Bellwork•Hominids are a group of animals that includes humans and similar upright-walking ancestors.

1. Write a sentence saying how long you think hominids have existed compared to dinosaurs. (be specific!)

Ex. #1 If you think hominids have been around for more time use a multiple, for example: “Hominids have been alive 5 times longer than dinosaurs were alive.”

Ex. #2 If you think hominids have bee around for less time than dinosaurs lived, use a fraction, for example: “Hominids have only been around for 1/3 as long as dinosaurs were alive.”

How does natural selection work on single gene traits?

Leads to changes in allele frequencies and causes evolution

Variations exists

What are the other 3 things

necessary for natrual selection

to occur?

So…just how LONG has life been evolving? Not every change is due to a deadly allele….

Post-itYou will be given a slip with a milestone event in the history of life on Earth.

Without talking to anyone but your partner, place it on the timeline of the Earth’s history.

Lined PaperList any events that sound….out of place

Learn it well enough to teach it.In your group, carefully read and take notes on your section of the Earth’s history.

You will have 8 minutes to prepare a short (2-3 minute) summary for the class that covers the important milestones in your article.

You must be prepared to answer questions about dates and events.

Take notes- 4 different erasListen for important events, especially yours!

History of Life on Earth

1. RePost-ItTake your notes and go adjust the life-event you put up earlier.

2. Write summaries on notetakerIn proper English write a 1 paragraph summary for each era. NOT a list of events. Think about these questions: “What do all of the events in this era have in common? What is important about this era in terms of evolution?”

Closure – underneath summaries on notetaker•Use what you learned today to sketch a timeline of the Earth’s history starting at 4.5bya. •Make the time line to scale.•Accurately place the following events on your timeline:• First evidence of life• Time of the dinosaurs• Emergence of humans

Closure- cont.

This chart is a common representation of geologic time. The Jurassic period, when dinosaurs were a dominant life form, is shown near the center of this scale. [Locate the Jurassic period on the chart at the right.] On your paper, write where the Jurassic period was placed on our class’ time line on the wall, and briefly explain the difference between the two charts. What is at the center of our class time line?