Phylogeny terms

Terms used in Phylogeny

Binomial nomenclature

Genus then Species

Genus name

The group of species that share a recent common ancestor

Species name

The group of organisms that can mate and produce fertile offspring

Taxon

Any group of species that we designate with a name (e.g. vertebrates, carnivores)

Clade

A taxon that consists of all the descendants of a common ancestor

Sister species

Two species that are each other's closest relatives

Sister clades

Two clades that are each other's closest relatives

Homologous

Features that are shared by two or more species that were inherited from a common ancestor

Ancestral traits

Traits that are present in a common ancestor

Derived trait

Trait in a descendant that differs from the ancestral trait

Synapomorphies

Derived traits shared among a group; they are viewed as evidence of the common ancestry of the group

Convergent evolution

Independently evolved traits subjected to similar selection pressures may become superficially similar

Analogous

Functionally similar structures that have independent origins

Evolutionary reversal

A character reverts from a derived state back to the ancestral state

Homoplasy

Similar traits generated by convergent evolution and evolutionary reversals are called

Monophyletic

Contains descendants of only a single ancestor

Polyphyletic

Contains members that do not share the same common ancestor

Paraphyletic

Contains some but not all descendants of an ancestor

Phylogeny

The evolutionary history of relationships among organisms

Morphological - what it is

Looking at the structures found on and in an organism

Morphological - limitations

Some taxa show few morphological differences - It’s difficult to compare distantly related species - Some morphological variation is caused by environment

Development - what it is

Similarities in developmental patterns may reveal evolutionary relationships eg: tails in the womb

Behavioral - limitations

Some behaviors are passed down by the culture while others are inherited 

paleontology - what it is

Fossils can provide the forms of ancient species

paleontology - limitations

Fossil record is fragmentary and missing for some groups

In group

Group of primary interest

Out group

Compared to the in group

Plant family names end in

-aecae

Animal family names end in

-idae

Families are grouped into _____

Orders

Orders are grouped into _____

Classes

Classes are grouped into ___

Phyla

Phyla are grouped into _______

Kingdoms

Species are grouped into ____

Genus

Genus are grouped into _____

Families

Kingdoms are grouped into ____

Domains