Download Giants of Evolution - York College of Pennsylvania

The Evolution of Animals
A Brief History of Evolutionary
Thinking
Figure 01.07b
http://www.flyingsnake.org
Early Viewpoints about Diversity
The prevailing view for most of history in the "educated
civilized world" was that all species were created, perfect,
& immutable.
What is immutable?
The concept is traceable to the Greek philosopher
Aristotle & has been kept alive by judeo-christian
teachings.
Two 18th century, church doctrines (that are alive & well today!!)
1) Separate Creation - all creatures have been created
independently of one another by God and organized into a
hierarchy ("chain of being") with Man occupying the most
elevated rank beneath God.
2) 6,000 year limit on the age of the planet.
But … “things” were being found …
…disturbing things.
Fossils from the Burgess Shale
Fossils were difficult to dismiss
Thinkers began doubting
separate creation & immutability
So … who discovered “evolution”?
NOT DARWIN!!
Not any one person
France was a hotspot of research and thought
about animals and their diversity:
Buffon
Lamarck
Cuvier
English scientists were also important:
Malthus
Lyell
Wallace
Darwin
Georges-Louis Leclerc, Comte de Buffon
(1707-1788)
100 years before Darwin, Buffon, in his Historie
Naturelle, a 44 volume encyclopedia describing
everything known about the natural world, wrestled
with the similarities of humans and apes and even
talked about common ancestry of Man and apes.
Although Buffon believed in organic change, he did not
provide a coherent mechanism …
Buffon also published Les Epoques de la Nature (1788)
where he openly suggested that the planet was much
older than the 6,000 years proclaimed by the church.
http://www.ucmp.berkeley.edu/history/buffon2.html
Jean-Baptiste Lamarck (1744-1829)
"Do we not therefore perceive that by the action of the
laws of organization . . . nature has in favorable times,
places, and climates multiplied her first germs of
animality, given place to developments of their
organizations, . . . and increased and diversified their
organs? Then. . . aided by much time and by a slow
but constant diversity of circumstances, she has
gradually brought about in this respect the state of
things which we now observe. How grand is this
consideration, and especially how remote is it from all
that is generally thought on this subject!"
Text of a lecture given by Lamarck at the Musée National d'Histoire
Naturelle, Paris, May 1803
Lamarck proposed an evolutionary mechanism:
“Inheritance of Acquired Characteristics”
Lamarck’s First Law: use or disuse causes
structures to enlarge or shrink.
Lamarck's "Second Law" stated that all such
changes were heritable.
Results of Laws 1 & 2 -- continuous, gradual
change of all organisms, as they became adapted
to their environments.
Lamarcks’s theory is called transformational
Darwin’s theory is called variational
What does this mean?
Side-Note
Grandfather Erasmus Darwin also proposed a use/disuse
model of evolutionary change.
Erasmus Darwin and Lamarck overlapped in time, but did
not know of each others thinking.
MYTH
Darwin Discovered
Evolution
Darwin’s Contribution:
EVOLUTION …by …
NATURAL SELECTION
CLASS: Take 5 min & summarize Darwin’s concept of
Evolution by Natural Selection
KEY TO DARWIN’S THINKING …
Thomas Malthus (1766-1834)
"In October 1838, that is, fifteen months after I had begun my systematic
inquiry, I happened to read for amusement Malthus on Population, and
being well prepared to appreciate the struggle for existence which
everywhere goes on from long- continued observation of the habits of
animals and plants, it at once struck me that under these circumstances
favourable variations would tend to be preserved, and unfavourable ones
to be destroyed. The results of this would be the formation of a new
species. Here, then I had at last got a theory by which to work".
Charles Darwin, from his autobiography (1876)
Malthus – political economist
“Essay on the Principle of Population” produced
The Malthusian Doctrine
Malthus focused on 2 unquenchable “hungers”:
* Needing/Wanting Food
Humans can’t control either !!
* Needing/Wanting sex
Essence of Malthus:
Population increases geometrically while the means of
subsistence increases arithmetically.
Geometric Increase of People
dN = rN
dt
N = population size
r = rate of increase (= births – deaths)
Nt = Noert
No = beginning pop size
Arithmetic Increase of Food
dF = k
dt
Ft = Fo + kt
geometric
increase
arithmetic
increase
Malthus
In the world of Malthus, human population size
seemed stable … How? Why?
War, famine, and disease provide the checks on
population growth.
QUESTION: In 2010, is
Malthus still valid?
The Path of Charles Darwin
Career attempt 1: Med School
Career attempt 2: The Ministry
Career attempt 3: Naturalist (scientist)
Age 22: Set sail on the Beagle … returned 5 years later
with radical ideas.
Great Book: The Voyage of the Beagle
Darwin Characteristics
Ultra-cautious
Deliberate
Thorough
Systematic
Sickly
Fearful of public & church reaction
This book rocked the world
in 1859 … most Western “civilized
countries” have come to terms with it.
One country has not ….
The USA … Why??
The book did 2 things:
** It convinced many people that evolution has happened.
A massive book of evidence that crushed the concept of
immutability.
Instead … SLOW CHANGE!
** It proposed a mechanism.
A cottage industry of Darwin caricature began
with the publication of Origin.
Figure 06.14
Evolution by Natural Selection … Know This!!
“I hardly know whether I at first felt more vexed at the
solution not having occurred to me, than pleased that
it had been found at all … “
Alfred Newton
“How extremely stupid not to have thought of that”.
T.H. Huxley
“I coulda dunnit easy … piece a cake!”
B. Rehnberg
All Animals Have Excessive Reproductive Capacity
750 years
2 elephants
19,000,000 elephants
5 months
191 x 1018 houseflies
2 houseflies
48 hours
1 bacterium
bacteria cover the earth
to a depth of 7 feet
2 humans??
FROM MALTHUS!
Anatomical
Variability
FROM OBSERVATIONS
ON THE BEAGLE
Physiological Variability
Biochemical Variability
Behavioral Variability
Immunological Variability
etc.
etc.
Survival Advantage??
How many have heard of Alfred Wallace?
Wallace was 14 years younger than Darwin.
Grew up relatively poor and could not go to college.
While working as a surveyor, he began to develop an
interest in natural history.
Few jobs in England ….. few career options … he
became a collector.
He launched two large-scale collecting
expeditions:
1) Amazon River basin -- set sail at age 25!
2) South Pacific (Malay Archipelago).
Animal diversity shocked him! Started thinking.
Caught malaria … high fever … hallucinations … his
thoughts turned to Malthus!! Light bulb!!
Concept of natural selection popped into his head.
1 week later, a manuscript was on a ship to England.
Who did Wallace send it to???
To Darwin!!!
Imagine the horror of June 18, 1858 when Darwin opened that
letter.
10 days later, Darwin’s baby boy, Charles, died of scarlet fever.
He was a crushed man.
Darwin gave Wallace’s letter and ms to Charles Lyell … the
rest is happy history.
Joint Wallace/Darwin paper was read in 1858.
Darwin waited almost 20 years to publish his ideas - why??
Darwin Characteristics
Ultra-cautious
Deliberate
Thorough
Systematic
Sickly
Fearful of public & church reaction
Fast forward 146 years
Kent, England
York County, Pennsylvania
Dover school board rejects a popular high
school biology text because it is …
“laced with Darwinism”
The Evolution of an Idea
Creationism
Scientific Creationism
Intelligent Design
“Fair and Balanced” Treatment in Public Schools
??
http://www.alaska.net/~clund/e_djublonskopf/Flatearthsociety.htm
(Dover, PA)
What is it about the United States?
No other “advanced” country is going
through evolution agony.
Why us?
New Pub:
Answers Research Journal
… a free online journal devoted to
research on “recent Creation and the
global Flood within a biblical framework”.
Papers will be peer-reviewed by those
who “support the positions taken by the
journal.” (!!!)
http://www.answersingenesis.org/arj
The End