Penn and Teller video
 https://www.youtube.com/watch?v=_ZF8Y
KjlFtU
 Penn
and Teller on Creationism
Creationism and “Intelligent
Design”

The idea of evolution has been harshly criticized
by religious fundamentalists since the
publication of the Origin in 1859.

This has been especially true in the U.S.

Repeatedly, believers in the literal truth of the
Bible have attempted to have alternatives to
evolution (i.e., creationism) taught in the public
schools and to have the teaching of evolution
either banned or restricted.
Criticisms of Evolution
 Evolution
is “just” a theory.
 Evolution is an “entirely random” process.
 Evolution “promotes selfishness and
cruelty”
Evolution is “just” a theory
 All
scientific theories are backed by
multiple lines of evidence


A theory is not just a “hunch.”
All theories provide broad, overarching
explanations for major aspects of the natural
world and have been extensively tested over
time.
Evolution is “just” a theory
 Other



scientific theories
Gravity
Plate tectonics
Germ theory
 Evolutionary
theory is overwhelmingly
accepted by scientists
Evolution is “entirely random”
 Evolution
includes random and non-random
components



Mutations occur randomly.
However, natural selection is completely
non-random
Natural Selection results in the spread of
mutations that increase the survival and
reproduction of the organisms that possess
them.
Evolution is “entirely random”
 Convergent
evolution also demonstrates
that evolution is non-random


Similar body forms have evolved in distantly
related groups in response to the same
selection pressures.
For example, bony fish, sharks, dolphins and
penguins all show similar adaptations to
swimming efficiently in water: streamlining
and fins.
Evolution “promotes selfishness
and cruelty”
 Natural
selection favors traits that increase
reproductive success



Different conditions select for different traits
Cooperative traits are beneficial under many
conditions.
Cruelty is a human concept Nature is not
cruel. Rather Nature is pitilessly indifferent.
Creationism and “Intelligent
Design”
 The
U.S. Supreme Court has prohibited
the teaching of creationism in public
schools because it violates the
“establishment of religion” clause of the
Constitution.
 Latest
attempt to insert creationism into
schools is the idea of “Intelligent Design.”
Establishment clause
 Establishment
clause is part of the first
amendment to the U.S. Constitution
 “Congress
shall make no law respecting
an establishment of religion, or prohibiting
the free exercise thereof;”
Creationism and “Intelligent
Design”

The concept of “intelligent design” is outlined
most clearly in Michael Behe’s book “Darwin’s
Black Box.”

The central idea in “intelligent design” is that
some structures in the body are so complex that
they could not possibly have evolved by a
gradual process of natural selection. These
structures are said to “irreducibly complex.”
Creationism and “Intelligent
Design”
 By
“irreducibly complex” Behe means that
a complex structure cannot be broken
down into components that are
themselves functional and that the
structure must have come into existence in
its complete form.
Creationism and “Intelligent
Design”
 If
structures are “irreducibly complex”
Behe claims that they cannot have
evolved. Thus, their existence implies
they must have been created by a
designer (i.e. God, although the designer
is not explicitly referred to as such).
Creationism and “Intelligent
Design”
 Behe’s
main examples are various
biochemical pathways in the body, the
blood clotting system, and structures such
as the bacterial flagellum.
Creationism and “Intelligent
Design”
 Since
the publication of Behe’s book, it
has been demonstrated repeatedly that
things he has claimed to be irreducibly
complex are not in fact so.
 E.g.
the flagellum in eel sperm lacks
several of the components found in other
flagella, yet the flagellum functions well.
Creationism and “Intelligent
Design”
 The
blood clotting system in dolphins lacks
at least one component that the human
system has, yet it too is functional.
 In
addition, plausible gradual scenarios for
the evolution of biochemical pathways
including the Kreb’s cycle have been
documented.
Evolution of complex structures
 The
evolution of complex structures, such
as the eye, appears difficult, but natural
selection achieves this by the slow
accumulation of minor improvements from
one generation to the next.
Evolution of complex structures

Each step on the evolutionary pathway from a
simple light sensing cell to a complex eye
capable of focusing and producing color vision,
must be beneficial to the organism that possess
it and a slight improvement on earlier versions.

It is not necessary for a structure to be perfect or
even very good it just needs to be better than
the alternatives to be favored by selection.
Variation in mollusc eyes from (a) pigment spot to (b) pigment cup to
(c) simple optic cup in abalone to (d) complex lensed eyes in a marine snail and
octopus.
Evolution of complex structures
 Computer
simulations suggest that eyes
can evolve easily and in nature eyes have
evolved independently more than 40
times.