Vocabulary
A ___________ is a group of organisms that is able to mate and produce fertile offspring.
Species
Organisms that belong to the same __________ can typically interbreed and have babies.
Species
What is punctuated equilibrium?
One explanation about the rate of evolution--organisms evolve quickly after a change in the environment, but very slowly otherwise.
explain how the Kaibab & Abert Squirrels became different species.
Populations were isolated due to the grand canyon forming, then natural selection caused the populations to adapt differently to their environments.
Differences between members within a population are called...
Variations
In the process of natural selection, organisms that are better adapted to their environments are able to better survive and ____________.
reproduce (or make babies)
How can you tell how closely two organisms are related to each other?
2) if they possess homologous structures
A horse and a donkey can mate with eachother. Their offspring, called a mule, is not fertile. Do horses and donkeys belong to the same species? Explain your answer.
Nope. does not meet the definition of species.
Similar structures like bones and tissues--serves as one of the three pieces of evidence for evolution.
Homologous structures
Similarities in the early developmental stages of a chicken and pig embryo indicate that they share a ____________.
common ancestor
What is an adaptation--pick an animal and give at least 3 examples of its adaptations.
answer varies...
A scientist collects rabbits that live at sea level and moves them to the mountains. One year later, the same scientist finds that they now have larger lungs, which helps them breathe the thin mountain air. The scientist returns the rabbits to sea level. Will the offspring of these rabbits also have larger lungs (if born at sea level)?
No. Acquired characteristics cannot be inherited.
___________ is a trait that helps an organism survive in its specific environment.
an adaptation
Natural selection requires _____________, which are differences in traits across members of a population.
Variation
explain how natural selection works
The environment changes, individuals that have beneficial traits for the new environment are more likely to survive and reproduce than those who don't. They pass their beneficial traits to their offspring through their DNA, and eventually most of the population will have the beneficial trait.
Explain how a group of organisms that is separated from its population can evolve different traits.
explains natural selection.
__________ refers to the tendency for organisms producing more offspring than can survive.
Overproduction
The only traits that can be acted upon by natural selection are those that are controlled by__________.
DNA
What has to happen first for evolution to happen--how does new species generation start?
Populations need to be isolated.
How did studying selective breeding help Darwin discover his theory of natural selection?
He saw that traits can be inherited. Artificial selection is exactly the same process as natural selection... only not so natural. yada, yada, yada.