Bellwork: Copy the bolded words and your answer choice The concept of gene flow is demonstrated when a cow is driven off from its herd, joins another herd, and reproduces. When the cow contributes to the gene pool of the new herd, which of these most likely increases? Natural selection Genetic variation Environmental fitness Reproductive mutations

Science Fact of the Day: The Giant Kelp algae (Macrocystis pyrifera) is the fastest growing organism on earth and can grow at a rate of 70cm (two feet) a day.

Science Fact of the Day: Rafflesia Arnoldii is the largest flower in world, and can grow as big as an umbrella.

Evidence of Evolution Homologies Fossil Record Biogeography Anatomical Molecular Embryonic

Fossil Record Fossil: The evidence in rock of the presence of a plant or an animal from an earlier geological period *further down = older (usually) *carbon dating can help determine age *transitional fossils can show evolutionary changes *incomplete

Types of Fossils

How Fossils form

The picture to the right shows a series of major Biological Events that have taken place over the last 488 Million Years! Biologists were able to piece these events together based on evidence collected from fossils. Take notice of the extinctions. What happened immediately after each one?

Carbon Dating is a method widely used to date fossils to find out where they lie on the evolutionary timeline. Take a look at the graph. It shows how the percent of carbon-14 remaining in a sample indicates the age of the sample. What would the age of a bone be if it contained only 10% of Carbon-14? What percent of Carbon-14 would you expect to find in a sample that is 7580 years old?

According to the table, if ¼ of the original radioactive carbon is present in a fossil, what is the fossil’s age? Which Isotope would be best for measuring the age of a rock layer estimated to be about one million years old?

Homework tonight: Cladograms by Bozeman Science Cornell Notes plus you MUST draw the cladogram

Cladograms = diagrams that we use to show phylogenies A phylogeny = evolutionary history *show relationships *use evidences of evolution *can be changed with new data

How do you build a cladogram?

Step 1: Create a table listing all the characteristics of the organisms Hair Bipedal Tail Foot flexibility Written Language Human Ape Mouse Monkey

Step 2: put an X in the boxes that have the trait (for each organism) Hair Bipedal Tail Foot Flexibility Written Language Human X Ape Mouse Monkey

Step 3: count up the Xs. The more Xs the older the trait. Hair Bipedal Tail Foot Flexibility Written Language Human X Ape Mouse Monkey Total 4 3 2 1

Step 4: Draw a diagonal line to represent time Step 4: Draw a diagonal line to represent time. Each point will represent a common ancestor. Each branch is a new species. Traits are written on the main line. Mouse hair

Step 5: Continue until the cladogram is complete Ape Human Monkey Written language Mouse Tail bipedal hair

You try… Characteristic Sponge Jellyfish Flatworm Earthworm Cells with flagella X Body Symmetry Bilateral Symmetry Segmented body