Ch 2 Flashcards
Systematics
“It is the science of classification and reconstructions of phylogeny. STUDY OF CLASSIFICATION
Taxonomy
“taxa” - arrangment
“nomos” - law
-applying names to each of the different kinds of organisms
PRACTICE/LAWS OF CLASSIFICATION
population
group of organisms of the same species sharing a particular space
Species
Similar and related populations
Species (not individuals) are basic units of systematics & basis of classification
Viviparous
producing living young (not eggs) that develop within the mother’s body.
Oviparous
egg-laying
Biological Species Concept
Species are groups of interbreeding natural populations that are reproductively isolated from other such groups
Genus
A group of closely related species or a group of species that have descended from a common ancestral group.
Monophyletic
Contains the most recent common ancestor of the group and ALL the descendants
Paraphyletic
Contains most recent common ancestor of the group but NOT ALL of the descendants
“para-“ = alongside, beside
Polyphyletic
Does NOT contain the most recent common ancestor of all members of the group, implying multiple evolutionary origins
“poly-“ - many; multiple
“phyl-“ or “phylo-“
tribe; clan
What was Aristotle’s Classification system known as?
“A and not-A
The “A” Group - Animals w/ blood
(Viviparous/Oviparous quadrupeds, Fishes, Birds)
The “Not-A” Group - Animals w/o Blood
(Mollusk, Crustaceans, Testaceans, Insects)
Before what year are all binomials published no considered invalid? Why?
1758; Linnaeus published his 10th ed of Systema Naturae which established the foundation for the binomial nomenclature
When was the Origin of Species published? By whom?
Darwin in 1859
What is Phenetic Classification
It is numerical classification which expanded in 1960’s. It argues that organisms should be classified by phenotypic (structural) characteristics even if it did not reflect the evolutionary history.
Does not strive to reflect lineages but rather “clumps” together organisms based on “overall” similarities
Cladistics
systemic method that focuses on shared, derived traits. Recognizes only MONOphyletic taxa
What are the 3 types of shared derived traits?
Synapomorphies
Plesiomorphy
Symplesiomorphies
Synapomorphies
shared derived characteristics (shared by living organisms inherited from recent common ancestors
Plesiomorphies
shared ancestral characteristics (primitive traits inherited from an ancestor)
Symplesiomorphies
primitive traits shared by larger groups (inherited from an ancient common ancestor) that do not impart cladistic value
