EVOLUTION I. Definitions A. Evolution = Change Through Time 1. Examples a) Surface of earth ~ 6billion years old i. Much evidence to indicate change ii. Acted on by force of nature b) Baseball i. Rules ii. Uniforms c) Social Structure of Society i. Dating age

Evolution d) Dress e) Automobile designs f) DNA i. Random mutations ii. Good ones can be passed on g) Living species i. Many species have ancestors that look very different ie: horses ii. Many species are extinct(prior to man) iii. Many species show signs of change now ie: bacteria exposed to antibiotics

Evolution E. Scientific Theory 1. Hypothesis which has been proven to be correct many, many times F. Popular Theory 1. hypothesis that has been untested G. Belief 1. Idea untested w/I framework of science a) Is not based on science b) May be right or wrong 2. Often based on philosophy

Evolution a) Science cannot be used to prove or disprove philosophical ideas b) Philosophy cannot be used to prove or disprove scientific theories c) Each discipline is valid within it’s own framework III. Evolution according to Lamarck A. Theory of acquired characteristics 1. Individuals change during lifetime 2. According to Lamarck these changes could be passed on a) Giraffe stretching to reach branch

Evolution 3. Ability to run faster 4. Results of weight training 5. Knowledge of biology 6. Lamarck’s ideas were Never Proven 7. Accepted for 50 yrs. as fact

Evolution IV. Darwin A. Son of Doctor B. Well educated C. Excellent naturalist D. Completed Theology Degree E. Set sail on Beagle - World tour 1831 F. Took Charles Lyle’s book on geology 1. Started that shape of the earth was due to

Evolution 2. Small and constant forces and not catastrophes - ie: erosion, wind, water G. Made many observations on the voyage that led to hypothesies H. Returned from voyage with ideas on evolution formed 1. Spent 20 years refining ideas and writing “Origin of Species” 2. Published when Wallace came to same conclusions

Charles Darwin I. Charles before voyage II. Charles late in life

HMS Beagle

Fitzroy

Wedgewood China

Alfred Russell Wallace

Evolution V. Theory of Evolution by Natural Selection (Darwin and Wallace) A. All species have the ability to produce more offspring than can actually survive 1. From any pair only 2 offspring will survive and reproduce in stable population 2. Salmon 3. Grasshoppers B. Supply of resources is limited

Evolution 1. Food 2. Nest space C. Since resources are limited competition exists 1. Food 2. Nest space 3. Mates D. All populations show variability 1. Due to random mutations

Evolution 2. Some are favorable 3. Some are not favorable E. Those individuals w/ favorable variations will survive and reproduce 1. Genes for favorable variations are passed on 2. Those w/o favorable variation do not survive 3. = SURVIVAL OF THE FITTEST

VI. Evidence for Evolution A. Fossil Record 1. Extinct species a) over 99% of all species that ever lived are now extinct b) earth only has so much room

Archaeopteryx Small Dinosaur Teeth Wings with Feathers Reptile? Bird?

2. Radiometric Dating a) 1/2 life of elements in rocks where fossils are found tells age of fossil b) different elements have different 1/2 lives Half Lives of Elements

B. Embryology 1. Organisms pattern of development reflects prior ancestors (generally) a) all vertebrates have tails & gill slits at some point in development 2. Closely related species show similar development patterns

C. Selective breeding shows genetic diversity 1. People have been selectively breeding animals & plants for centuries

Selective Breeding

D. anatomy 1. Closely related species have similar structures 2. Homologous structures= structures with same origin 3. Closely related species have very similar homologus structures homologous structures 4. Analogous structures= structures with same function but different origin

ie: Bird wings and insect wings 5. Vestigial Structures ie: appendix

E. Biochemical Evidence 1. DNA a. closely related species have similar DNA codes 2. Amino Acid sequences

vii. Patterns of Evolution A. Divergent Evolution 1. Related species become different over time due to isolation a) random mutations in both

B. Adaptive Radiation 1. One species gives rise to several 2. Often seen on islands 3. New islands have many open niches 4. Competition is reduced Example: Galapagos Finches

Darwin’s Finches

C. Convergent Evolution 1. Unrelated species living in same type of habitat end up looking alike 2. Random mutations occur in both places and the good ones are passed on 3. The same adaptations are favorable in both locations Examples: North American Placentals and Australian Marsupials

Convergent Evolution

onverge.htm

Convergent Evolution

D. Co-evolution 1. Two unrelated species develop adaptations towards each other Example: Insects and Flowers

Coevolution