Cladistics (20-3) Notes Sheet
name:__________
cladogram:
Uses shared derived characters to:
 ____________________________________________
 ____________________________________________
A clade is an ____________________________________________
 ____________________________________________
 ____________________________________________
Notice in the chart on the
right _____________________
_________________________
_________________________
_________________________.
lizard
snake
newt
Fig 20.11 a
eel
When constructing a
cladogram, _______________
_________________________
_________________________
_________________________
lancet
Constructing a Cladogram
Notochord in embryo
Vertebrae
Lungs
Three-chambered heart
Only the newt, snake and
lizard _________________
_______________________.
Internal fertilization
Amniotic membrane in
egg
Snakes and lizards ______
_______________________
_______________________.
Four bony limbs
long cylindrical body
Reptiles (snakes and lizards) are a clade
Clade: ____________________________________________________________________
__________________________________________________________________________
The newt (an amphibian) and the eel (fish) _____________________________________.
The next step is to _________________________________________________________.
The goal is to _____________________________________________________________.
What is the deal then with bony limbs and long cylindrical body?
parsimony: _________________________________________________________________
Cladists are always guided by ______________
 The arrangement ____________________
___________________________________
 This would:
 ______________________________
______________________________
 ______________________________
______________________________
The reliability of a cladogram is dependent on
the knowledge and skill of the investigator
How do these two cladogram differs? What assumptions would be made to make the
difference between a. and b.?
Phenetic Systematics
Assumes it will never be possible to construct a truly phylogenetic classification system
Species are classified ___________________________________________________
 Disregards __________________________________________________
 Ignores _____________________________________________________
Traditional Systematics
Mainly uses anatomical data
 Classify organisms using ____________________________________________
 Stress both common _________________ and ____________________________
___________________________________
 Construct phylogenetic trees by applying ________________________________

Not strict in making sure all _______________________________