Phylogenies Flashcards
list the different levels of the taxonomic classification system**
describe how systematics and taxonomy relate to phylogeny**
what are the components of the phylogenetic tree**
distinguish between homologous and analogous characters**
Homologous structures share a similar embryonic origin and organisms that share similar physical and genetic features are more closely related than those that do not
analogous structures have similar functions, but different structures and embryonic origin
what is the difference between ancestral and derived traits**
ancestral trait: similarly that is found in the ancestor of a group (all of the organisms in the taxon or clade have that trait)
derived trait: character found only in one group
what is the purpose of cladistics**
Is a system of biological classification that sorts organisms into clades: groups of organisms that descended from a single ancestor.
describe the maximum parsimony**
a concept used to choose events that occurred in the simplest most obvious ways
why is phylogeny important **
Phylogeny
The evolutionary history and relationships of an organism or group of organisms
describes the relationships of the organisms, such as to which species it is most closely related
what does a rooted tree show?
show a single ancestral lineage
what does an unrooted tree show?
shows the relationships among species, not the common ancestor
what does a root indicate?
An ancestral lineage gave rise to all organisms on the tree
What is a branch point
the point where a split occurs. represents where a single lineage evolved/diverged into a distinct new one
What is a Basal Taxon
lineage that evolved early from the root and remains unbranched
What is a sister taxa
two sisters stemming from the same branch point
polytomy
a branch with more than two lineages. Shows where scientists have not definitively determined the relationships
What is systematics
is the scientific field that organizes and classifies organisms based on evolutionary relationships
** unless indicated, the branches do not account for the length of time, only the evolutionary order
what are the levels of classification
taxonomy: the science of classifying organisms on the basis of shared characteristics with each organism placed into increasingly more inclusive groupings
Linnaean system: is the taxonomic classification system
hierarchical: moving from the point of origin, the groups become more specific, until one branch ends as a single species
What are the 3 domains and the subcategories?
Bacteria, archaea, and eukarya
kingdom, phylum, class, order, family, genus, and species
What is a monophyletic group?
a single clade with shared traits
