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AP Biology Chapter 20 Flashcards

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4987705921Phylogeny- The evolutionary history of a species or group of species.0
4987705922Taxonomy- The classification and naming or organisms.1
4987705923Binomial Nomenclature- 2 part scientific naming format introduced by Carlos Linnaeus - 1st part- genus to which the species belongs. - 2nd part- specific epithet unique for each species. - Ex. Panthera pardus2
4987705924Linnaean System- Related genera. 1. Family 2. Order 3. Class 4. Phyla 5. Kingdom 6. Domain3
4987705925Phylogenetic tree- Branching diagram that represents the evolutionary history of a group of organisms. - Evolutionary relationships. - Has *branch points* that indicate the divergence of 2 evolutionary lineages from a common ancestor. - Shows patterns of descent. - Sequence of branching does not indicate the absolute ages of the particular species. - You cannot assume that a taxon evolved from the taxon next to it.4
4987705926Sister taxa- Groups of organisms that share an immediate common ancestor.5
4987705927Homologies- Phenotypic and genetic similarities due to shared ancestry. - Organisms with similar morphologies and DNA sequences are more likely to be related, although this is not always the case. - More elements similar in two complex structures- organisms might be homologous.6
4987705928Analogy- Similarity due to convergent evolution. - Ex. Bat's wings and bird's wings are analogous.7
4987705929Convergent Evolution- Occurs when similar environmental pressures and natural selection produce similar (analogous) adaptations in organisms from different evolutionary lineages.8
4987705930Homoplasies- Analogous structures that arose independently.9
4987705931Cladistics- Approach to systematics where common ancestry is the primary criterion used to classify organisms. - Organisms are grouped into clades10
4987705932Clades- Includes an ancestral species and all of its descendants. - Nested within larger clades.11
4987705933Monophyletic- A taxon that forms a clade since it consists of an ancestral species and all of its descendants.12
4987705934Paraphyletic- A group that consists of an ancestral species and some, but not all, of its descendants. - Most recent common ancestor of all members of the group is part of the group.13
4987705935Polyphyletic- A group which includes taxa with different ancestors. - Most recent common ancestor is not part of the group.14
4987705936Shared ancestral character- A character that originated in an ancestor of the taxon. - Ex. Backbone of mammals (predates the branching of mammals from other vertebrates)15
4987705937Shared derived character- An evolutionary novelty unique to a clade. - Ex. Hair (not found in all mammals)16
4987705938Outgroup- Used when inferring phylogenies - A species or group of species from an evolutionary lineage that is known to have diverged before the lineage that includes the species were are studying. - Can be determined by morphology, paleontology, embryonic development and gene sequences.17
4987705939Ingroup- Used when inferring phylogenies - The species that is being studied.18
4987705940Maximum parsimony- Principle that says one should first investigate the simplest explanation that is consistent with the facts when finding the most accurate phylogenetic tree. - Trees base don morphology → most parsimonious tree requires the fewest evolutionary events. - Based on DNA- most parsimonious tree requires fewest base changes.19
4987705941Molecular Clocks- An approach for measuring the absolute time of evolutionary change based on the observation that some genes and other regions of genomes appear to evolve at constant rates. - # of nucleotide substitutions in related genes is proportional to the time that has elapsed since the genes branched from their common ancestor. - Clock speed- many mutations are neither beneficial nor detrimental.20
4987705942From 2 Kingdoms to 3 Domains- Taxonomists once classified all species into 2 kingdoms: plants and animals. - 5 kingdoms recognized later: monera, protista, plantae, fungi, and animalia. - Prokaryotes separated from eukaryotes in Monera. - Problem: differences between prokaryotes can be drastic. - New 3 domain system: Bacteria, archaea and eukarya. - Bacteria: consists of prokaryotes - Archaea: consists of diverse group of prokaryotes - Eukarya: organisms with a nuclei.21

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