Chapter 25 Vocab - Summary Campbell Biology PDF

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Ch 25 Definitions...

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Chapter 25: Phylogeny and Schematics Investigating the Tree of Life 

Phylogeny- the evolutionary history of a species or a group of species

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Systematics- analytical approach to understanding the diversity and relationships of organisms, both present-day and extinct

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Molecular Systematics- uses comparisons of DNA, RNA, and other molecules to infer evolutionary relationships between individual genes and even between entire genomes 25.1 “Phylogenies are based on common ancestries inferred from fossil, morphological, and molecular evidence” The Fossil Record

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Fossil Record- sequence in which fossils have accumulated in strata Morphological and Molecular Homologies Sorting Homology from Analogy

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Analogy- similarity between two species that is due to convergent evolution rather than to descent from a common ancestor with the same trait

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Homoplasies- similar (analogous) structure or molecular sequence that has evolved independently in two species 25.2 “Phylogenetic systematics connects classification with evolutionary history”

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Taxonomy- ordered division of organism into categories based on a set of characteristics used to assess similarities and differences

Binomial Nomenclature 

Binomial- the two-part Latinized name of a species, consisting of genus and epithet

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Genus- the first part of a species’ name, one above species in hierarchical classification

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Specific Epithet- the second part of a species’ name, unique for each species within the genus Hierarchical Classification

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Family- category above genus

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Order- category above family

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Class- category above order

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Phyla- category above class

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Kingdom- category above phyla

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Domain- category above kingdom

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Taxon- taxonomic unit at any level Linking Classification and Phylogeny

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Phylogenetic Trees- branching diagram that represents a hypothesis about evolutionary relationships

25.3 “Phylogenetic systematics informs the construction of phylogenetic trees based on shared characters” 

Cladogram- diagram depicting patterns of shared characteristics among species

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Clade- group of species that includes an ancestral species and all its descendants

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Cladistics- analysis of how species may be grouped into clades Cladistics

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Monophyletic - pertaining to a grouping of species consisting of an ancestral species and all its descendants, a clade

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Paraphyletic- grouping that consists of an ancestral species and some, but not all, of the descendants

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Polyphyletic- grouping of several species that lack a common ancestor Shared Primitive and Share Derived Characters

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Shared Primitive Character - character that is shared beyond the taxon that is trying to be defined

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Shared Derived Character - an evolutionary novelty unique to a particular clade Outgroups

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Outgroup- a species or group of species that is closely related to the ingroup

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Ingroup- the various species that is being studied Phylogenetic Trees and Lining Phylograms

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Phylogram- a phylogenetic tree in which the lengths of a branches reflect the number of genetic changes that have taken in a particular DNA or RNA sequence in the various lineages

Ultrametric Trees 

Ultrametic Tree- a phylogenetic tree in which the lengths of the branch reflect measurements of geologic time

Maximum Parsimony and Maximum Likelihood 

Maximum Parsimony- a principle that states that when considering multiple explanations for an observation, one should first investigate the simplest explanation that is consistent with the facts

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Maximum Likelihood- a principle that states that when considering multiple phylogenetic hypotheses, one should take into account of the one that reflects the most likely sequence of evolutionary events, given certain rules about how DNA changes over time 25.4 “Much of an organism’s evolutionary history is documented in its genome” Gene Duplications and Gene Families

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Orthologous Genes- refers to the homologous genes that are passed in a straight line from one generation to the next but have ended up in different gene pools because of speciation

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Paralogous Genes- genes that result from gene duplication, so they are found in more than one copy in the same genome

25.5 “Molecular clocks help track evolutionary time” Molecular Clocks

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Molecular Clock - a yardstick for measuring absolute time of evolutionary change based on the observation that some genes an other regions of genomes appear to evolve at constant rates Neutral Theory

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Neutral Theory- much evolutionary change in genes and proteins has no effect on fitness and therefore is not influenced by Darwinian selection The Universal Tree of Life

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Horizontal Gene Transfer - genes are transferred from one genome to another through mechanisms such as transposable elements, and perhaps through fusions of different organisms...