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Cladistics
CLADISTICS IS CLASSIFICATION BASED ON
COMMON ANCESTRY.
 Phylogeny
is the evolutionary history for a group of
species.
 Supported by evidence from living species, fossil
record, and DNA
 Shown with branching tree diagrams
Species placed in order that they
descended from a common ancestor
Clade: is a group of species that shares a
common ancestor.
– Each species in
a clade shares
some traits
with the
ancestor.
– Each species in
a clade has
traits that
have changed.
Derived characteristics are traits shared
by clade members
– Determine how
species are
arranged on a
cladogram
– More closely
related species
share more
derived
characteristics
– Represented on
cladogram as
hash marks
1 Tetrapoda clade
2 Amniota clade
3 Reptilia clade
4 Diapsida clade
5 Archosauria clade
FEATHERS &
TOOTHLESS
BEAKS.
SKULL OPENINGS IN
FRONT OF THE EYE &
IN THE JAW
OPENING IN THE SIDE OF
THE SKULL
SKULL OPENINGS BEHIND THE EYE
EMBRYO PROTECTED BY AMNIOTIC FLUID
FOUR LIMBS WITH DIGITS
DERIVED CHARACTER
•Nodes
represent
the most
recent
common
ancestor
of a clade.
CLADE
1 Tetrapoda clade
2 Amniota clade
3 Reptilia clade
4 Diapsida clade
5 Archosauria clade
FEATHERS
AND
TOOTHLESS
BEAKS.
SKULL OPENINGS IN
FRONT OF THE EYE
AND IN THE JAW
OPENING IN THE SIDE OF
THE SKULL
SKULL OPENINGS BEHIND THE EYE
EMBRYO PROTECTED BY AMNIOTIC FLUID
NODE
FOUR LIMBS WITH DIGITS
DERIVED CHARACTER
How to make a Cladogram Video:
 http://www.youtube.com/watch?v=ouZ9zEkxGWg
