Evolution Notes 03/08/2012

Descent with Modification: A Darwinian View of Life

The Theory of Evolution I will not tell you what you have to believe! –I respect your individual beliefs and opinions I want to do is give you the tools to help you think critically about the facts presented –Always the goal of science!

Goals for the Chapter 1.Learn about the Theory of Evolution and evidence that is used to support this theory 2.Understand the development of this theory in the context of a historical timeline 3.Develop critical thinking skills that help us examine evidence for ALL theories.

Two Requests: Keep an open mind about the content that is presented If you have questions: ASK THEM!

Things we think of when we think of Evolution…….. Adam & Eve Apes Cavemen Jurassic Park dinosaurs planets big bang theory mammoth ice age lies opposing theories Creationism debates difficult to prove monkey-man theory goes against many religions intelligent design

Questions We Have……… What was first? How did the theory start? How long ago was the theory brought up? How long have people been researching it? Is there more than one founder of evolution? Where did the ideas for evolution come from? What are some of the things that point toward each theory? Why is this the theory of how we became who we are?

Questions We Have……… How many animals have evolved? What would we evolve into a million years from now? Who are some of the scientists who worked on them? How long will it be until we’re done evolving for good? Is there any other type of human we don’t know about? Have there been any recent signs that humans are evolving further?

Questions We Have……… Is there other life? Are we really just lucky to be here? What are the odds? If we were a little closer or a little farther from the sun then we wouldn’t survive? When did reptile things evolve? When & how did reptiles become apes? What other scientists helped with this theory?

Questions We Have……… What are the other theories? Did we evolve from monkeys? If we came from monkeys where did they come from? Why haven’t all apes evolved? Who made the discovery of apes & humans being so much alike?

Does evolution suggest that humans descend from monkeys? NO! this is not what the theory of evolution suggests !

Scientific Theory Theory – A set of related hypotheses that have been tested and confirmed many times by many scientists. They allow us to explain and predict.

Evolution as a Theory A theory is a set of related principles based on observations that are in turn used to explain additional observations. They allow us to explain and predict. A good theory is: –Accurate –Coherent –Flexible –Explanatory

Definition of Evolution Evolve – to develop gradually. Evolution- a process of gradual, progressive change Theory of evolution discuss how species change over time

Historical Context for Evolutionary Theory The idea that life evolves was first proposed by Lucretius 2,000 years before the modern theory of evolution So why was such an old idea So controversial?

Science Before Darwin Most people believed that each species was a divine creation that exists, unchanging, as it was originally created. Natural Theology Carolus Linnaeus –Father of “Taxonomy” “Scale of Nature” –Species are permanent, and do not evolve

Historical Context for Evolutionary Theory

Figure 22.2 Fossils of trilobites, animals that lived in the seas hundreds of millions of years ago

Figure 22.4 Strata of sedimentary rock at the Grand Canyon

Historical Context cont…. Georges Cuvier ( ) –Paleontologist Catastrophism - vast geological changes in the earth's history were caused by catastrophes rather than gradual evolutionary processes. –Extinctions –Fossil Record

Historical Context cont…. Uniformitarianism –Charles Lyell ( ) that processes that operated past are not different from those observed now. Slow changes over long periods of time add up to substantial change. Old Earth

Figure 22.4 Strata of sedimentary rock at the Grand Canyon

Lamarckian Evolution First testable theory of Evolution (1809) Use & Disuse –Blacksmith Inheritance of Acquired Characteristics –Giraffe

Lamarckian Evolution First testable theory of Evolution (1809) Change in species is linked to an organism’s environment.

Figure 22.1 The historical context of Darwin’s life and ideas

Historical Context cont…. Thomas Malthus –British Economist Competition for Resources –Humans could reproduce faster than economy could support

Darwin’s Influences Extinction Gradual Change Old Earth Adaptation to Environment Competition for Resources