Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Hologenome theory of evolution wikipedia , lookup
Genetics and the Origin of Species wikipedia , lookup
Theistic evolution wikipedia , lookup
On the Origin of Species wikipedia , lookup
Transitional fossil wikipedia , lookup
The eclipse of Darwinism wikipedia , lookup
The Expression of the Emotions in Man and Animals wikipedia , lookup
Chapter 15 { Evolution Evolution: change over time Scientific Theory: a well supported testable explanation of a phenomena that has occurred in the natural world 15-1 The Puzzle of Life’ Diversity Born in 1809 Has contributed the most to evolution set sail in 1831 from England lasted 5 years was the most important voyages in scientific history Charles Darwin Made many observations during his travel got this theory by investigating plants & animals in different places Galapagos Islands(off coast of S. America) Charles Darwin Noticed many animals were well suited to their environment Noticed some animals were only found in certain places even though other places had same ecosystem Charles Darwin Collected fossils He wondered where all these species had gone and who they might be related to… Charles Darwin The Galapagos Islands influenced Darwin more than any other place in the world The Galapagos Islands The Galapagos Islands Galapagos Islands were very close together But had very different climates. Smallest island was hot and dry and barren Others had rich vegetation and many animals like tortoises. Charles Darwin Darwin learned that the tortoises varied based on the island they came from Could be told apart by shell Also shape of a birds beak varied depending on island of origin The Galapagos Islands He wondered if these different animals had once been of the same family??? The Galapagos Islands In 1858 Alfred Wallace pushed him to publish thought because he to came up with same theories. Called On the Origin of Species. Darwin’s Book Artificial Selection- nature provides the variation, human selects the best to breed Natural Selection- change over time in inherited characteristics. “Survival of the fittest” Natural variation- differences among individuals of a species. Variation is inherited Darwin’s Ideas FitnessSurvival of the Fitness - Adaptations- special characteristics that make and organism well suited for a particular environment Cont. If disease affects only short people…what will happen If survivors all mated and reproduced what traits would offspring have? Mix because of heterozygous…short people would start to die out. In 1,000 years what do you expect? Only tall would survive an short wouldn’t be produced 1. Individual organisms differ some variation due to inheritance 2. Organisms produce more offspring than can survive and many that do survive don’t reproduce 3. More organisms are produced than can survive = competition for limited resources 4. Each organism had advantages & disadvantages Best suited survive and reproduce AND pass traits down 5. Species today are decedents with modifications from ancestral species. We are all united and thus we have common descendants Summary Cont. What did I evolve into??? Whale Guess???? Who am I related to???? Hermit Crab Why am I called Ice Fish Has antifreeze glycoprotein so survive in freezing water Some thought Darwin was crazy. People thought: the world was only a few hundred years old that all species were the same NOW as in beginning Rocks and geological features were created by catastrophic events that no human saw 15-2 Ideas that shaped Darwin’s thinking By the time he set sail new ideas were being formed by other scientists Hutton and Lyell the world was a few million years old not a few hundred. geological processes are still occurring today Ie volcanoes, erosion, earthquakes, sea floor being pushed up, mountains created Hutton and Lyell • recognized that living things change over time • all species are descendents from one another and that they adapt to their environment Lamarck Also that organisms acquire or lose traits in their lifetime. These traits can be passed to offspring Lamarck Cont. 1. Innate tendency towards perfection 2. Use and disuse continually changing can alter size and shape..add or remove features 3. Inheritance of acquired traits example: if parents grew longer…passed on to kids Lamarck Cont. Thomas Malthus 1798 If population continues to grow we will run out of food and space Malthus 1. Fossil records- gradual change over time 2. Geographical distribution of living species 3. Homologous structures of living organisms 4. Similarities in early development Evidence of Evolution and shared common ancestors