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 Chapter1. 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 discusshow 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 ideaSo 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 (1769-1832)

– 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 (1797-1875)

• 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 -1798– Humans could reproduce faster than

economy could support

Darwin’s Influences

• Extinction

• Gradual Change

• Old Earth

• Adaptation to Environment

• Competition for Resources