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66 Cards in this Set
- Front
- Back
Fact |
Observation that has been repeatedly confirmed |
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Hypothesis |
tentative statement about a natural phenomenon that can be tested |
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Theory |
highly probable, well tested explanation of a natural phenomenon based on a large collection of observations and experiments |
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Proximate Causation |
HOW |
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Ultimate Causation |
WHY |
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Mutation |
a random change to a gene |
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Migration |
genes move from one population to another |
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Genetic Drift |
random sampling error over generations |
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Fitness |
the relative contribution of a genotype to the next generation; organisms with high genetic fitness are those favored by natural selection |
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Adaptation |
traits whose expression increases survival and reproduction |
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Speciation |
the evolutionary process or even by which a new species arises |
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Vicariance |
population geographically divided by a physical barrier |
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Dispersal |
individuals migrate from one area to another |
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Taxon |
any named group of organisms |
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Clade |
natural taxon based on common ancestry |
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Cladogram |
branching diagram of ancestor-descendant relationships |
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Sister Taxa |
descendants of a recent common ancestor |
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Synamorphy |
shared (2 or more taxa) derived character |
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Pseudopod |
temporary projections of eukaryotic cell membranes or unicellular protists |
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Cilium |
a hairlike, vibratile organelle found on many animal cells; could be used for moving particles along the cell surface or for locomotion |
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Flagellum |
whiplike organelle of locomotion |
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Collagen |
fibrous connective tissue composed of protein |
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Spicule |
skeletal elements |
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Spongin |
fibrous, collagenous material forming the skeletal network of some sponges |
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Ostium |
incurrent opening to a canal |
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Osculum |
excurrent opening to a canal |
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Choanocyte |
"collar cells" that circulate water and trap food (have microvilli collars and flagella); resemble choanoflagellates |
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Erasmus Darwin |
hypothesized common ancestry of organisms |
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Charles Lyell |
established uniforitariansim |
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Jean Baptist Lamarck |
discovered the inheritance of acquired characteristics; transmutation (physical changing) of species |
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Charles Darwin |
developed theory of natural selection - heritable traits beneficial to the survival are selected and become common in a population |
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Gregor Mendel |
studied inheritance of traits in peas - genetics; identified dominant versus recessive traits |
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Carolus Linnaeus |
developed rules for naming species |
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Willi Hennig |
popularized the idea of phylogenic systematics |
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Lynn Margulis |
proposed the theory of endosymbiosis |
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Modern Science |
seeks to explain natural phenomena in natural terms |
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What are the three attributes of science? |
Testable Repeatable Falsifiable |
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Binomial Nomenclatue |
two names for every species (Genus and species epithet) |
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Hypothetico-Deductive approach |
Observation, Question, Hypothesis, Empirical Test, Conclusion |
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Is evolution a fact or a theory? |
both |
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Natural Selection |
heritable traits beneficial to survival are selected and become common in a population |
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Taxonomy |
the ordering and naming of organisms |
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Phenetics/Evolutionary Taxonomy |
taxa are defined by physical characteristics |
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Phylogenetic Systematics |
taxa are defined by common ancestry |
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Monophyletic group |
group consisting of an ancestor and ALL of its descendants |
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Paraphyletic group |
group consisting of an ancestor and some, but not all, of its descendants |
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What is the geologic age of the oldest prokaryote fossil? What modern organisms do they resemble? |
First prokaryotes appeared ~3.5 billion years ago
Earliest forms resemble cyanobacteria |
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What are the three clades of life? What clade do we belong to? |
Archaea Eukarya Bacteria
We belong to the Eukarya |
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Prokaryotic Cells |
(Archaea, Bacteria) No true Nucleus Lack organelle single-celled organisms |
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Eukaryotic Cells |
well-defined, membrane-bound nucleus organelles present can be unicellular, colonial, or multicellular |
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How do plants, fungi and animals obtain energy? |
Plants are photosynthetic Fungi absorb their nutrition Animals ingest their nutrition |
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What organism is the sister taxon to animals? |
Choanoflagellatea |
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Theory of Endosymbiosis |
origin of eukaryotes in which one prokaryote came to live inside another prokaryote and symbionts eventually became organelles
(support: mitochondria and chloroplasts have a double membrane and they have their own DNA but no nucleus) |
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What is similar and different when comparing sponges to all other animals? |
Sponges and other animals are unicellular, however they lack true tissue |
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How do sponges reproduce? |
Sponges can reproduce sexually (organism has both male and female parts) or asexually by budding |
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Four Clades of Porifera and their spicules |
Calcarea: calcium carbonate spicules Hexactinellida: silica spicules Demospongiae: spicules can be silica, spongin or both (majority of sponge species) Homoscleromorpha: "incipient epithelium" but not true tissue |
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Allopatric Speciation |
occurs in small populations that become physically isolated, leading to reproductive isolation |
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Dispersal |
individuals migrate from one area to another |
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Vicariance |
population is geographically divided by a physical barrier |
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Sympatric Speciation |
continuous population (no geographic isolation), but gene flow is so low that segments of the population become reproductively isolated |
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What must be present in a population before evolution can occur? (What is the prerequisite or "raw material" of evolution?) |
genetic variation |
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Charles Darwin's Four Postulates |
-individuals within populations are variable -variations among individuals are heritable -in every generation. some individuals are more successful at surviving and reproducing than others -survival and reproduction are nonrandom |
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Phenotype |
an observable trait of an organism |
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Genotype |
the genetic code for phenotype |
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Does natural selection act on individuals or populations? |
Natural Selection act on individuals; populations evolve |
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Does natural selection act on phenotypes or genotypes? |
Natural Selection acts on phenotypes; but evolution consists of changes in gene frequency |