- Slides: 11
Evolution Descent with Modification Charles Darwin
What Darwin Saw l l l Populations don’t grow out of control Limited Resources for organisms This causes competition for resources
What Darwin Saw Cont… l l Populations have genotype and phenotypic variation Your phenotype determines if you survive l l Ex: Tall enough to reach the food on the higher branches Ex: Camouflaged so predators don’t see you
So some survive are some don’t = Fitness l They pass on their genes and the next generation looks like the parents l
How we know… l Fossil Record l l Patterns in the fossil record show the evolution of species and descent from a common ancestor Homologous Structures l Structures that are common between different species who share a common ancestor
Homologous structures Compare the bone structure of different mammals… l Same structure l Came from common ancestor l
Fossil Record l l l Through the fossil record a history of organismal evolution is seen. Whale and horse Layers in the Earth/Radiometric Dating of fossils.
Natural Selection l Primary mechanism of evolution l All populations have genetic variation l l We don’t all look identical, genetically or physically Genotype=Phenotype
Fitness l It’s about how much one individual contributes to the gene pool of the next generation…. l You need to reproduce and have offspring to be considered “fit” l The characteristics that make you fit are different depending on the environment you live in.
Natural Selection & Evolution Lead to New Species