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Evolution Part I. Evolution. Changes in a population over time. 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.
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Evolution • Changes in a population over time
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 crossed with Scandinavia Spitz 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
Which would be the closest protein match for an organ transplant?Assuming all are alive and healthy. • A persons father • A persons great grandfather • A persons 10th great grandfather