Systematics
the science that studies the evolutionary relationship among species (or groups of species)
Taxonomy
the part of systematics that deals with the practice of describing, identifying, and classifying species
“a kind of sort”
the meaning of the Latin speci that species comes from
forensics; public health and medicine; wildlife management; baseline for comparative research; understanding the evolution of specific characteristics; phylogeography
uses of systematics
Biological Species Concept (BSC)
“species are groups of actually or potentially interbreeding natural populations, which are reproductively isolated from other groups” – considered populations of the same species if they can reproduce and produce fertile and viable offspring
asexually reproducing organisms; fossils; hybrids (common in plants)
exceptions to the Biological Species Concept
phylogenetic tree
diagram that depicts the lines of evolutionary descent of different species, organisms, or genes from a common ancestor
Linnaeus
Swedish scientist (1700s) who invented system of classification in biology
Binomial nomenclature and hierarchical classification
the two classifications of species
Binomial classification
2 names: Genus epithet
ex: Homo sapiens
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Hierarchial classification
Phyla
plural of Phylum
Genera
plural of Genus
characters
characteristics or traits
anatomy/anatomical features; nucleic acid sequences; behavior (song patterns, etc)
kinds of characters that can be used to identify species
Homology
similarity based on common ancestry
developmental homolgy
similairites between species in embryonic stage
molecular homology
genes inherited from common ancestor, similar sequences in same order on chromosomes
Analogy
the result of convergence; similarity not based in common ancestry
Homoplasy
an analogous trait
independent acquisition; reversal
kinds of homoplasy
analogous; homologous
bat wings and bird wings are _______ traits while bat arm/finger bones and bird arm/finger bones are ________ traits
analogous; independent acquisition/convergent evolution
the common dolphin and ichthyosaur have _______ traits that are from _/
phylogenetic trees (cladograms)
Hypotheses of evolutionary relationships
node
speciation event
unresolved node
uncertain relationship
internode
common ancestor
sister group
closest relative
phylogeny
classifications should be based in __________
monophyletic
group/taxa that includes all the descendants and their most recent common ancestor
paraphyletic
group/taxa that includes most recent common ancestor but not all descendants
polyphyletic group/taxa
group/taxa that does not include common ancestor
synapomorphy
shared derived (evolved later from other trait) character
plesiomorphy
shared ancestral trait