Chapter 26 Flashcards
Phylogeny
is the evolutionary history of a species or group of related species
Phylogenetic tree
diagram depicting evolutionary history of species
Systematics
a discipline focused on classifying organisms and determining their evolutionary relationships
involves reconstruction and study of phylogenetic trees
Classification
is multilevel grouping of organisms based on their similarities and differences
Taxonomy
the science of classifying organisms into hierarchical groupings
includes assigning scientific names
Binomial System
two part naming system
Acer rubrum
North American red maple
Felis domesticus
Domestic cat
Streptoccocus pyogenes
Strep throat bacterium
Bacillus anthracis
Anthrax bacterium
Saccharomyces cerevisiae
Baker’s yeast-fungus
Giardia lamblia
Protozoan parasite-protist
Myotis macrotarsus
mouse-eared bat with big feet
Stachytarpheta jamaicensis
herbaceous shrub in Jamaica
Escherichia coli
named after German bacteriologist Theodor Escherich
Culex molestus
habit of sucking blood (molesting) of host at night time
Who came up with the Binomial/Linnaean System?
Carolus Linnaeus
Binomial System
a system of taxonomy based on resemblances
First part of Binomial System
Genus covers a group of related species (only first letter is capatilized)
Second part of Binomial System
specific epithet identifies one species within that Genus (not capatilized)
7 basic taxa levels
kingdom
phylum
class
order
family
genus
3 domain system
Bacteria
Archaea
Eukarya
Panthera pardus
species classification
Classification and Phylogeny
the evolutionary history of a group of organisms can be represented in a branching diagram called a phylogenetic tree
What we can learn from phylogenetic trees
it represents a hypothesis about evolutionary relationships, each branch point represents the divergence of two evolutionary lineages from a common ancestor, an evolutionary lineage is a sequence of ancestral organisms leading to a particular descendant taxon, sister taxa are groups that share a common ancestor that is not shared by any other group
What we cannot learn from phylogenetic trees
they show patterns of descent not phenotypic similarities, they do not indicate when species evolved or how much change occurred in a lineage, should not be assumed that a taxon evolved from the taxon next to it
Cladistics
approach in phylogeny where clades are identified
Cladogram
monophyletic branching diagram
Clade
a group of species that includes an ancestral species and all its descendants
Shared primitive characters
a character that originated in an ancestor of the taxon
Shared derived characters
an evolutionary novelty unique to a particular clade
Outgroup organisms
a species or group of species closely related to, but not part of the group of species being studied
Ingroup organisms
compared with the outgroup to differentiate between shared derived and shared ancestral/primitive characters
Monophyletic group
consisting of 3 species and their common ancestor
Paraphyletic group
consists of ancestral species and some of its descendants
Polyphyletic group
consisting of four species, the most common recent ancestor is not part of it
Branch length
reflects the number of genetic changes that have occurred in each lineage
