Variation & Traits
Survival & Reproduction
Evidence & Data
Vocabulary
Applying the Concept
100
What is genetic variation?
DIFFERENCES IN TRAITS AMONG INDIVIDUALS IN A POPULATION
100
Natural selection acts directly on ----
TRAITS
100
If a graph shows an increase in a trait over time, what does that suggest?
THE TRAIT IS ADAPTIVE, PROVIDING A SURVIVAL OR REPRODUCTIVE ADVANTAGE
100
makes it more likely that an organism will survive in its environment
ADAPTIVE TRAIT
100
If a drought occurs, which plants are more likely to survive?
THOSE THAT CAN CONSERVE OR STORE WATER
200
Why is variation necessary for natural selection?
WITHOUT VARIATION, THERE ARE NO DIFFERENT TRAITS TO SELECT FOR OR AGAINST.
200
What must happen for a trait to become more common in a population?
INDIVIDUALS WITH THAT TRAIT MUST SURVIVE AND REPRODUCE MORE.
200
If predator speed increases over generations, what might happen to prey speed?
PREY SPEED MAY ALSO INCREASE DUE TO SELECTIVE PRESSURE (FROM THE PREDATOR; FASTER PREY WILL SURVIVE, REPRODUCE AND PASS ON THEIR GENES
200
hiding by looking the same as the envrionmental background
CAMOUFLAGE
200
If a species becomes faster over generations, what does that suggest?
SPEED IS ADAPTIVE BECAUSE FASTER INDIVIDUALS SURVIVED AND REPRODUCED MORE
300
What causes variation in a population?
MUTATIONS AND RECOMBINATION (INHERITANCE OF DIFFERENT ALLELE COMBINATIONS).
300
Does natural selection work on individuals or populations? Explain.
INDIVIDUALS SURVIVE OR DIE, BUT POPULATIONS CHANGE OVER TIME.
300
Trait distribution in a population shifts, with one trait decreasing in distribution while another increases. What kind of evidence would you look for to explain this change?
CHANGES IN ENVIRONMENT (I.E. PREDATOR, CLIMATE, ETC)
300
bar graph that shows how traits are distributed in a particular populations
HISTOGRAM
400
If all individuals in a population are identical, what happens when the environment changes?
THE POPULATION IS AT HIGH RISK BECAUSE INDIVIDUALS MAY NOT HAVE TRAITS ADAPTIVE TO THE NEW ENVIRONMENT.
400
A frog was born with a mutation for a slightly longer tongue. The trait helps them catch fast insects. What do we expect to happen over generations?
THE LONG-TONGUE TRAIT INCREASES IN DISTRIBUTION DUE TO NATURAL SELECTION.
400
Explain what happened to this population of frogs.
FROGS THAT JUMPED FARTHER SURVIVED BETTER AND REPRODUCED MORE, BECOMING MORE COMMON IN THE POPULATION
400
random change to a gene that can sometimes result in a new trait
MUTATION
400
If the environment stays the same for many generations, what happens to variation?
ADVANTAGEOUS TRAITS WILL INCREASE, DISADVANTAGEOUS TRAITS WILL DECREASE; REDUCING VARIATION FOR THAT TRAIT
500
Why DO inherited traits matter more than learned behaviors in natural selection.
ONLY INHERITED TRAITS ARE PASSED TO OFFSPRING AND FUTURE GENERATIONS.
500
In natural selection, why is reproduction more important than survival?
REPRODUCTION PASSES DESIRABLE TRAITS TO FUTURE GENERATIONS.
500
Explain what happened to this population of frogs.
MUTATION INTRODUCED A NEW ADAPTIVE TRAIT-LEVEL 4 POISON. THE LEVEL 1 POISON DIED OUT BECAUSE IT WAS NON-ADAPTIVE.
500
process where distribution of traits in a population changes over generations due to environmental selection pressure
NATURAL SELECTION
500
A student says, “The fish evolved because they wanted to survive.” What is wrong with this statement?
NATURAL SELECTION IS NOT INTENTIONAL; INDIVIDUALS WITH ADAPTIVE TRAITS SURVIVE AND REPRODUCE MORE; IT IS BASED ON THE ENVIRONMENT