Test 2 Review - Test 2 Review Chapter 25 Phylogenetics Evolutionary history of a species or group of species Systematics an analytical approach to

Test 2 Review - Test 2 Review Chapter 25 Phylogenetics...

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Test 2 ReviewChapter 25Phylogenetics- Evolutionary history of a species or group of speciesSystematics- an analytical approach to understanding the diversity and relationships o organisms, both present-day and extinctStudies both extinct and extant (living)Connects classification with evolutionPhylogenies- In order to construct these biologists draw on the fossil records which provides information about ancient organismsConvergent Evolution- Similar environmental pressures and natural selection produce similar adaptations in organisms from different evolutionary lineagesHomologies- Similarity in characteristics resulting from a shared ancestryHomologous Traits- traits in different species that are similar because of common ancestryAnalogous Traits- Similar traits between two species that is due to convergent evolution rather than to descent from a common ancestor with the same traitPhylogenetic systematics- Taxonomy- Categorizing VariationD K P C O F G S o i h l r a e pm n y a d m n ea g l s e i u ci d u s r l s in o m y em sBinomial Nomenclature- the two-part format of the scientific nameHomoSapienHierarchy of classification- The order in which categorizing occursPhylogenetic Tree- Depicts hypotheses about evolutionary relationshipsReflects the hierarchical classification of groups nested within more inclusive groups
Cladogram- If the shared characteristics are due to common ancestry then it forms the basis of a phylogenetic treeClade- a group of species that includes an ancestral species and all its descendantsCladistics- The analysis of how species may be grouped into cladesMonophyletic- A valid clade that consists of the ancestral species and all its descendantsParaphyletic- a lack of information about some members of a clade that consist of an ancestral species and some, not all, of the descendantsPolyphyletic- a grouping of several species that lack a common ancestorPrimitive character- a character that is shared beyond the taxon we are trying to defineDerived character- an evolutionary novelty unique to a particular cladeParsimony (Occam’s Razor)- solving an approach by “shaving away” unnecessary complicationsChapter 26Protobiont- Aggregates of abiotically produced molecules surrounded by a membrane or membrane-like structureRibozyme- RNA, which plays a central role in protein synthesis, can also carry out a number of enzyme-like catalytic functionsCan make complementary copies of short pieces of RNAoMust be supplied with nucleotide building blocksEndosymbiosis- Protobionts self-replicating RNA and DNA to create eukaryotes and ultimately multicellular eukaryotesPrecambrian Era:All marine, aquaticEukaryotes evolve- 2 B.Y.AMulticellular eukaryotes evolved 800-700 M.Y.A650-550 M.Y.A. see simple multicellular organismFirst invertebrates 550 M.Y.ACambrian Era:542-488 M.Y.A.

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