Chapter 26 Flashcards
systematics is the study of
the diversity of relationship among organisms
systematics consists of
- taxonomy
- phylogenetic
taxonomy consists of
- binomial nomenclature
- hierarchical classification
the goal of phylogentics is to determines
phylogenies
____________ is the evolutionary of a species or larger taxonomic
phylogeny
two ways phylogenies are determined
- fossil record
- morphological, developmental, and molecular similarities
is a large but incomplete chronicle of evolutionary change over the scale of geologic time
fossil record
similarities useful for deducing evolutionary history and relationships among extant organisms
-morphological, developmental, and molecular similarities
_________________ are similarities due to common ancestry
homologies
three type of homologies
- morphological
- developemental
- molecular
when two species share all three types of homologies, phylogeneticists are most confident that the species descend from a recent common ancestor and are therefore
closely related
(also known as homoplases) are similarities due to convergent evolution rather than to common ancestry
analogies
occurs when natural selection, due to the same environmental pressure produces similar adaptions in organisms that are not closely related
convergent evolution
___________________ can be distinguished from analogy by comparing several different characteristics as well as the degree of complexity
homology
molecular homologies can be easily obscured and molecular analogies can be easily misinterpreted as
homologies
_____________________________ have been developed to distinguish between molecular homologies and analogies
computer programs and statistical analysis
_________________ are used to depict phylogenies
phylogenetic trees
_________________ contains a common ancestor and all descendants of that ancestor
a monophyletic group
__________________ contains a common ancestor but not all of the descendants
a paraphyletic group
only _____________ are recognized as true taxonomic group
monophyletic groups
monophyletic groups are also called _________
clades
the current approach to phylogenetic which only recognizes class as valid taxa is called
cladistics
using the cladistic approach, phylogenetic tree are also called
cladograms
_______________ are traits possessed by particular taxa
characters
character are placed on the _____________ of a particular taxa
branch
_____________________ indicates when that trait evolved
the placement of a character
a _________________ is a shared primitive ancestral character
symplesiomorphies
represent the unity of life and descent from common ancestry
symplesiomorphies
a ________________ is a shared derived character unique to individual
synapomorphies
__________________ represent the diversity of life and modifications from common ancestry
synapomorphies
_________________ is a group of organisms (the clade) specifically being studied
in-group
_____________________ is a closely related taxon to the in-group, but not as closely related as all members of the in-group are to each other
outgroup
the inclusion of an outgroup confirms that the
synplesomorphies of the group are synapomorphies
when determining among multiple possibilities for a particular phylogeny begin with the
simplest explanation
the goal of systematics is for
classification to represent phylogeny
phylogenetic is currently showing many traditional classifications to be incorrect
- phylum chordata
- class reptillia
- class aves
crocodiles and bird share 3 trades
- attract mates by singing
- building nests
- brood their eggs
archaea is most closely related to ___________ domain
eukarya
____________ an unresolved node
polytomy
class of reptillia is a _______________
paraphyletic group
