Cornell Notes
Cladograms
Key Concept: A cladogram shows classification based on common
ancestors, and DNA shows species relatedness.
Questions/Main Ideas:
1. If you think of
yourself as the species,
who represents the
genus, family, and
order?
• Modern Classification is based on identifying evolutionary
relationships using the following:
o Evidence from living species
o Fossil record
o Molecular data
• The evolutionary history for a group of species is called
A phylogeny.
o Phylogenies can be shown as a branching tree.
o The branches of an evolutionary tree show how
different groups of species are related to each other.
2. What “derived
characteristics” are used
in this cladogram?
A cladogram is a diagram based on patterns of shared,
derived traits that show the evolutionary relationship
between groups of organisms.
Cladogram
3. Which animal may be
considered the
outgroup?
4. When might having
lungs be an advantage?
A species that has evolved a new trait is not better
than a species without that trait. Each species is just
adapted to a certain way of life.
Molecular evidence, such as certain DNA sequence, can be
used as a derived characteristic if it is shared among
certain groups of species.
5. Why does DNA often
have the “last word”
when scientists are
constructing
evolutionary
relationships?
Summary:
New Evolutionary Tree (Cladogram)