Bio1100
Chapter 12
The origin and diversification of life on earth
Carolus
Linnaeus
introduced a system of
classification
for grouping and naming similar organisms in
hierarchical
categories.
Classification should reflect
phylogeny
, the
evolutionary
history of
organisms
based on descent from a
common
ancestor
.
Phylogeny should reflect changes in
DNA
as organisms
evolve
.
Current classification groups life into
three
domains
.
Species can arise by
allopatric
or
sympatric
speciation
.