Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
EBIO Exam 1
Vocabulary words from lectures 1-9
| Question | Answer |
|---|---|
| Biological evolution | change in the genetic properties of groups of organisms (“populations”) over the course of generations Often referred to more simply as ‘descent with modification’ or ‘genetic change over time’ |
| Natural selection | ONE mechanism which evolution occurs, but natural selection and evolution are NOT one and the same thing. |
| Five misconceptions of biological evolution: | 1: Evolution and natural selection are the same thing 2: Individual organisms undergo biological evolution 3: Evidence for evolution is only a theory 4: Evolution cannot explain the origin of new species 5: Evolution has been proved |
| essential ism | Concept of eidos ‘form’ or ‘idea’ or ‘essence’ e.g. horses have an immutable (unchangeable) essence, but each individual has its imperfections This was the belief before Darwin |
| Two of Darwins theories from the "origin of Species" | 1.Descent with modification (evolution) 2.Causal agent of evolutionary change (natural selection) |
| Evolutionary theories after Darwin | mutationist theories -argued that discretely different organisms arose via mutation and that natural selection was not required for the origin of new species. Mutation seen as an alternative to natural selection |
| Biological species concept (BSC): | by Mayr: species are groups which are reproductively isolated (do not exchange genes) from other groups |
| Theory of geographic (allopatric) speciation: | Mayr: new species form when populations become geographically isolated, and thus can undergo genetic divergence |
| Theory of founder effect speciation: | Mayr:drastic reductions in population size promote speciation (e.g. via ‘reorganizing’ the genome) |
| genotype | the set of genes in an individual’s DNA |
| genetic drift | Genes mutate at a low rate, typically too low a rate to cause a population to shift from one genotype to another; thus shifts occur instead by random fluctuations |
| reproductive isolation | Species are characterized by barriers to genetic exchange and interbreeding |
| phylogeny | tree of life |
| Fundamental principles of evolution | 1. pheno vs. geno & pheno + geno 2. heredity based on... 3. evolution is populational 4. random and nonrandom changes 5. slight selection can = 6. mutations can accumulate 7. dif. among species are adaptive 8. geographic isolation does what? 9. si |
| tree topology | tree branching order, pattern + branch lengths of tree |
| homologous traits | reflect shared ancestry |
| Homology | possession by two or more groups (e.g. species) of a character state derived from their common ancestor (‘unique origin’) |
| Maximum parsimony | Minimize change-fewest changes = most simularities |
| Homoplasy | possession by two or more groups (e.g. species) of a similar or identical character state that has not (not! not! not!) been derived by all the members of the group from their common ancestor (‘independent origin’) |
| monophyletic group | grouping that includes all descendents of the most recent common ancestor |
| polyphyletic group | in which members are derived from different ancestors. |
| paraphyletic group | one that includes some, but not all, descendents from their most recent common ancestor. |
| sister group | 2 clades or lineages sharing a most recent common ancestor. |
| Character mapping | reconstruction of the history of evolutionary change in interesting characters by inferring character states of ancestors on a phylogeny . |
| characters | a feature or trait (e.g. color of snail shell) |
| 4 common patterns of evolutionary change | 1) Most features modified from pre-existing features 2) Homoplasy is common, change in form associated with change in function 3) Rates of character evolution differ 4) Evolution is often gradual |
| Conservative characters | physical traits that are retained with little or no change over long periods of time |
| mosaic evolution | principle says that a species evolves not as a whole, but piecemeal, with different characters evolving quasi-independently. |
| adaptive radiation | the evolution of ecological and phenotypic diversity within a rapidly evolving lineage. Trees don't look like they go in order |
| character states | one of the variant conditions of a character (e.g. brown or yellow shell color, A or T at a nucleotide position) |
| ancestral state | state found in common ancestor. |
| derived state | state that has evolved from the ancestral state. |
| synapomorphy | a shared derived character state |
| The ‘molecular clock’ | the concept of a steady rate of change of DNA sequences over time, providing a basis for dating the time of divergence of lineages ‘DNA differences build up steadily through time’. |
| Gene flow | the incorporation of genes into the gene pool of one population from one or more other populations |
| hybridization | – interbreeding between species (‘gene flow’ between species) |
| stasis | period of little or no evolutionary change |
| Phyletic gradualism | a traditional model where evolutionary change is gradual and not necessarily associated with speciation |
| speciation | when a new form of species occurs-can be for many reasons |
| punctuated equilibrium | a new species diverges rapidly, but then continues without further change-phenotypic evolution occurs at speciation events only |
| punctuated gradualism | linage evolves in rapid spurts from one equilibrium to another, but speciation does not necessarily occur |
| Hypothesis of ‘ecological opportunity’ | adaptive radiation in phenotypic and species diversity occurs when empty or underutilized ecological niches (habitats) are filled (and it thus follows that diversification requires empty or underutilized niches) |
| nine general patterns 1 | 1) Climates and the distribution of oceans and land masses have changed over time, affecting the geographic distributions of organisms |
| nine general patterns: 2 | 2) The taxonomic composition of the biota has changed continually as new forms originated and others became extinct |
| nine general patterns: 3 | 3At several times, extinction rates have been particularly high (so called mass extinctions) |
| nine general patterns: 4 | 4Especially after mass extinctions, the diversification of higher taxa has sometimes been relatively rapid |
| nine general patterns: 5 | 5The diversification of higher taxa has included increases both in the number of species and in the variety of their form and ecological habitats |
| nine general patterns: 6 | 6) Extinct taxa have sometimes been replaced by unrelated but ecologically similar taxa |
| nine general patterns: 7 | 7Of the variety of forms in a higher taxon that were present in the remote past, usually only a few have persisted in the long term |
| nine general patterns: 8 | 8The geographic distributions of many taxa have changed greatly (continents moved, organisms moved) |
| nine general patterns: 9 | 9Over time, the composition of the biota increasingly resembles that of the present |
| Precambrian times | 1-origin of Eukaryotes 2-photosynthesis evolved 3-evolution of multicellularity division of labor & jack of all trades is a master of none-EVOLVED INDEPENDENTLY 4-organisms were anaerobic |
| Emergence of life | short RNA-like molecules were early replicators |
| Paleozoic life cambrian explosion | most phyla originated, lots of diversification over short amount of time, Cambrian explosion ended with mass extinction |
| Paleozoic life ordovician to devonian | first terrestrial life, plant spores populate land first-greatly diversified, the earliest known arthopods, then vertebrates, ordovician to devonian |
| Paleozoic life end- permian mass extinction | 96% of all species became extinct, few thousand years, end- permian mass extinction |
| mesozoic life | first dinosaurs first mammals first flowering plants period of triassic, jurassic, and cretaceous great diversification of dinosaurs |
| Cenozoic life | the age of mammals-but with extinction of dinosaurs no real explosion of diversification of mammals, Tertiary (T) |
| Late Cenozoic | Pleistocene speciation and 'recent' ice ages, short time period, could migrate between land masses, climate changed there was a move south, glacial refugia |
| glacial refugia | separated areas where favorable conditions persisted during glacial periods |
| biogeography | the study of the geographic distributions of organisms |
| historical biogeography | using both historical and geological circumstances |
| ecological biogeography | ecological factors operating in present time |
| Wallace’s line | separates islands that exhibit very different fauna, despite their close proximity and climatic similarity – the islands only approached each other recently, and belong to two different realms: Oriental and Australian |
| Endemism | restriction, to one biogeographic realm is common |
| disjunct distributions | their distributions have conspicuous gaps, sometimes between realms |
| extinction | loss of species/populations can leave gaps in the distribution |
| dispersal | movement of individuals, can result in range expansion |
| vicariance | separation of populations of a widespread species by barriers arising from changes in geology, climate or habitat |
| Phylogeography | the description and analysis of the processes that govern the geographic distribution of lineages of genes, especially within species and among very closely-related species Relies on phylogenetic analysis, usually of multiple genes. |
| dispersal ability | cannot or have not gotten to certain areas |
| realized niche | exclusion from certain areas, for example due to competition, predation, or lack of adaptation (e.g. due to gene flow – which limits adaptation and reduces population persistence) =species range |
| fundamental ecological niche | set of environmental conditions in which a species can maintain a stable population size (i.e. the physiological tolerance of the species to environmental conditions) |
| Realized ecological niche | actual niche space occupied by a species = species range The realized niche is smaller than the fundamental niche because species are excluded from certain areas by lack of adaptation, competitors, predators |
Created by:
smb10689
Popular Biology sets