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Evolution Part I. BIO 2215 Oklahoma City Community College Dennis Anderson. Evolution. Changes in a population over time. Does the idea of evolution contradict a belief in God?. Many scientists of all religious faiths believe in both.
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Evolution Part I BIO 2215 Oklahoma City Community College Dennis Anderson
Evolution • Changes in a population over time
Does the idea of evolution contradict a belief in God? • Many scientists of all religious faiths believe in both. • Some people feel evolution contradicts the literal interpretation of the Bible.
Earths Position in the Universe • 400 years ago the general public thought that the earth was the center of the universe • Sun revolves around the earth • The earth does not move
Galileo and Corpernicus • Demonstrated scientific evidence that the sun is at the center of our solar system and the earth moves around the sun
Galileo and the Church • Religious leaders felt the heliocentric theory (sun at the center) was a direct contradiction to the literal interpretation of the Bible • Galileo found guilty of heresy
Copernican System (Heliocentral Theory) • Did not destroy peoples belief in God • Public now accepts the overwhelming evidence for the heliocentric theory
Theory of Evolution • Science has overwhelming evidence that all life is constantly evolving
Ostrich in Africa Rhea in South America
Natural Selection • One mechanism of evolution • Main concepts of natural selection • Overproduction of offspring • Inherited variation in offspring • Competition • Best adapted in a given environment survive and reproduce to increase their kind • They are naturally selected
Overproduction of Offspring • Elephants (very slow reproductive rate) • If all the offspring of one elephant pair survive and all their offspring survive then: • 750 years = 19,000,000 elephants • 1200 years = Enough elephants to cover the earth! • Beetles • A handful that weighs 10 mg each • 82 weeks • 61,000,000,000,000,000,000,000 ton • The weight of the earth!
Variation of Offspring • Offspring of the same parents are different from each other
Competition • Since more individuals are born than can survive for an extended period of time, they compete for resources • Food • Living space • Mates
Best adapted to a given environment are selected to survive • Brown bears • Adapted to survive in Oklahoma • Polar bears • Adapted to survive in Alaska
Artificial Selection Collie Sheltie
Evolution is Change • Changing alleles in a population can produce new species • Dogs have evolved from wolves • Man has artificially selected traits to produce the various dog breeds • Nature uses natural selection and other mechanisms for evolution
Scientific Disciplines That Give Evidence for Evolution • Paleontology • Comparative anatomy • Biogeography • Molecular biology • Others
Paleontology • Study of fossils • Allows us to see anatomical similarities between living species and organisms that lived in the past • Allows us to see how life has changed over time
Life Has Changed • Millions of species have been found that are different from life today
50 MYA 30 MYA 15 MYA Modern 50 Million Years of Change
Homologous Structures • Same structures used for different purposes
HomoplasyAnalogous Structures Similar structures due to convergent evolution,
Molecular Biology • The study of the molecules of life including DNA and proteins
Homeobox or HOX • First discovered in fruit flies in 1983 • Later found in mice, man and other organisms • Controls embryonic development of different body regions
Evolution of New Body Plan • Hox gene Ubx of crustacean mutated in lab • Caused suppression of leg development • Mechanism for evolution of insect body plan 400 MYA
Comparing DNA • Human DNA compared to: • Chimpanzee 99% same • Gorilla 97.7% same • Orangutan 96.3% same • Another human 99.9% same
Comparing Protein Sequences • Many proteins in all of man are identical • Organ transplants require similar proteins in the donor and the recipient • A sibling or parent is often the best source for an organ transplant