Science - 2018-19

LS.13 - Changes of Populations

The student will investigate and understand that populations of organisms change over time. Key concepts include

a) the relationships of mutation, adaptation, natural selection, and extinction;

b) evidence of evolution of different species in the fossil record; and

c) how environmental influences, as well as genetic variation, can lead to diversity of organisms.

Bloom's Levels:  Analyze; Understand

Adopted: 2010

BIG IDEAS

  • Groups of organisms change over time.
  • The scientific theory of evolution is the organizing principle of life science and is supported by multiple forms of evidence..
  • Natural selection is a primary mechanism leading to change over time in organisms.

  • I can explain the causes of genetic disorders, such as Down Syndrome.
  • I can trace a bird alive today to the dinosaurs.
  • I can explain why fish appear in various colors based on their location.

UNDERSTANDING THE STANDARD

  • The mechanisms through which evolution takes place are a related set of processes that include mutation, adaptation, natural selection, and extinction. This results in changes in populations of organisms over time.
  • Mutations are inheritable changes because a mutation is a change in the DNA code.
  • Adaptations are structures, functions, or behaviors that enable a species to survive.
  • Natural selection is the survival and reproduction of the individuals in a population that exhibit the traits that best enable them to survive in their environment. 
  • A mutation may result in a favorable change or adaptation in genetic information that improves a species’ ability to exist in its environment, or a mutation may result in an unfavorable change that does not improve or impedes a species’ ability to exist in its environment.
  • The evidence for evolution is drawn from a variety of sources of data, including the fossil record, radiometric dating, genetic information, the distribution of organisms, and anatomical and developmental similarities across species.
  • Individuals of a population each exhibit a range of variations in a trait as a result of the variations in their genetic codes. These variations may or may not help them survive and reproduce in their environment.
  • If a species does not include traits that enable it to survive in its environment or to survive changes in the environment, then the species may become extinct.

ESSENTIALS

In order to meet this standard, it is expected that students will

a)  describe how changes in the environment can bring about changes in a species (adaptation, extinction) through natural selection.

b)  describe and explain how fossils are records of organisms and events in Earth’s history.

explain the evidence for evolution from a variety of sources of scientific data.

c)  explain how genetic variations in offspring, which lead to variations in successive generations, can result from the same two parents.

a, b, c)  interpret data from simulations that demonstrate selection for a trait belonging to species in various environments.

analyze and evaluate data from investigations on variations within a local population.

explain how environmental influences, as well as genetic variation, can lead to diversity of organisms.


KEY VOCABULARY

mutuation, adaptation, natural selection, extinction, evolution, fossil record, radiometric dating, genetic information, fossil, fossil record, relative dating

Updated: Jun 29, 2018