuse, does not recognize male sperm (attacker)
Zygotic mortality
fertilized zygote die before birth, chromosomes arent compatible
Hybrid inviability
Embryo develops and dies before birth or is born alive but hybrid is weak and does not survive to reproduce
Hybrid infertility
Hybrids do dev normally to reach sexual maturity but are sterile (do not prod viable gametes)
assortive mating
when indivis mate w partners that are like themselves in certain characteristics
Sexual selection
certain characteristics are actively sought out by one sex usually females, one result is sexuak dismorphism (marked diff btw males and females)
