Standard 32
SC.7.L.15.2
Explore the scientific theory of evolution by recognizing and explaining ways in which genetic variation and environmental factors contribute to evolution by natural selection and diversity of organisms.
Summary: This standard asks us to understand the theory of evolution. We should be able to explain how genetic variation and natural things that happen result in the "survival of the fittest" and species diversity.
Explore the scientific theory of evolution by recognizing and explaining ways in which genetic variation and environmental factors contribute to evolution by natural selection and diversity of organisms.
Summary: This standard asks us to understand the theory of evolution. We should be able to explain how genetic variation and natural things that happen result in the "survival of the fittest" and species diversity.
Vocabulary:
Evolution: A change over time. In biology, it is specifically referring to the change of organisms over time to be most successful in their environments
Natural Selection: is the gradual process by which heritable biological traits become either more or less common in a population as a function of the effect of inherited traits on the reproductive success of organisms interacting with their environment
Descent: the genetic differences that are heritable and passed on to the next generation
Genetic Variation: differences between individuals or differences between populations. Mutation is the ultimate source of genetic variation, but mechanisms such as sexual reproduction and genetic drift contribute to it as well
Diversity: the level of biodiversity, refers to the total number of genetic characteristics in the genetic makeup of a species
Environmental Factors: any factor, whether abiotic or biotic, that influences living organisms
Evolution: A change over time. In biology, it is specifically referring to the change of organisms over time to be most successful in their environments
Natural Selection: is the gradual process by which heritable biological traits become either more or less common in a population as a function of the effect of inherited traits on the reproductive success of organisms interacting with their environment
Descent: the genetic differences that are heritable and passed on to the next generation
Genetic Variation: differences between individuals or differences between populations. Mutation is the ultimate source of genetic variation, but mechanisms such as sexual reproduction and genetic drift contribute to it as well
Diversity: the level of biodiversity, refers to the total number of genetic characteristics in the genetic makeup of a species
Environmental Factors: any factor, whether abiotic or biotic, that influences living organisms
Biological evolution is not simply a matter of change over time. Lots of things change over time: trees lose their leaves, mountain ranges rise and erode, but they aren't examples of biological evolution because they don't involve descent through genetic inheritance. The central idea of biological evolution is that all life on Earth shares a common ancestor, just as you and your cousins share a common grandmother. Through the process of descent with modification, the common ancestor of life on Earth gave rise to the fantastic diversity that we see documented in the fossil record and around us today. Evolution means that we're all distant cousins: humans and oak trees, hummingbirds and whales. Without genetic variation, some of the basic mechanisms of evolutionary change cannot operate. There are three primary sources of genetic variation:
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Natural selection is one of the basic mechanisms of evolution, along with mutation, migration, and genetic drift.
Darwin's grand idea of evolution by natural selection is relatively simple but often misunderstood. To find out how it works, imagine a population of beetles:
http://evolution.berkeley.edu/evolibrary |