bio112 exam2

a similar structure, similar development, or similar genetics among organisms that exist because they share a common ancestor

remnants of structures inherited from a common ancestor, that no longer serves a clear function in the organisms

study of geographic distribution of species (living and extinct)

• organisms have similar characteristics even though they are not closely related but instead they have evolved similar adaptations because they occupy similar nitches
• 2 different species from 2 different lineages independently evolved similar characteristics because they occupy simlar environments

• the process of describing, naming, and classifying extant organisms
• those that are living today

• a field of study that examines the biological diversity and evolutionary relationships among organisms, both extant and extinct
• focus is on pattern and process
• based on homology

• the evolutionary history of a species (or group of species)
• use the tools of systematics to propose a phylogeny

a diagram that describes the evolutionary relationships among species based on information gathered by systematists

hypothesis that is proposed, tested, and refined

• a taxon that is a clade
• what we are aiming for
• ex mammals

a group that contains a common ancestor and some (but not all) of its descendants

a group that does not contain the most recent common ancestor

• compare homologous traits = character
• each character/trait can exist on 2+ character states

• most mutations are neutral
• they have no impact on the organism, if neutral mutations occur at a relatively constant rate, can use them as a clock to measure evolutionary time

the splitting or diverging of a population into 2 species

 or monophylum is a group consisting of an ancestor and all its descendants, a single "branch" on the "tree of life

shared/together traits

• a derived character
• A novel evolutionary trait that is unique to a particular species and all its descendants and which can be used as a defining character for a species or group in phylogenetic terms.

• shared-primitave trait
• In cladistics, a symplesiomorphy or symplesiomorphic character is an ancestral trait shared by two or more taxa. A plesiomorphy refers to the ancestral trait on its own, usually in reference to another, more derived trait.

In cladistics, itis a distinctive anatomical feature, known as a derived trait, that is unique to a given terminal group. That is, it is found only in one member of a clade, but not found in any others or outgroup taxa, not even those most closely related to the group

a character that is shared by species beyond the taxon of interest

a character (feature) shared by all the species in a group but not by any species outside that group synonym: synapomorphy