Cladogram construction Given a table of derived characters, create a cladogram

Step Two – Convert the Venn Diagram into a Cladogram Kangaroo Bullfrog Human Shark Placenta Mammary Glands Two pairs of limbs Vertebrae

How are cladograms constructed? Organisms are grouped together based on their shared derived characteristics.

Evidence for Evolution Evidence from the fossil record- comparing fossils from older & younger rock layers documents the fact that evolution has occurred; it is a detailed record of evolution. 2. The geographical distribution of species-the presence of similar environments suggests natural selection. Ex.-the finches could have descended from common ancestors on the mainland. 3. Homologous structures- they have different mature forms but develop from the same embryonic tissues. Bone structure is the same but they look different. All are adapted to survive in different environments. Ex. Legs, wings, fins. Vestigial organs- some homologous structures no longer serve important functions in descendants. Their size is reduces. 4. Similarities in embryology- early stages, or embryos, of many animals are very similar. 5. DNA evidence

DNA Evidence

Homologous Structures Example: the wing of a bat, the flipper of a dolphin and the hand of a human all have five ‘fingers.’ These structures despite having completely different functions are similar because they all come from the common ancestor of all mammals.

Analogous Structures Example: the wing of a bat and the wing of an insect both serve the same function (to allow the organism to fly) but they come from very different evolutionary origins. Bat wings are made of bones and skin, insect wings have neither.

Analyzing Geological and Environmental Changes On standardized exam you may be asked to analyze changes over time. Analyze the fossil layers to the right and explain what happen to the area. NOTE: Play close attention to the arrow to the right. (Shows the direction of the time line)

Analyze the evolution of the horse Analyze the evolution of the horse. List various changes that took place in each column.

Directional Selection

Stabilizing Selection

Disruptive Selection