Quiz 2 Flashcards
Clade
a branch on an evolutionary tree
Phylogeny
The study of creating evolutionary trees
Carolus Linneaus
Time: 1707-1778
given credit for creating the modern system of scientific nomenclature
Describe the modern system of scientific nomenclature
-Two-part name called binomial
-The first part: genus, describes the group to which the organism belongs, always capitalized (first letter)
-Second part: species
Species epithet - applies to a single species within the genus
Taxonomy
the science of classifying and naming organisms
Taxon (plural:taxa)
generalized name for any taxonomic unit at any level of the hierarchy
Species
- any group of closely related organisms that can interbreed and produce fertile offspring
(prokaryotes don’t fit into this definition) - The basic unit of taxonomy (and evolution)
Populations
Members of the same species separated geographically into smaller groups are called populations
Taxonomic Hierarchy
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Robert Whittaker
Time - 1969
proposed a 5 kingdom system to distinguish organisms
Carl Woese
Time - 1970
hypothesized that prokaryotes fall into DOMAIN Bacteria or Archaea, and eukaryotes fall into Domain Eukarya (3 domain system widely accepted today)
Extant vs extinct
Extinct refers to a species that is no longer alive, extant means still alive
Tips vs nodes of an evolutionary tree
Tips - represent different taxa (often species)
Nodes - represent a speciation event from the common ancestor that gave rise to those taxa
Sister Taxa
Two descendants from the same node are called sister taxa
Topology
the branching pattern of the tree, represents the estimated evolutionary relationship among species
Morphology
the physical appearance of organisms
Convergent Evolution
ex: wings of a butterfly and wings of a bird both allow for flight, but the evolutionary origins are very different, case in point, the similar environment causes a need for the function/structure
Analogous features
Features that look and function similarly but come from different evolutionary origins
Homologous features
- Characteristics that appear similar and result from common ancestry are termed homologous,
Ex. All vertebrate animals have a vertebral column - Accurate phylogeny and classification system is based on these structures
Ingroup vs outgroup
group of organisms which you wish to estimate the evolutionary relationship of vs related to the others, but is assumed to have diverged from the rest earlier in the group’s evo history
Character vs character states
hair, blue hair vs red hair
Synapomorphies
shared derived traits
