The document discusses phylogeny and modern taxonomy. It explains that phylogenetic trees show how species are evolutionarily related, similar to how family trees show relationships between people. Phylogeny is the study of evolutionary relatedness among species. A clade represents all organisms that share a single common ancestor on a phylogenetic tree. Modern taxonomy overcomes issues with traditional taxonomy by comparing DNA samples to accurately determine identity and evolutionary relationships between specimens.

1. Phylogeny and Modern Taxonomy

2. Phylogeny
Humans have family trees that go back for many
generations to show our lineage and our ancestors.
These family trees show how 2 people may be related
to each other and by how many generations.

3. Phylogeny
Phylogenetic trees share the same idea as family
trees. They show how species have grown apart
(evolved) over time.

4. Phylogeny
Phylogenetic trees share the same idea as family
trees. They show how species have grown apart
(evolved) over time.

5. Phylogeny
Phylogeny: the study of the evolutionary relatedness
between and among species.

6. Phylogeny (Draw This)
A phylogenetic
tree is often
used to illustrate
these
relationships.

7. Phylogeny
Present
Branches
are
Many
Common
Years
Ancestors
Ago

8. Phylogeny: Clades
A clade is a branch of a phylogenetic tree that
represents all of the organisms that share a single
common ancestor.

9. Phylogeny: Clades
Clades can be any size, and occur at branches in
phylogenetic trees.

10. Phylogeny: Clades
Identify a
clade in this
tree.

11. Phylogeny: Clades

12. Phylogeny: Clades

13. Phylogeny: Clades

14. Phylogeny: Clades

15. Phylogeny: Clades

16. Phylogeny: Clades

17. Phylogeny: Clades

18. Phylogeny: Clades

19. Phylogeny: Clades

20. • To which other organism is Cervus elaphus
most closely related? At what rank and taxon
are they related?

21. Modern Taxonomy:
Think. Pair. Share
What are the drawbacks of traditional taxonomy?
- dichotomous keys may be ambiguous or subjective.
- following a dichotomous key takes time.
- mutations may lead to incorrect classification.

22. Modern Taxonomy:
Think. Pair. Share
What are the drawbacks of traditional taxonomy?
- different genetic structures may lead to similar
physical structures.
- evolutionary relatedness is only a guess using
physical features.

23. Modern Taxonomy:
Think. Pair. Share
How can all of these obstacles be overcome?

24. Modern Taxonomy
How can all of these obstacles be overcome?
By collecting and comparing DNA samples of specimens,
their identity and evolutionary relatedness can be
determined efficiently and accurately.

25. DNA Barcoding