* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Theory of Evolution - Solon City Schools
Survey
Document related concepts
The Selfish Gene wikipedia , lookup
Hologenome theory of evolution wikipedia , lookup
Theistic evolution wikipedia , lookup
Sexual selection wikipedia , lookup
Evolutionary mismatch wikipedia , lookup
Saltation (biology) wikipedia , lookup
Paleontology wikipedia , lookup
Sociobiology wikipedia , lookup
The Expression of the Emotions in Man and Animals wikipedia , lookup
Acquired characteristic wikipedia , lookup
Evolving digital ecological networks wikipedia , lookup
Genetics and the Origin of Species wikipedia , lookup
Inclusive fitness wikipedia , lookup
Natural selection wikipedia , lookup
The Descent of Man, and Selection in Relation to Sex wikipedia , lookup
Transcript
Theory of Evolution Chapter 15 What is Evolution? • Change over time • The process by which modern organisms have descended from ancient organisms 2 Competing Theories: Darwin and Lamarck Darwin and Lamarck agreed on a few things… • Life is still changing • Living things become better suited to their environment • All organisms are related • Simple Complex Lamarck • Organisms can change the shape or size of organs depending on how they use them • Acquired characteristics could be inherited. – If an animal altered its body during its lifetime, that change will pass to offspring • Organisms have a tendency toward perfection Darwin Inherited Variation and Artificial Selection • Artificial Selection: nature provides the variation and humans select those variations they find useful • Darwin had no idea how heredity actually worked Evolution by Natural Selection • Darwin wanted to compare processes in nature to artificial selection – The struggle for existence – Survival of the fittest – Descent with modification The Struggle for Existence • High birth rates and shortage of basic needs would force organisms to compete • Struggle for Existence: each species compete regularly to obtain food, living space, and other necessities of life. Survival of the Fittest • How well suited is an organism to its environment? • Fitness: the ability of an individual to survive and reproduce in its specific environment • Darwin proposed that fitness is a result of adaptations • Individuals that are better suited to their environment survive and reproduce most successfully Natural Selection • Only certain individuals of a population reproduce • In natural selection, traits being selected contribute to fitness in the environment • Natural selection results in changes in inherited characteristics in a population Lamarck- why was he wrong?? – Lamarck did not know how traits were inherited – He did not know that an organism’s behavior has no effect on the traits it passes down – Acquired characteristics are not passed on to offspring, – Organisms do not get what they "need" through "inner wants" or through "use and disuse” Individual intentions do not play a role. – Instead, the animals well suited survive and reproduce while those ill suited die