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Theory of Evolution. Mrs. Harlin. Whale Evolution. http://www.pbs.org/wgbh/evolution/library/03/4/quicktime/l_034_05.html. 3.4.1. Explain how fossil, biochemical, and anatomical evidence support the theory of evolution. Life.
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Theory of Evolution Mrs. Harlin
Whale Evolution http://www.pbs.org/wgbh/evolution/library/03/4/quicktime/l_034_05.html
3.4.1 • Explain how fossil, biochemical, and anatomical evidence support the theory of evolution.
Life • 1st appeared in the oceans between 3.9 and 3.4 billion years ago. • Urey and Miller’s “Primordial Soup” model proposed that life formed from organic molecules produced by solar radiation, volcanoes, and lightning.
Origin of Life • In the past, many believed in spontaneous generation, the idea that nonliving material can produce life.
Spontaneous Generation Disproved • In 1668, Italian physician, Francesco Redi, disproved that maggots and most large organisms did not arise spontaneously.
Louis Pasteur • In the mid-1800s, Pasteur disproved spontaneous generation of microorganisms, which led to belief in biogenesis.
Idea of Biogenesis • Biogenesis: living organisms only come from living organisms.
Evolution of Cells • 1st cells (most primitive life forms) • Anaerobic- no oxygen required • Prokaryotic- no nucleus
2 Groups of Prokaryotes • Archaebacteria- do not have a chemical called peptidoglycan in their cell walls. • Live in extreme environments. Some still live today. • Eubacteria- have a chemical called peptidoglycan in their cell walls. • Present day example- E. Coli • Earliest fossil bacteria dates back to over 2,500 million years ago (2.5 billion).
Cyanobacteria • Photosynthesizing archaebacteria. • Oxygen appeared in the atmosphere. • Led to ozone layer, which enabled evolution of eukaryotes.
The Endosymbiont Theory • Idea that eukaryotes evolved through a symbiotic relationship between ancient prokaryotes is called endosymbiosis. • Evidence- mitochondria and chloroplast have their own DNA.
Eukaryotes • The first were protists, unicellular and then multicellular. • From protists evolved fungi, plants, and animals. • Plants and fungi formed mycorrhizae, and were the first multicellular organisms to live on land. • Mycorrhizae- mutualism between plants and fungi; fungus provides minerals to plant, plant provides nutrients to fungus.
Eukaryotes • The first vertebrates to invade dry land were amphibians. • The extinction of many reptile species enabled birds and mammals to become the dominant vertebrates on land.
Evidence for Evolution • Fossils • Relative Dating- comparing the order of fossils in a rock layers • Absolute Dating- measuring chemical qualities of a fossil or rock layer that a fossil is found in.
Other Evidence for Evolution • Shared anatomical structures • Homologous structures- similar structures with a common evolutionary origin. • Vestigial structures- body structure in a present-day organism that no longer serves its original purpose.
Other Evidence for Evolution • Biochemical similarities- genetic makeup (DNA is always the best evidence to support relationships between organisms.)
The Little People of Flores • http://www.pbs.org/wgbh/nova/evolution/little-people-flores.html