Happy Wednesday! Bellwork (Left side): Explain what is happening in this PEDIGREE comparing long-necked giraffes vs short-necked giraffes. Have your homework out and ready to be checked! (color coded bone worksheet)

Terms you should know by now Evolution Gene Pool Natural Selection Mutation Recombinant DNA Non-Random Mating Gen Flow Emigration Immigration Small Population Bottle neck effect Founder Effect

Journals…continued from yesterday Page:_____ Title: Evidence for Evolution EQ: What evidence is there for evolution and how is it used to support the theory?

Biologists use evidence from three major areas to support the theory of evolution. Before we move on you must understand that…. The main goal of each of these is to point to relationships and a common ancestor.

Evidence of Evolution Fossil Record Developmental Molecular Anatomical Homologies Biogeography

Biogeography Study of the geographical distribution of plants and animals *Related Species tend to be geographically close to one another (Ex. Galapagos) *Plate tectonics/continental drift

Evidence of Evolution Fossil Record Developmental Molecular Anatomical Homologies Biogeography

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-14 dating can help determine age *transitional fossils can show evolutionary changes *incomplete

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?

Types of Fossils

How Fossils form

Evidence of Evolution Fossil Record Developmental Molecular Anatomical Homologies Biogeography

The word Homologies refers to similarities among organisms (remember…homo = same) There are three types of homologies that provide strong evidence for evolution and common ancestry

Evidence of Evolution Fossil Record Developmental Molecular Anatomical Homologies Biogeography

Molecular Homologies Similarities in DNA sequences among different organisms Because organisms evolved from a common ancestor, we find similarities in the DNA sequence of all living organisms. The more of a DNA match we see, the closer of a relationship the organisms have.

Evidence of Evolution Fossil Record Developmental Molecular Anatomical Homologies Biogeography

Examine these pictures closely. What do you notice?

Developmental Homologies Different organisms develop from similar starting forms (embryos)

Evidence of Evolution Fossil Record Developmental Molecular Anatomical Homologies Biogeography

Anatomical Homologies Bones and muscles of different species that have similar structures but perform different functions

Scenarios

You will work with your table partner to identify what mechanism the following scenarios describe. You will be using the white boards at your table.

1. The DNA sequence in a bird is changed from ATT CCG TTG to TTA CCG TTG which changes the beak shape from long and thin to short and fat.

2. Northern elephant seals were hunted almost to extinction by people in the 1890s. The remaining population has reduced genetic variation.

3. A lioness joins a new pride and has cubs with the male lion.

4. A small group of birds flies from the mainland to an island and starts a new colony. (The birds never return to the mainland.)

6. Amish people are required by their religion to only marry and have children with other Amish people.

7. Peppered moths are eaten by birds 7. Peppered moths are eaten by birds. The moth color varies from light to dark. Light colored moths can blend in with a nearby species of tree. In the 1800s factories released large amounts of soot, which changed the tree color, so the birds were able to more easily find the lighter moths instead of the darker moths.

8. In 2012, the Yalta Zoo in the Ukraine took ownership of 5 white lion cubs. White lions are caused by a reduced pigmentation (skin color). A very rare occurrence.

9. American bison were once very prevalent in North America, but were hunted close to extinction in the late 1800's. Though the population is recovering, the rapid decrease in population size has led to a population with very little genetic variability