A New System of Classification _____________: A New System of Classification What is it? The _____________________of a species. What is the Goal? To show the ___________ between different species. 2. To _________ common ancestors

and even further… Phylogeny is based on *____________*. ______________ – the systematic grouping of species based on shared characteristics. Charlemagne … … … That’s me!! Using mitochondrial DNA we can trace my ancestors back to Charlemagne… and even further…

We are all basically right here! …back to ALL HUMANS!

…back to ALL Primates!

…back to ALL MAMMALS

…back to ALL Vertebrates

…and back to ALL Animals!!!

They show who is most closely related to whom. Those who I am most closely BRANCHED to is who I am most closely related to! __________, like family trees, depict relationships. They are simple, branching diagrams. They show who is most closely related to whom. See! If you turn my tree sideways… That’s me!! These “branches” are called __________! A _______ is where a change is observed. So, the fewer changes that occur between me and the next ancestor, the more closely related I am to them.

__________ – groups of organisms defined by shared characteristics! Observe the nodes here. Good Cladograms (that’s what these are called) will usually have an “__________” that indicates the ancestor.

Amnion Vertebrate Jaws 2 Pairs of Appendages! With a little help from the labels, what do these NODES mean?

So… how are these Cladograms The “Indiana Jones” way… constructed? The high tech way.. Some really nerdy, but very cool genetics folks look at DNA VERY closely. Wherever they see a change (mutation) that significantly separates them from their parents, a node is created. The “Indiana Jones” way… Fossils are studied and the Phenotypes are compared!

Does this give us DEFINITIVE PROOF of macroevolution?? Not quite, but it does give us a nice foothold from which we can start experimenting from. In other words, Cladograms give us a HYPOTHESIS to start with!!

Mammals! Primates! Chordates! German! ME! Humans!

Key Points to Remember!! Phylogeny – A Genetic Evolutionary tree used to compare and study life’s history Clades – Groups that are together because they share common characteristics Node – a ‘branch’ in the phylogeny tree indicating a new, significant difference. This difference has been noted because of genetic studies or phenotypical differences discovered by archaeologists. These trees are pieced together as Hypothesis to our evolutionary history. It gives us good places to start our investigations.