Quick Questions What are the two main criteria that all members of a species share? Rana temporaria is a frog commonly found in Britain. Complete the table below by giving the most appropriate name for each of the numbers 1 – 7: Kingdom Animalia 1 Chordata 2 Amphibia 3 Anura 4 Ranidae Genus 5 6 7

Answers Observable similar characteristics ability to reproduce to create fertile offspring 2. Kingdom Animalia Phylum Chordata Class Amphibia Order Anura Family Ranidae Genus Rana Species temporaria

Difficulties in Defining a Species

What is phylogeny?

What is phylogeny? The grouping of organisms to show the historical, evolutionary relationships between them. From ‘phylum’ Drawn as a phylogenetic tree (cladogram) – closer the branches, the closer the evolutionary relationship

What is phylogeny? Comparative anatomy – look at homologous structures Anatomical structures that have a similar evolutionary origin and development in the body Indicates evolution from common ancestor

Drawing Cladograms Produces eggs 4 Opposite appendages Placental mammal 4 chambered heart Flippers Sea Star X Cow Emus Salamander Blue Whale

Interpreting Cladograms 1.) The root of the phylogenetic tree is closest to which node? 2.) The common ancestor for species E and D can be found at which node? 3.) The common ancestor for species B and D can be found at which node? 4.) The common ancestor for species C and A can be found at which node? 5.) Which node represents the common ancestor of all species on the tree? 6.) Which two species share the most recent common ancestor (i.e. are most closely related)?

Interpreting Cladograms 1.) The root of the phylogenetic tree is closest to which node? 3 2.) The common ancestor for species E and D can be found at which node? 1 3.) The common ancestor for species B and D can be found at which node? 4 4. The common ancestor for species C and A can be found at which node? 3 5.) Which node represents the common ancestor of all species on the tree? 3 6.) Which two species share the most recent common ancestor (i.e. are most closely related)? C and B

Drawing a Cladogram Use the information on the handout to complete the table by drawing a ‘x’ if an organism has a certain trait Then draw a venn diagram to sort out the groups If an animal only has one trait, it would be in the largest box. If it has all the traits, it would be in the smallest, centre box. Then draw and label a cladogram of the organisms