17 2 Classification Based on Evolutionary Relationships KEY

17. 2 Classification Based on Evolutionary Relationships KEY CONCEPT Modern classification is based on evolutionary relationships.

17. 2 Classification Based on Evolutionary Relationships Cladistics is classification based on common ancestry. • Phylogeny is the evolutionary history for a group of species. – evidence from living species, fossil record, and molecular data – shown with branching tree diagrams

17. 2 Classification Based on Evolutionary Relationships • Cladistics is a common method to make evolutionary trees. – classification based on common ancestry – species placed in order that they descended from common ancestor

17. 2 Classification Based on Evolutionary Relationships • A cladogram is an evolutionary tree made using cladistics. – A clade is a group of species that shares a common ancestor. – Each species in a clade shares some traits with the ancestor. – Each species in a clade has traits that have changed.

17. 2 Classification Based on Evolutionary Relationships • Derived characters are traits shared in different degrees by clade members. 1 Tetrapoda clade – basis of arranging species in cladogram – more closely related species share more derived characters – represented on cladogram as hash marks 2 Amniota clade 3 Reptilia clade 4 Diapsida clade 5 Archosauria clade FEATHERS & TOOTHLESS BEAKS. SKULL OPENINGS IN FRONT OF THE EYE & IN THE JAW OPENING IN THE SIDE OF THE SKULL OPENINGS BEHIND THE EYE EMBRYO PROTECTED BY AMNIOTIC FLUID FOUR LIMBS WITH DIGITS DERIVED CHARACTER

17. 2 Classification Based on Evolutionary Relationships • Nodes represent the most recent common ancestor of a clade. CLADE 1 Tetrapoda clade 2 Amniota clade 3 Reptilia clade • Clades can be identified by snipping a branch under a node. 4 Diapsida clade 5 Archosauria clade FEATHERS AND TOOTHLESS BEAKS. SKULL OPENINGS IN FRONT OF THE EYE AND IN THE JAW OPENING IN THE SIDE OF THE SKULL OPENINGS BEHIND THE EYE EMBRYO PROTECTED BY AMNIOTIC FLUID NODE FOUR LIMBS WITH DIGITS DERIVED CHARACTER

17. 2 Classification Based on Evolutionary Relationships Molecular evidence reveals species’ relatedness. • Molecular data may confirm classification based on physical similarities. • Molecular data may lead scientists to propose a new classification. • DNA is usually given the last word by scientists.

17. 2 Classification Based on Evolutionary Relationships 1 st period grouping (partner groups) Mack Hannah Ashley Kima Vivek Cara Leen Mc. Kenzie Chezion Tyanna India Robert Thomas Trinity Cole Savannah Mattie Ethan Thomas Lucy Liberty Bailey Kayla Naderah Josie Evan Elise Justin *David

17. 2 Classification Based on Evolutionary Relationships 2 nd period groups Selena/Litzy Jordan Alyssa Luke Katie Suhas Keelan Josh Armani Christian Brooke Ashlyn Sawyer Katelyn Austin Mathew Jonathan Erin Keely Kenzie Brady Colton Kayla Jade Payton Madison Gavin Dante Micah Noah *Litzy

17. 2 Classification Based on Evolutionary Relationships 3 rd Period Marcus Trinity Hannah Garrett Haley Jay Heaven/Ryan Nick Tyler Malcolm Nykiah Dylan Bayley Blake Brandon Sophie Miles Alianna Reece Jayda Angel Anthony