3. The Monophyly Snip RuleSnip below a node, what falls off is a monophyletic group

The Monophyly Rule and Taxonomy

No birds!

Not very PC*!*(phylogenetically correct)

“PC”, Phil Ward, UC Davis

Breaking the Monophyly Rule in Taxonomy

Non-PC Names*:Algae (land plants are excluded)Crustaceans (insects are excluded)Moths (butterflies are excluded)Wasps (ants and bees are excluded)Reptiles (birds are excluded)

•* “Non-Phylogenetically Correct”, Phil Ward, UC Davis

4. Sibling ≠ AncestorA common question: If humans evolved from chimps, why are there still chimps today?

Swivel the node. Did chimps evolve from humans?

Why are there still other primates?What is U? Will paleontologists find it?

5. Sister lineage snip rule and ages

One point in time

Time A Time B

** Snip just above a node and what falls off are sister lineages (sister taxa)

•Time A = Time B•Both lineages have been evolving for the same amount of time•Sister lineages have = ages

Q R

•Fish were present in the fossil record first, but that lineage didn’t “stop evolving”•Modern fish are just as “highly evolved” for what they do as humans are for what we do•Fish and humans have been evolving for the same amount of time since their common ancestor

Don’t be fooled by long branches (the focus of the tree may be misleading at first glance)

This tree may look odd, but it is correct

Long branches/tree imbalance

At first glance: Monotremes and Marsupials may seem more “primitive” than the other mammals (Placentals)

That appearance is (in part) due to tree “imbalance”

3 living species (poor diversity)

250 living species (poor sampling)

Age Rule (Modern Taxa Are Not Primitive): Don’t be fooled by branches on the left

Don’t be fooled by long branches

What is “primitive” on this tree?

Early mammal—laid eggs, but not an echidna or platypus

Reconstruction of Megazostradon, the earliest fossil mammal

The duck-billed platypusModern mammal, some primitive characters

Many characters not seen in mammalian ancestor:“Bill”, electro-receptors, venom (not the same kind as reptiles)

Primitive character state