the evolutionary history of a species or group of species
a discipline focused on classifying organisms and determining their evolutionary relationships
how organisms are named and classified
is the two part format of the scientific name of an organism. The first part is the name of the genus to which the species belongs. The second part, called the specific epithet, is unique for each species within the genus.
the named taxonomic unit at any level of the hierarchy
the evolutionary history of a group of organisms can be represented in a branching diagram.
only names groups that include a common ancestor and all of its descendants
groups of organisms that share an immediate common ancestor and hence are each other’s closest relatives
which means that a branch point within the tree (often drawn farther to the left) represents the most recent common ancestor of all taxa in the tree
refers to a lineage that diverges early in the history of a group and hence lies on a branch that originates near the common ancestor of the group.
a branch point from which more than two descendant groups emerge.
the discipline that uses data from DNA and other molecules to determine evolutionary relationship
common ancestry is the primary criterion used to classify organisms
using cladistics biologists attempts to place species into this group each of which includes an ancestral species and all of its descendants
consists of an ancestral species and all of its descendants
paraphyletic-consists of an ancestral species and some but not all of its descendants or a polyphyletic (many tribes) group which includes taxa with different ancestor.
shared ancestral character-
a character that originated in an ancestor the the taxon example for mammals the backbone.
shared derived character-
an evolutionary novelty unique to a clade example: hair is a character shared by all mammals but not found in their ancestors.
is a species or group of species from an evolutionary lineage that is known to have diverged before the lineage that includes the species we are studying (the ingroup)
states that given certain probability rules about how DNA sequences change over time, a tree can be found that reflects the most likely sequence of evolutionary events
are those found in different species and their divergence traces back to the speciation events that produced the species
the homology results from gene duplication; hence multiple copies of these genes have diverged from one another within a species
a yardstick for measuring the absolute time of evolutionary change based on the observation that some genes and other regions of genomes appear to evolve at constant rates.
that much evolutionary change in genes and proteins has no effect on fitness and therefore is not influenced by natural selection.
horizontal gene transfer-
a process in which genes are transferred from one genome to another through mechanisms such as exchange of transposable elements and plasmids, viral infection, and perhaps fusions of organisms.