Principles of Life, Ch. 14 Reading

Families

are grouped into orders, orders into classes, classes into phyla (singular phylum), and phyla into kingdoms.

phylogenetic analysis

Any trait that is genetically determined, and therefore heritable, can be used in a(n) .

Linnaean classification

is based on standard taxon ranks.

evidence of evolutionary relationships

Derived traits provide .

Linnaean system

In the , species and genera are further grouped into a hierarchical system of higher taxonomic categories.

Parsimony

provides the simplest explanation for phylogenetic data.

Phylogenetic trees

depict evolutionary relationships among lineages.

Phylogenies

are reconstructed from many sources of data.

phylogenetic tree

A(n) may portray the evolutionary history of all life forms.

Phylogeny

The evolutionary history of a particular group of organisms or their genes

Phylogenetic Tree

A graphic representation of the lines of descent among organisms or their genes

Lineage

A series of populations, species, or genes descended from a single ancestor over evolutionary time

Taxon

A biological group (typically a species or clade) that is given a name

Clade

A monophyletic group made up of an ancestor and all of its descendants; Any taxon that consists of all the evolutionary descendants of a common ancestor

Homologous Features

A similarity between two or more features that is due to inheritance from a common ancestor; e.g

Ancestral trait

The trait originally present in the ancestor of a given group; may be retained or changed in the descendants of that ancestor

Derived trait

A trait that differs from the ancestral trait

Synapomorphies

A trait that arose in the ancestor of a phylogenetic group and is present (sometimes in modified form) in all of its members, thus helping delimit and identify that group

Convergent evolution

Independent changes to the same state or trait in two or more groups of organisms

Analogous

similar structures found in two or more groups of organisms, but with separate, independent evolutionary origins

Evolutionary reversal

The reappearance of an ancestral trait in a group that had previously acquired a derived trait

Homoplasies

The presence in multiple groups of a trait that is not inherited from the common ancestor of those groups

Ingroup

In a phylogenetic study, the group of organisms of primary interest

Outgroup

a group of organisms used as a point of reference for comparison with the groups of primary interest

Parsimony Principle

The principle that states that the preferred explanation of observed data is the simplest explanation

Morphology

The scientific study of organic form, including both its development and function; the presence, size, shape, and other attributes of body parts

Molecular clock

The approximately constant rate of divergence of macromolecules from one another over evolutionary time; used to date past events in evolutionary history

Binomial nomenclature

Phylogeny Is the Basis of Biological Classification

Genus

A group of related, similar species recognized by taxonomists with a distinct name used in binomial nomenclature

Monophyletic

Pertaining to a group that consists of an ancestor and all of its descendants

Polyphyletic

Pertaining to a group that consists of multiple distantly related organisms, and does not include the common ancestor of the group

Paraphyletic

Pertaining to a group that consists of an ancestor and some, but not all, of its descendants

Morphology

: The scientific study of organic form, including both its development and function; the presence, size, shape, and other attributes of body parts.

Monophyletic

: Pertaining to a group that consists of an ancestor and all of its descendants.

Ingroup

: In a phylogenetic study, the group of organisms of primary interest.

Polyphyletic

: Pertaining to a group that consists of multiple distantly related organisms, and does not include the common ancestor of the group.

Root

: In reference to phylogenetic trees: the base (oldest) part of the tree.

Phylogeny

: The evolutionary history of a particular group of organisms or their genes.

Molecular clock

: The approximately constant rate of divergence of macromolecules from one another over evolutionary time; used to date past events in evolutionary history.

Phylogenetic Tree

: A graphic representation of the lines of descent among organisms or their genes.

Homoplasies

: The presence in multiple groups of a trait that is not inherited from the common ancestor of those groups.

Convergent evolution

: Independent changes to the same state or trait in two or more groups of organisms.

Analogous

: similar structures found in two or more groups of organisms, but with separate, independent evolutionary origins.

Outgroup

: a group of organisms used as a point of reference for comparison with the groups of primary interest.

Homologous Features

: A similarity between two or more features that is due to inheritance from a common ancestor; e.g.

Lineage

: A series of populations, species, or genes descended from a single ancestor over evolutionary time.

Binomial nomenclature

: Phylogeny Is the Basis of Biological Classification.

Clade

: A monophyletic group made up of an ancestor and all of its descendants; Any taxon that consists of all the evolutionary descendants of a common ancestor.

Evolutionary reversal

: The reappearance of an ancestral trait in a group that had previously acquired a derived trait.

similar species

Genus: A group of related, recognized by taxonomists with a distinct name used in binomial nomenclature.

This application of parsimony is a specific case of a general principle of reasoning called Occams razor

the best explanation is the one that best fits the data while making the fewest assumptions