Development of Evolutionary Theory

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Exploring Biological Anthropology:
The Essentials, 3rd Edition

CRAIG STANFORD

JOHN S. ALLEN

SUSAN C. ANTÓN

As you work through this set of chapter slides, keep in mind the notations that are included from your instructor. Open, read carefully, download if necessary, and use in conjunction with your reading and video lesson study. All these components supplement each other. The wise student will keep this in mind.

Chapter 1
Origins of Evolutionary Thought

Even the “Evolutionary Thought” process had a beginning. Carry on!

What is Science?

Standard scientific research procedure in which a

hypothesis is stated, data are collected to test it,

and the hypothesis is either supported or refused

The Scientific Method

Remember this:

Scientific reasoning is a process, NOT a result.

Does NOT have all the answers; should not be “reified”

Seeks to answer “enigmatic” questions: e.g., What is matter?

Science is “SELF CORRECTING”; we constantly refocus the lens as new data emerge.

The Scientific Method

Observation

experimentation

deduction

hypothesis

THE MANY facets OF SCIENCE:

Science is the activity/process of seeking out RELIABLE Explanations (can be verified) for OBSERVABLE phenomena

Cannot address issues of the supernatural.

(ii) Science, a search for order (theory is result of process):

* Question: “Why bipedalism”?

* Hypothesis: make an educated guess

* Test the hypothesis (observe/collect data/identify variables (consistency & variation). Clarify the hypothesis; is it falsifiable?

* Organize a thesis, support w/evidence, publish it.

* After repeated testing, a theory emerges.

* N.B. SCIENCE IS SELF CORRECTING

SCIENCE, A CREATIVE PROCESS:

Follow hunches, ask questions, and think creatively. E.g. The geaky kid in us when we want to know how the fruit fly embryo develops its various body

parts; the answer, of course, lies with the “switched on” genes.

C. APPLICATION OF SCIENTIFIC THINKING to Anthropological Problems:

Monocausality: Water to ice! Relatively direct, transparent. As opposed to Multicausality: Why primates behave as they do; genes + environment

SCIENCE & RELIGION:

* Credibility in science is based on facts, data, empirical observation

* Credibility in religion--Faith! Different starting points.

Question: Why does my child have eight limbs?

Religious Answer: perhaps she is a reincarnation of the Hindu goddess Lakshmi

Medical Answer: confused development at genetic level

* The scientific method has been consciously & cooperatively employed for approximately 200 years now. Arose very much so in Monasteries/religious centers. Read about Mendel in this and other chapters. This background is the reason that Latin is the language of medicine & science.

Conclusion: THEORY in science is NOT mere “opinion” and cannot be based on faith or “I believe it because someone says it’s so.”

The Early Thinkers

The Roots of Modern Science

Ancient Greeks

often are credited with the first written efforts to understand the natural world and our place in it

Aristotle

First known animal and plant classification

Immutability of species

First, think of the following:

* Legacy from Medieval thinking and tripartite cosmology (heaven/earth/hell); this was taken literally. Even today we have the “flat earth society”!

* Three world views based on Medieval thinking include: Anthropocentricity; spontaneous generation; immutability. Look up their definitions!

* Greeks very aware of fossils/dinosaurs, etc., but they viewed these in light of the mega figures from their creation stories & their mythology.

* Next, consider Aristotle’s “great chain of being” idea—-the “ladder of life” leads to man; a static view of reality.

The Roots of Modern Science (cont’d)

The Renaissance (14th – 16th centuries)

“Rediscovering” the Greeks and Romans
Sense of time
Sense of cultural variation

* In 13th through 15th centuries we see a burst of learning/creativity: Renaissance thinkers rediscover Greek + Roman ideas. Also, a new awareness of great variety of life forms contrasts with the older ideas and the static view of reality.

Until Polish mathematician Copernicus challenged the view that the earth was at the center of our universe (1514), that view had held sway for about 1500 years, or from the time of Aristotle.

The Roots of Modern Science (cont’d)

The study of human anatomy

Global exploration

European Naturalism

* Age of Discovery/circumnavigation of globe; “other” people & other life forms exist; Yikes! Christy Columbus gets lost on his way to India!

* 16th Century: Copernicus (1473-1543: issue of Heliocentric universe (Helios in Greek = Sun) clashed with accepted thinking of an earth-centered universe.

17th Century: John Ray (1627-1705 introduces binomial system of classification for life forms; genus & species.

THINGS WERE GOING NICELY UNTIL SOMEONE WANTS TO “DATE” EARTH!

* Enter James Ussher (1581-1656) and his biblical generations. Earth created by God on December 23, 2004 B.C. Until Ussher “evolution” was not a hot button issue in Western religion.

* 18th Century: Carolus Linnaeus (1707-1778 Sweden): Systema Naturae (systems of nature) published in 1735 standardized & developed Ray’s otherwise sporadic use of the binomial nomenclature

Linnaeus and the Natural Scheme of Life

taxonomy

Binomial

nomenclature

Know this very important concept.

The Road to the
Darwinian Revolution

Comte de Buffon (1707 – 1788)
Accepted the notion of biological change
Georges Cuvier (1769 – 1832)
Catastrophism
Geoffroy Saint-Hilaire (1772 – 1844)
Opposed Cuvier
Jean-Baptiste Lamarck (1744 – 1829)
Theory of the inheritance of acquired characteristics

A little more on this:

a. The cast of 18th century characters:

* Comte de BUFFON 1707-88 (aka Georges-Louis LECLERC) a forerunner to Darwin. New environments lead to new forms.

* Erasmus Darwin (1731-1802); grandfather of Charles, published Zoonomia, his poetry, in which he says, “life began beneath the waves...” Garden of Eden model is now questioned.

b. The 19th Century:

* Cuvier (1769-1832) the anti-evolutionist and his idea of Catastrophism---disasters like “the flood” are followed by new waves of divinely created life forms, thus the various layers of fossils. Polygenism, alternative to Monogenism.

* Geoffrey Saint-Hilaire (1772-1844): Anatomist & a very clear thinker debated Cuvier on the nature of fossils; proponent of evolution

* Lamarck (1774-1829; into early 19th c.)--He is important because he was the first to articulate a systematic theory of evolution. Lamarck’s “theory of acquired characteristics” suggests the “Baby Arnold” scenario! That is…any Schartzenager boy offspring will inherit A’s pecks and will be a mini Arnold!

Positive overall contribution from Lamarck---environment acts on organisms

Problem—evolution does not come about in single generation.

The Uniformitarians:
Hutton and Lyell

Theory that the same gradual geological process we observe today was operating in the past

James Hutton (1726 – 1797)

Charles Lyell (1797 – 1875)

* James Hutton (1726-1797) and Uniformitarianism: science of stratigraphy reveals the geological processes (earthquakes, volcanoes, weather, etc.) that shape the earth. Look at today, learn how it happened yesterday. Even still, he was influenced by theological thinking of his day. God was the “first mover & shaker.”

* Charles Lyell (1797-1875): synthesized the new data in Principles of Geology (1830)

* William Smith (1769-1839): first geological maps of English countryside; fossils. No Darwin and the “Beagle” just yet.

Big issue now….Humans Before “Adam” and “Eve”? More 19th c. developments here include:

Jacques Boucher de Crevecoeur de Perthes (1788-1868); systematic archeological excavations in south of France; unearthed evidence of prehistoric man; did not dare publish for 20 years or so! Afraid of religious censure.

The Darwinian Revolution

Charles Darwin (1809 – 1882)
Voyage on the HMS Beagle
1831-1836
Southern Hemisphere
The Galapagos
Variations of tortoise
Finch variation
Adaptive radiation
Biogeography
Natural Selection

By the time of Darwin (1809-1882), the medieval cosmology supporting the ideas of “anthropocentrism”, “spontaneous generation”, “immutability” & the 4004 B.C. birth date for earth were passe.

a. Charles Darwin: Voyage of 12/27/1831 (see Fig. 2.11) [Q.1-2]

Darwinian’s big contributions: “Natural Selection” & The Voyage of the Beagle

b. Oops! Alfred Russel Wallace (1823-1913)

(Box 2.1 Darwin vs Wallace?)

(Box 2.2 What Is Intelligent Design?)

Charles Darwin pictured five years prior to the publication of On the Origin of Species.

Refining the Theory of Evolution by Natural Selection

Observation 1: All organisms have the potential for explosive population growth
Observation 2: Yet populations are roughly stable…
Deduction 1: There must be a struggle for existence
Observation 3: Nature is full of variation
Deduction 2: Some variations are favored while others are not

Read over these important concepts and think hard on them.

Natural Selection

The trait in question must be inherited
The trait is question must show variation between individuals
The environment must exert some pressure on the trait

Fitness

Population

Mutation

More important issues here!

Common Cactus Finch. Recall Darwin’s study of the Galapagos Finches.”

Science and Creationism

Faith vs. Testable Evidence

Supreme Court Rulings

“Creation Science”

“Intelligent Design”

Captain Fitzroy (captain of the Beagle) and Professor Owens’ (renowned naturalist who assisted Darwin) reactions when Darwin suggests that he must do further more systematic study on the Galapagos finches & their differences. **** Why bother? God did it! ****

Lyell’s influence on Darwin stemmed from the science of geology & idea of uniformitarianism. (also influential were Hutton & Smith, geologists)

* The BUTLER ACT 1925 TN legislature prohibited teaching of theory of evolution in schools & universities supported by public money. Repealed in 1967.

* The Scopes Monkey Trial. Bryant vs Darrow (read chapter on this)

* THE COURTS OF LAW on teaching creation science ideas and/or theory of evolution in public schools: June 19, 1987 Supreme Court ruling 7/2 strikes down Louisiana “Balanced Treatment Act” as being unconstitutional. BUT in 1999 Kansas State School removes topic of evolution from state competency tests!

* Creation-Science Approach: the bible “can refute” science

* INTELLIGENT DESIGN: irreducible complexity of life (see textbook on this)

* Evolution theory after Darwin--The synthetic theory (see textbook)

* Mendel’s principles of heredity you (must read up on this)

Breed: Tall w/tall; Short w/short; Violet w/violet; Smooth seed w/smooth seed; “Colored” seed w/colored seed, and so on. Focused on seven traits to discover the principles of heredity.

In 1925, a football coach and part-time biology teacher named John Scopes was arrested for teaching evolution in defiance of Tennessee state law. For eight sweltering days, hundreds of people streamed into the little town of Dayton, TN to watch his trial. It became an epic event of the 20th century, a debate over free speech that spiraled into an all-out duel between science and religion. It featured two of the greatest orators/speakers, attorneys Clarence Darrow and W. Jennings Bryan. The Scopes trial was the first major media event of modern times, and hundreds of reporters and live radio coverage spread the sensational news.

Outside the courthouse, a circus-like atmosphere went on as a chimpanzee in a suit competed with the fire-and-brimstone preachers for the crowd’s attention. This sensational event brought to light and heightened a great cultural divide in the United States that continues to this day. That is the opposing forces of Fundamentalist Christianity and the scientific community. The slogans outside the courthouse and around the little town of Dayton displayed the fear that science, and particularly the theory of evolution would undermine religion. Worst of all, the theory of evolution meant that humans were derived from monkeys. (11/8/04 Georgia law & textbooks)

The Scopes Trial would inspire the 1960 Stanley Kramer movie named “Inherit the Wind.” In the 1970s TV show “Roots” sparked great interest in Africa, as well as interest in both human and animal ancestors.

Question: What makes us unique among the primates?

The answer lies deep within our chromosomes. There will be more on this down the line, but for now check out “Karyotype” (p.48) and keep in mind the following “scores” (not basket ball): Apes 24 // Homo 23