The origin and design of life

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The origin and design of life
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Outline

• Evolutionary theory
• What are organisms?
• Natural Selection vs. Intelligent Design

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Logic of Darwins argument

• Natural populations could grow exponentially

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Exponential growth
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Logic of Darwins argument

• Despite this potential for exponential growth,
  natural populations normally are relatively
  stable
  
• Many individuals do not leave as many offspring
  as they might
  
• Those best suited to the prevailing environment
  will leave the most offspring (i.e. the best
  fit to the environment

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Logic of Darwins argument

• Because of heredity, offspring are like their
  parents
  
• Over many generations, natural selection builds
  individuals that are progressively better adapted
  to their environment

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Natural Selection

• 3 essential components
• Variation
• Inheritance
• Selection
• Differential reproductive success
• Over time, natural selection produces designs for
  reproduction (adaptations)
  

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The easy way

• Imagine a gene that happens to make an organism
  more likely to be X.
  
• Would that gene become more common in the next
  generation?
  
• If yes, it will be selected for and we should
  look for it in nature.
  
• If no, it will disappear and shouldnt be found
  in nature.

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Two general approaches

• Phylogenetic approach organisms are related to
  each other by virtue of common descent
  
• Searches for features that are similar because
  both species inherited them from a common
  ancestor
  
• Adaptationist approach organisms have particular
  design features by virtue of their unique
  evolutionary histories
  
• Explores how natural selection functionally
  organizes the design of organisms can be applied
  to unique features

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Phylogenetic approachWho are you?

• Kingdom Animalia
• Phylum Chordata
• Subphylum Vertebrata
• Class Mammalia
• Order Primate
• Family Hominidae (includes Homo erectus)
• Genus Homo
• Species Sapiens
• Subspecies sapiens (not neanderthalenis)

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An evolutionary tree of primates based on DNA
evidence
after Goldsmith Zimmerman (2001)
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Adaptation Products of Evolution

• Organisms are composed of the following three
  features
  
• Adaptations (design features)
• Solve particular adaptive problems (i.e.
  selection pressures)
  
• By-products
• Noise
• Can apply this classification to features of
  man-made artifacts as well

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Adaptations (design features)

• Inherited and reliably developing characteristics
  that come into existence through natural
  selection because they helped to solve problems
  of reproduction during the period of their
  evolution (i.e., in the EEA)
• EEA Environment of Evolutionary Adaptedness
• E.g., umbilical cord

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Adaptive problem

• Anything that affects reproduction
• E.g., finding food, avoiding predators, fighting
  disease, competing or cooperating with
  conspecifics, finding a mate, giving birth,
  raising an offspring
• Had to recur across many generations
• Its solution had to affect reproduction, however
  indirectly

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Features of adaptations

• Reliably developing
• Specialized
• Show evidence of design
• Adapted to ancestral environments

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By-products

• Characteristics that do not solve adaptive
  problems and do not have functional design they
  are carried along with characteristics that do
  have functional design because they happen to be
  coupled with those adaptations
• E.g., belly button

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Noise

• Random effects produced by forces such as chance
  mutations, sudden and unprecedented changes in
  the environment, or chance effects during
  development
• E.g., particular shape of a persons belly button

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Life Machinery

• Natural selection provides a causal explanation
  of design
  
• The organism is a self-reproducing machine.

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Structure reflects function

• Organisms are highly ordered entities
• Organization comes from natural selection
• Chance processes act to randomize relationships
  within organism
  
• Superhero problem
• Bunny in the blender
• Natural selection is NOT chance

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• Natural selection is a feedback process
• Design modifications that improve reproduction
  spread throughout the population

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Biological functionality is weird

• In evolutionary theory, to say a feature was
  adaptive means that, in the environment in which
  that feature evolved, that feature promoted its
  own reproduction
• Adaptive does NOT mean
• Beneficial in terms of well-being, health,
  happiness or other human values
  
• Good for the species, group, or even individual
• The feature is desirable or inevitable
• Nature is indifferent, not cruel or benevolent

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Test yourself

• How do fruits and vegetables reproduce?
• Fruit Vegetables
• Edible?
• Cook?
• Sugar?
• Toxins?
• Colors?
• Defenses?

Almost all A few None Most High Very low
Low High Bright Camouflaged Pesticide Pesti
cide, poison, thorns, bark
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Natural Selection, Intelligent Design
Creationism
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Caveat Why bother?

• Reasons not to teach ID or Creationism
• Can be offensive to the religious
• You hear enough bashing of conservatism
• Theres no real debate we dont teach
  astrology, e.g.
  
• Reasons to teach the controversy
• Expose the lack of actual controversy
• Brings to light evidence you wouldnt otherwise
  see
  
• Educate those who dont know the main arguments
• They asked for it

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Data in support of Natural Selection

• comparative morphology (e.g. hands on whales)
• fossil record of transitional forms
• Carbon, Potassium-Argon dating of those forms
• mDNA clocks dating of those forms
• geological evidence supporting timing of those
  forms
  
• comparative embryology
• all life come from their own kind (unlike all
  tools)
  
• all life shares same biochemical background
• vestigial organs (e.g. man-nipples fingernails)
• NO species designed for non-reciprocal aid of
  another
  
• design flaws (e.g. backward retina)

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Flawed Design examples in humans
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Data in support of Natural Selection

• 50/50 sex ratio
• Inter-species conflict
• Intra-species conflict
• Intra-genomic conflict
• visible mutations
• visible inheritance

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Data in support of Natural Selection

• mathematical certainty of natural selection given
  mutations and inheritance
  
• behavioral patterns in hundreds of species
  indicating design for reproduction
  
• blurred lines between species, e.g. donkey/mule,
  wolf/pug
  
• creation of different species through
  artificial selection, e.g. nuclear bacteria
  
• watching natural selection take place (e.g.
  sickle cell anemia, resistant bacteria, lactose
  tolerance)
  
• Etc.

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Percentages of people with lactose intolerance
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Intelligent Design advocates say

• Irreducible complexity
• By irreducibly complex I mean a single system
  composed of several well-matched, interacting
  parts that contribute to the basic function,
  wherein the removal of any one of the parts
  causes the system to effectively cease
  functioning. Michael Behe
• How could natural selection design this?
• E.g. a mousetrap, a single-cell organism?
• If it requires all functional parts at once,
  natural selection cant design itright?
  
• Therefore, some intelligent being designed it

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Intelligent Design

• Three kinds of ID
• Creationism
• Design of species
• no whale transitional forms
• First causes
• ID happened billions of years ago

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Magic Trick Fallacy

• http//www.youtube.com/watch?vUYTmEVFL_NA
• Intelligent Design works like magicians
• Your theory fails to explain some stuff
• Therefore, my theory is right
• Problem?
• Its not enough that we are wrong, YOU have to be
  right.

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Data in support of Intelligent Design

• None
• ID doesnt make predictions.
• Thesis of ID Someone did something somehow at
  some time that natural selection cant explain.
  
• ID doesnt make predictions
• Creationism does

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Creationism

• Two creationist accounts in Genesis
• Genesis 124. And God said, "Let the land
  produce living creatures according to their
  kinds livestock, creatures that move along the
  ground, and wild animals, each according to its
  kind." And it was so. (125) God made the wild
  animals according to their kinds, the livestock
  according to their kinds, and all the creatures
  that move along the ground according to their
  kinds. And God saw that it was good. (126)Then
  God said, "Let us make man in our image, in our
  likeness, and let them rule over the fish of the
  sea and the birds of the air, over the livestock,
  over all the earth, and over all the creatures
  that move along the ground."

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Creationism

• Genesis 218. And the LORD God said, It is not
  good that man should be alone I will make him a
  helper comparable to him. 219 Out of the ground
  the LORD God formed every beast of the field and
  every bird of the air, and brought them to Adam
  to see what he would call them. And whatever Adam
  called each living creature, that was its name.
  220 So Adam gave names to all cattle, to the
  birds of the air, and to every beast of the
  field. But for Adam there was not found a helper
  comparable to him.
• 221 And the LORD God caused a deep sleep to fall
  on Adam, and he slept and He took one of his
  ribs, and closed up the flesh in its place. 222
  Then the rib which the LORD God had taken from
  man He made into a woman, and He brought her to
  the man.

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Creationist account of animals

• Account 1 suggests that animals should be
  designed for humans to lord over.
  
• Account 2 suggests that animals should be
  designed for male companionship.

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Data contradicting Creationism

• Universe infinitely larger than necessary to
  house humans
  
• Earth not designed for us
• Worst possible shape for surface dwelling
  creature
  
• More water on surface than land
• Much of the land not hospitable
• Earth has existed for billions of years, humans
  for 100,000
  
• Immune system AND diseases?
• Life appears to fight itself, which is
  inconsistent with single creator
  
• Oxygen and breathing?
• Physics structured in ways that introduce
  problems, then massive design to solve it.
  Whoever designed physics didnt do it for humans.

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Data contradicting Creationism

• Animals run away? Resist being eaten? Fight
  back?
  
• If they are helpers or servants they shouldnt do
  that
  
• Genesis 9 changes this, but reaffirms that
  Every creature that is alive shall be yours to
  eat.
  
• Natural plants are high in useless toxins
• Most plants are inedible because of toxins
  manufactured for that purpose
  
• Most animals are highly inedible without great
  preparation
  
• Only fruit seems well designed for consumption
• and then only when the fruit can reproduce
• Animals exist at the bottom of the ocean
• Microscopic life?

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Data contradicting Creationism

• comparative morphology (e.g. hands on whales)
• fossil record of transitional forms
• Carbon, Potassium-Argon dating of those forms
• mDNA clocks dating of those forms
• geological evidence supporting timing of those
  forms
  
• vestigial organs (e.g. man-nipples fingernails)
• design flaws (e.g. backward retina)

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What controversy?

• The data is such that there is no debate between
  evolution and creationism among anthropologists,
  archaeologists, geologists, astrophysicists, or
  any other group of scientists.

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Explaining Irreducible Complexity

• Irreducibility can evolve after addition of new
  features.
  
• Example of an irreducibly complex object

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Explaining Irreducible Complexity

• Bridge
• Add better part
• Remove useless part

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Data contradicting Natural Selection

• None.
• After 150 years of the most vehement attacks any
  scientific theory has ever had there is not a
  single reliable data set contradicting natural
  selection
• This doesnt mean we understand everything.
• E.g. car manufacturing and the laws of physics

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Nonsense about Natural Selection

• An ant is less evolved than a monkey
• It means less human like but thats silly
• Survival of the species
• Animals have instinct which has evolved and
  reason which hasnt
  
• Evolution doesnt apply to humans because we
  learn.
  
• learning is something natural selection
  designed animals to do
  
• other animals learn

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Conclusions

• Natural selection created and designed life on
  earth into self-replicating machines.
  
• Next time
• Evolutionary Psychology how can an understanding
  of natural selection help us understand the
  workings of the human brain?
  

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• Readings for this week
• Buss Ch. 1 2
• No Section on first week
• See me for add codes