Natural Selection
Natural Selection
Evolution I
Evolution II
Natural selection and evolution
100
What is natural selection?
Species that are best adapted to their environment are able to reproduce
100
Fill in the blank: survival of the _____
Fittest
100
Which type of evidence (structural or molecular) is most helpful in making decisions about relationships between species?
Molecular (comparing DNA/protein sequences)
100
True or false: evolution happens quickly and can change in one generation
False
100
Modern species evolved from earlier, different species and share a _________ ___________.
Common ancestor
200
What is an adaptation?
Any inherited characteristic that increases an organisms chance of survival
200
True or false: all living things on earth, alive and extinct, came from the first species to walk the earth
True
200
Species that cannot adapt to changes in their environment become __________.
Extinct
200
what is evolution?
When a population changes over time to better suit their environment
200
Are mutations random?
Yes
300
What does fitness mean?
Fitness refers to the relative ability of an organism to survive and reproduce in a given environment.
300
Explain which mouse is better adapted to this environment.
The grey mouse is better adapted to this environment. Its fur color blends in with the environment and therefore is not seen by predators.
300
Differences among physical traits of organisms in the same species
What is variation?
300
What is a population?
A species that lives and inbreeds within a specific area
300
What are the four components of natural selection?
Variation, Inheritance (reproduction), Survival, Adaptation
400
Explain the peppered moth story. How did peppered moths change and why?
•Before the Industrial Revolution, the light peppered moth was common, while the dark form was very rare. The light moths blended in with the light-colored trees. However, the Industrial Revolution changed the tree colors.
•Over time, the dark colored moths became the more common of the two color forms. Natural selection favored the dark individuals, so they were more successful after the trees changed
400
What is the evidence for common ancestry? name two
Homologous structures, fossil record, embryology and development and DNA/protein comparison
400
Fill in the blank: Organisms with traits that _____ their chances of surviving and reproducing in their environment tend to leave more offspring
Increase
400
How is embryology proof of evolution?
Many organisms of different species look similar during early stages of development.
400
What is a homologous structure and what does it suggest? Give an example.
Homologous structures are similar physical features in organisms that share a common ancestor, but the features serve completely different functions. An example of homologous structures are the limbs of humans, cats, whales, and bats.
500
Bacteria often become resistant to harmful agents much more quickly than plants or animals. Which of the following best explains why?
a) Bacteria reproduce through asexual reproduction, which allows them to reproduce more quickly than plants or animals.
b) Bacteria reproduce asexually, so their offspring are not changed by mutations.
c) Bacteria reproduce sexually, increasing the variation within their populations.
d) Bacteria have a protective covering that makes them instantly immune to harmful agents.
a) Bacteria reproduce through asexual reproduction, which allows them to reproduce more quickly than plants or animals.
500
True or false : populations evolve, not individuals.
True
500
Fill in the blank: Natural selection over many generations causes ______
Evolution
500
How does natural selection of this population cause evolution?
The environment chooses the gray mouse trait to be more advantageous in this population. Over time, this population will change because the gray mouse trait will become more common than the tan mouse trait.
500
“Stronger organisms are more fit than weak ones.”
Explain why this statement is incorrect.
Fitness is determined by who is better adapted to survive in a particular environment and who can pass on their genes. Stronger is not always better.