* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Evolution
Survey
Document related concepts
Natural selection wikipedia , lookup
Unilineal evolution wikipedia , lookup
Hindu views on evolution wikipedia , lookup
The Descent of Man, and Selection in Relation to Sex wikipedia , lookup
Evolutionary history of life wikipedia , lookup
Evidence of common descent wikipedia , lookup
Paleontology wikipedia , lookup
Acceptance of evolution by religious groups wikipedia , lookup
Transitional fossil wikipedia , lookup
Creation and evolution in public education wikipedia , lookup
Punctuated equilibrium wikipedia , lookup
Hologenome theory of evolution wikipedia , lookup
Catholic Church and evolution wikipedia , lookup
Transcript
Evolution Fixed Species Concept The creator had designed each and every species for a particular purpose. Result No evolution. Created the viewpoint that all species could be identified and named (Taxonomy). A major factor in the Linnaeus classification system. Theory Fossils were the remains of species lost due to catastrophe. No new species originated; species could only be lost over time. Result - No evolution. James Hutton 1795 - Gradualism Profound change is the cumulative product of slow, but continuous processes. Result Changes on the earth were gradual, not catastrophic. Charles Lyell 1797 - 1875. Incorporated Hutton’s gradualism into a theory called Uniformitarianism. Uniformitarianism Geological processes have operated at the same rate over the Earth’s history. Result The Earth must be VERY old. (much older than 6000 years of the fixed species concept). Idea that slow and subtle processes can cause substantial change. Jean Baptiste Lamarck Published theory in 1809. Theory - Life changed from simple to complex over time. Lamarck Fossils were the remains of past life forms. Evolution did occur. Lamarck’s Mechanisms 1. Use and Disuse Body parts used to survive become larger and stronger. Body parts not used to survive deteriorate. Lamarck’s Mechanisms 2. Acquired Characteristics Modifications acquired by use/disuse were passed on to offspring. Lamarck’s Mechanisms 3. Natural Transformation of Species ….species changed with every generation… extinction never occurred, organisms simply changed overtime. Problems with Lamarck’s Theory No knowledge of genetics. Acquired traits are not transmitted offspring. To Lamarck’s Credits Did suggest correctly the role of fossils in evolution. Did suggest that adaptation to the environment is a primary product of evolution. Charles Darwin Father of the modern theory of evolution. Theory Descent with Modification. Darwin's Background Trained as a Naturalist (after trying religion and medicine). Voyage of the Beagle Result Darwin's training and travel opportunities allowed him to formulate and support his ideas on Natural Selection. Galapagos Finches Galapagos Islands Unique animals Marine Iguana Tortise Alfred Wallace - 1858 Paper on Natural Selection identical to Darwin's ideas. Result - July 1, 1858 Dual presentation of the Wallace-Darwin ideas to the Linnaean Society of London. Darwin - 1859 Publication of "The Origin of Species” Comment Darwin best remembered for the theory because of his overwhelming evidence and because he published. Darwinian View History of life is like a tree with branches over time from a common source. Current diversity of life is caused by the forks from common ancestors. Example “The Origin of Species” Documented the occurrence of evolution. Suggested that the mechanism for evolution was Natural Selection. The Facts: Fact 1 All species reproduce themselves exponentially. Fact 2 - Most populations are normally stable in size. Fact 3 - Natural Resources are limited (finite). Inference 1 The large number of offspring must compete for the finite resources. Result - Most offspring die. More Facts Fact 4 - No two individuals in a population are exactly alike. Fact 5 - Variation is inheritable. Inference 2 Those individuals whose inherited characteristics fit them best to their environment survive and reproduce. Inference 3 Offspring inherit the favorable characteristics. Populations shift over time as the favorable characteristics accumulate. Nature Determines which characteristics are favorable. Determines who survives. Result - “Natural Selection” Natural Selection in action Artificial Selection When man determines the characteristics that survive and reproduce. Result - the various breeds of animals and plants we’ve developed. Ex - Mustard Plant Original Cultivars Evolution Success Measured By Survival Reproduction Whoever lives long enough and has kids is the “winner” in evolution. Requirements In order for Natural Selection to work, you must have: Long periods of time. Variations within a population. Subtleties of Natural Selection 1. Populations are the units of Evolution. 2. Only inherited characteristics can evolve. Comment Acquired characteristics may allow a species to evolve "outside" of Natural Selection. Ex: culture, learning Evidences of Evolution 1. Biogeography 2. Fossils 3. Taxonomy 4. Comparative Anatomy 5. Comparative Embryology 6. Molecular Biology Biogeography The geographical distribution of species. Problem: Species mixtures on islands Marsupials in Australia Evolution Viewpoint Biogeographical patterns reflect descent from the ancestors that colonized that area. Fossils Relics or impressions of organisms from the past. Problem: Show changes over time from simple to complex. Many fossils don't have descendants. Evolution Viewpoint Life has changed over time. Many species failed to survive and became extinct. Comments 1. Fossilization is a rare event. 2. Only hard parts fossilize well. 3. Problem in finding fossils. 4. Interpretation. 5. Missing Links. Taxonomy Science of Classification. Main Categories Kingdom Phylum Class Order Family Genus Species or Division Comparative Anatomy Problems 1. Homologous Structures Common "building plan” with divergent functions. Mammal forelimbs Comparative Anatomy Problems 2. Vestigial Organs Rudimentary structures of marginal, if any, use. Whale Legs Human Example Evolution Viewpoint Remodeling of ancestral structures as their functions or adaptations changed. Comparative Embryology Problem - closely related organisms go through similar stages in their embryonic development. Ex: Gill pouches in vertebrates Evolution Viewpoint Ontogeny is a replay of Phylogeny. (Development reflects descent) Molecular Biology Study of Evolution at the DNA or protein levels. Problem - related species have similar DNA sequences. Evolution Viewpoint Related species share a common ancestrial DNA. The closer the relationship, the more similar the DNA sequences should be.