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37 Cards in this Set
- Front
- Back
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What evidence is there for evolution?
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Fossils -verify changes over mill. of yrs.
Shared Features -Including genetic & biochemical processes eg. glycolysis Patterns of geographic variation -morphological, ecological, phenological, genetic patterns of variation are coincident w/geographically varying physical features |
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What are two levels of evolution?
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Anagenesis -Changes within a species
Cladogenesis -Splitting of one species into two |
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What is evolution?
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Genetic Changes through time
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Evolutionary Adaptation?
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The close correspondence b/t organisms & their environment
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2 types of evolution?
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Anagenesis -changes w/in a species
Cladogenesis -splitting of one species into two |
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What is a cline?
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When variation among population is continuous (gradual) across range of distribution of a species
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What are two types of speciation?
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Allopatric specieation -geographic isolation prevents gene flow, allows divergence of populations
Sympatric speciation -occurs w/out geographic separation; strong barrier to gene flow necessary |
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What are 3 sources of genetic variation?
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Mutations -alterations of DNA; changes in single bases; insertions; deletions
Genetic recombinations Gene flow |
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What are 3 types of isolation?
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Temporal Isolation
Habitat Isolation Floral Isolation |
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What is Temporal isolation?
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Seasonal -species flower at different times of the year
Diurnal -species flower at different times of the day |
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What is habitat isolation?
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Species that occupy different habitats may be reproductively isolated
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What are floral isolations?
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-Adaptations to attract different pollinators limit or prevent gene exchange b/t species
-Pollinia that differ in shape, and are not likely to fit into stigmatic slit of another species |
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What is Chasmogamous?
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Flowers that open
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What is Agamospermy?
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Production of embryos without fertilization
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What are types of reproductive modes?
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Self-fertilization
Chasmogamous Agamospermy |
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What is Hybrid inviability?
Hybrid floral isolation? Hybrid sterility? Hybrid breakdown |
-may not reach reproductive maturity
-may not be pollinated -may be vigorous but sterile b/c meiosis does not proceed properly |
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What does the capacity of animals to interbreed distinguish?
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Distinguishes species
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What is hybridization?
How many estimated natural interspecific plant hybrids? |
Mating b/t species
70,000 |
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What is the BSC?
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Biological species concept -a species is a group of interfertile individuals; useful in biology
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What are problems with BSC in plants?
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Interfertility varies greatly among plants
Selfing individuals would be separate species, as would asexual clones Morphologically distinct groups that hybridize would have to be recognized as one species Even with hybridization, distinct lineages persist |
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What are Viridophytes?
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Green Plants
Includes "green algae" and land plants Monophyly supported by DNA, and structural and chemical features |
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What are Embryophytes?
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Land plants
Resting embryo state Support monophyly |
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What are Bryophytes?
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Include liverworts, hornworts, mosses -non-vascular plants
Gametophyte generation is dominant |
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What are Tracheophytes?
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Vascular plants
Dominant sporophyte generation xylem with tracheids |
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What are the three clades of Tracheophytes?
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1. Lycophytes -(club mosses, spikemosses, quillworts) have microphylls
2. Monilophytes -("seed free plants") 3. Spermatophytes -("seed plants" -gymnosperms and angiosperms) have megaphylls |
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What are Spermatophytes?
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Seed plants
270,000 species Gymnosperms (cycads, ginko, conifers) and the Angiosperms (flowering plants) |
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What are Angiosperms?
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-Monophyletic
-Reduced female gametophyte -Double fertilization -Carpel w/ receptive stigmatic surface -Arose 135 mill. yrs. ago |
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What are lycophytes and monilophytes considered?
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"Fern allies" and Ferns
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What are Lycophytes?
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-Spirally arranged microphylls
-Sprangia borne in strobili -Selaginellaceae (spike mosses) -Isoetaceae (aquatic or semi-aquatic) |
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What is the family Equisetaceae?
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Horsetails
-Jointed, ribbed stems -Microphylls small and scale-like, whorled -Sporangia in terminal strobili |
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What are Sporangia grouped into?
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Sorus
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Marsileaceae?
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Water clover found in bison wallows
Sori enclosed in bean-or pea-shaped sporocarps at a base of petiole |
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Gymnosperms?
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-Molecular evidence indicates a monophyletic group, but their exact relationship isn't known
-Seeds not enclosed in carpels -Four major extant lineages -All are woody |
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Coniferales?
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Conifers
-Bear seeds in cones -largest and most ecologically important group of "gymnosperms" |
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Pinaceae?
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Pine Family
-linear or needlelike leaves (fir, spruce, larch) -Monoecious (ovulate and staminate cones borne on same plant) -Key characters: needle length, sheath length |
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Cupressaceae
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Cypress or Redwood family
-trees or shrubs -Monoecious or dioecious -highly valuable wood -Tallest and most massive plants on earth |
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What are core tricolpates?
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Monophyly supported by DNA
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