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This lesson will increase your knowledge of concepts covered in the following TEKS for biology:. 3.a Analyze, review, and critique scientific explanations, including hypotheses and theories, as to their strengths and weaknesses using scientific evidence and information
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This lesson will increase your knowledge of concepts covered in the following TEKS for biology: 3.a Analyze, review, and critique scientific explanations, including hypotheses and theories, as to their strengths and weaknesses using scientific evidence and information 3.c – Evaluate impact of research on scientific thought, society, and the environment 6.c – Identify and illustrate how changes in DNA cause mutations and evaluate the significance of these changes 6.d – Compare genetic variations observed in plants and animals 7.a – Identify evidence of change in species using fossils, DNA sequences, anatomical similarities, physiological similarities, and embryology
This lesson will increase your knowledge of concepts covered in the following TEKS for biology: 7.b – Illustrate the results of natural selection in speciation, diversity, phylogeny, adaptation, behavior, and extinction 12.c – Compare variations, tolerances, and adaptations of plants and animals in different biomes 12.d – Identify and illustrate that long-term survival of species is dependent on a resource base that may be limited 13.a – Evaluate the significance of structural and physiological adaptations of plants to their environment
Overview of Lesson • Science versus religion? • Big Bang Theory and origin of life on Earth • Theory of evolution • Evidence for evolution
Yesterday’s Controversy Galileo’s View of the Solar System Galileo agreed with the Copernican view that the sun and not the earth was the center of the solar system The Catholic Church believed in the Ptolemaic system that the earth was the center of the universe For his view, Galileo was sentenced to house arrest for the last 9 years of his life
In 1980s, Pope John Paul II moved to correct a 350 year old wrong From: Time, March 12, 1984
“The intention of the Holy Spirit is to teach how to go to heaven and not how go the heavens.” Galileo allegedly said, quoting a churchman of his day
Today’s Controversy Darwin’s View of Evolution Charles Darwin believed that species evolved from early ancestors by natural selection The Catholic Church believed that all species were created as they exist today For publishing “On the Origin of Species” in 1859, he has been criticized
Creationists tried to block the teaching of evolution using lawsuits • Opponents of Darwinian evolution move to teach strength and weaknesses, and include Intelligent Design as an alternative • Scientists defending evolution as the only supported explanation From: Time, August 23, 1999
Science’s view of evolution & religion • According to Dr. Stephen Jay Gould, a prominent evolutionist • evolution is fact, supported by evidence • produced by the work of thousands of • scientists for over 200 years • there should be no rift between science and • religion, they ask different questions • both realms hold equal worth
Some religions accept evolution The Catholic Church believes we should not interpret Genesis literally From: Time, November 4, 1996
Overview of Lesson • Science versus Religion? • Big Bang Theory and origin of life on Earth • Theory of evolution • Evidence for evolution
Big Bang Theory • Universe is expanding • If we know the distance between galaxies and speed that the galaxies are moving apart, we can back calculate when the universe began • First estimate of the age of the universe was 20 billion years old
Astronomers keep refining their calculations as technology improves Earth Age 4.5 billion Solar System Age 4.5 billion Age of Universe Estimated 8-12 bill Revised 12-14 bill Pinpointed to 13.7 bill From: Time, November 7, 1994
Origin of Life: Scientific Hypothesis Earth began as a lifeless planet about 4.5 billion years ago Life arose on the planet spontaneously
For life to form spontaneously… • Primitive Earth’s chemicals had to • combine to form organic molecules • Organic molecules had to combine to • form primitive cells (protocells) • Primitive cells had to evolve into a • true cells
Evidence that organic molecules could form spontaneously Dr. Stanley Miller created organic molecules using gasses and electricity Based on: Mader, S., Inquiry Into Life, McGraw-Hill
Chemical evolution led to the formation of protocells Based on: Mader, S., Inquiry Into Life, McGraw-Hill
There is evidence that microspheres (protein spheres) could form spontaneously Based on: Mader, S., Inquiry Into Life, McGraw-Hill
There are still many unanswered questions Big Gap Based on: Mader, S., Inquiry Into Life, McGraw-Hill
Early cellular life then evolved into more complex life forms
Overview of Lesson • Science versus religion? • Big Bang Theory and origin of life on Earth • Theory of evolution • Evidence for evolution
Voyage of Charles Darwin -22 year old naturalist -1830s
Darwin’s Contribution to the Theory of Evolution • Darwin collected data for 20 years • Published On the Origin of Species • Hypothesized process of natural selection and its role in the origin of species • His hypothesis has been constantly tested, yielding information that forms the foundation for modern biology
Lamarck’s Concept 1 2 3 Based on: Mader, S., Inquiry Into Life, McGraw-Hill • Early giraffes had short necks that they stretched for food • The longer necks were passed on to their offspring, who then stretched them more • Eventually only long-necked giraffes existed
Darwin’s Theory of Natural Selection 1 2 3 Based on: Mader, S., Inquiry Into Life, McGraw-Hill • Early giraffes had necks of various lengths • Natural selection due to competition lead to survival of the longer-necked giraffes and their offspring • Eventually only long-necked giraffes survived the competition
“There is a grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one: and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved.” Charles Darwin, last sentence of On the Origin of Species
Evolution Change in the genetic makeup of a population through time, sometimes leading to formation of new species
New species form after a geographic barrier prevents gene flow Based on: Mader, S., Inquiry Into Life, McGraw-Hill
Overview of Lesson • Science versus religion? • Big Bang Theory andorigin of life on Earth • Theory of evolution • Evidence for evolution
Earth is very old, providing time for evolution to have occurred • Radioactive dating shows • the earth is 4.5 billion • years old • Because of continental • drift, there has been a long • time for different • organisms to evolve on • different continents Based on: Mader, S., Inquiry Into Life, McGraw-Hill
Fossil Evidence: allows reconstruction of evolutionary trees Based on: Mader, S., Inquiry Into Life, McGraw-Hill
Extinction is evidence for natural selection “An estimated 99 percent of all species that ever lived are extinct.” The Diversity of Life, National Geographic
Domestication of animals and plants shows the power of artificial selection Wolf Dixie Photo courtesy of Texas Parks and Wildlife Department
Anatomical Evidence Anatomical similarities suggest common descent Here all vertebrate forelimbs contain the same set of bones Based on: Mader, S., Inquiry Into Life, McGraw-Hill
Embryological Evidence A unity of body plan shared by vertebrates extends to their embryological development, suggesting common descent Based on: Mader, S., Inquiry Into Life, McGraw-Hill
DNA Evidence: it operates the same way in all organisms, suggesting it is the common thread tying all organisms together, from bacteria to humans T - A Controls Protein Production C - G A - T
Fig. 27.6 Other Molecular Evidence Based on: Mader, S., Inquiry Into Life, McGraw-Hill
View of Most Scientists • Universe began with the Big Bang • Earth is 4.5 billion years old • Life arose on earth spontaneously • Earliest life were bacteria • Genetic drift and natural selection pressures caused changes in genetics of populations • Millions of species arose on earth over billions of years