Evolution and Creationism: What Everyone Needs to Know

Evolution and Creationism:What Everyone Needs to Know

1. What is science?2. Evolution: a quick overview

-- evidence -- mechanisms

3. The age of the Earth/”how do you know how old it is?”

4. What is creationism5. Evolution answers questions7. Why is evolution important?

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Science =

-- a “Way of knowing”-- materialistic/naturalistic-- hypotheses that are testable and

provisional

Science

-- certainty-- ethics-- values-- religion-- politics-- the answer for every question-- all of human thought

Organic Evolution

Definitions: The hypothesis that all organisms on Earth are

connected by bonds of genealogy and have changed through time.

Darwin: “descent with modification”

The Origin tried to do 2 things:

• 1) Convince the reader that evolution has occurred and is an adequate explanation for observations about life.

• 2) Convince the reader that a particular mechanism – natural selection – is the main cause of evolution.

The occurrence of evolution (“the fact of evolution”)

… mechanism by which evolution

occurs.

Evolution is scientifically useful.

it is testable

it answers questions

it stimulates further research

“How did organisms come to be the way they are?”

• They have a history.• They don’t. They were created as we see

them.

• We can extrapolate from changes we observe today.

• We cannot extrapolate from changes we observe today.

Evidence for Evolution

• 1) Biogeography

• 2) Fossil record

• 3) Classification

• 4) Comparative Anatomy

• 5) Observed small-scale changes

• 6) Genetics

Some examples…(there are thousands…)

Evidence for Evolution: Biogeography

Evidence for Evolution: Biogeography

Toucan (Neotropics) Hornbill (SE Asia)

Evidence for Evolution: Biogeography

ArchaeopteryxCompsognathus

Archaeopteryx and modern pigeon

Evidence for Evolution: The fossil record

Evidence for Evolution: Comparative Anatomy

North Atlantic Right Whale

No serious practicing geologist or organismal biologist has seriously questioned whether evolution has occurred, or whether it is an adequate explanation for the history and diversity of life since at least the 1890s.

There has been, and continues to be, debate about the causes and mechanisms of evolutionary change.

Mechanisms of Evolution

• Directed evolution/Internal mechanisms - “orthogenesis” etc.

• Inheritance of acquired characteristics (“Lamarckism”)

• Genetic drift• Neutral theory• Natural Selection• Higher level sorting

Natural Selection

Definition: The non-random and differential reproduction of

different genotypes acting to preserve favorable variants and

eliminate less favorable variants.

“3 unarguable observations and 2 inescapable conclusions”

• Observations:– 1) There is variation

– 2) At least some of it is inherited

– 3) There is vast overproduction

• Conclusions:– 1) There is a “struggle for existence”.

– 2) On average, those individual organisms with traits that confer some advantage in this struggle will leave more offspring.

The age of the Earth

• aka: “how do you know how old it is?”

• aka: “aren’t there problems with ‘carbon dating’?”

“How do you know how old it is?”

Techniques for dating things • Relative dating: “X is older than Y”• Numerical dating: “X is Y years old”• Historically unique events: e.g., 1965 Mustang• Processes of change (observe results): e.g., weathering,

deterioration, erosion• Processes of change (experiments): e.g., moldy cheese• Historically repeating events: e.g., Greek revival

architecture

Using fossils to tell time: biostratigraphy

Radiometric Dating: the basic idea

• A product is detectable

• The rate of production of that product is known

• Product amount is 0 (or known) at age 0 of sample

• Product / Rate = Time– example: 10g / 0.5g/yr = 20 years

Seneca Stone Quarry

http://www.earth.rochester.edu/ees207/Eastern_Transect/senecastone.html

Bentonites (ancientvolcanic ash layers)in the Seneca StoneQuarry

http://www.earth.rochester.edu/ees207/Eastern_Transect/senecastone.html

1. What is science?2. Evolution: a quick overview

-- evidence -- mechanisms

3. The age of the Earth/”how do you know how old it is?”

4. What is creationism5. Evolution answers questions7. Why is evolution important?

“Creationism” isn’t science

Creationism: a definition

• General: The Universe, the Earth, and all life were created directly by a supernatural creator (God).

• Variations:– young Earth vs. old Earth– one creation (“special”) vs. many (“sequential”)– non-humans vs. humans

Creationism: a taxonomy

• Scientific creationism (no reliance on Biblical revelation, utilizing only scientific data)

• Biblical creationism (no reliance on scientific data, using only the Bible)

• Scientific Biblical creationism (full reliance on Bible, but also using science)

(from Scott, Evolution vs. Creationism, 2004)

Creationism and science

• It was cutting-edge science… about 500 years ago.

• It has been tested, and it failed.

• Current public opinion, however…

U.S. public opinion, 2005

HALF OF AMERICANS ARE “CREATIONISTS”

• 54% do not think human beings developed from earlier species (up from 46 percent in 1994)

• 49% believe plants and animals have evolved from some other species; 45% do not believe that.

• 46% believe apes and humans have a common ancestry; 47% believe we do not.

• 46% agree that "Darwin’s theory of evolution is proven by fossil discoveries“; 48% disagree.

Source: Harris poll, June 2005

Poll by the Pew Forum on Religion & Public Life,

conducted July 2005 among 2,000 U.S. adults

• Life has existed in its present form since the beginning of time: 42%

• Life has evolved over time: 48%– Guided by a supreme being: 18%– Evolution by natural selection: 26%– Don’t know how evolved: 4%

• Don’t know: 10%

Polls 2001

BUT

• “Evolution should be taught in the public schools” (70%)

• “The continents on which we live have been moving their location for millions of years...”. (79%)

Intelligent Design: what is it?

• Holds that “where there is a watch, there must be a watchmaker”.

• Living things are too complex not to have been designed by an intelligent designer.

• Claims to accept evolution and an old Earth.

Intelligent Design:How to answer a question about it

• Even if it doesn’t mention God, religion, or a “creator”, it assumes there is/was one.

• This is supernatural and non-testable.

• It’s not science.

Why does this matter?

• Science

• Science education