Darwin’s Natural Selection Worksheet
Name: _________________________________
Read the following situations below and answer questions.
1. There are 2 types of worms: worms that eat at night (nocturnal) and worms that eat
during the day (diurnal). The birds eat during the day and seem to be eating ONLY
the diurnal worms. The nocturnal worms are in their burrows during this time. Each
spring when the worms reproduce, they have about 500 babies but only 100 of these
500 ever become old enough to reproduce.
a. What worm has natural selection selected AGAINST? _____________ FOR?_________________
b. Darwin's 5 points: Identify the 5 points in the scenario above.
Population has variations. What are the variations in this population?
________________________________________________________________________________
Some variations are favorable. What variation is favorable? ________________________________
More offspring are produced than survive. _____________________________________________
Those that survive have favorable traits.
_______________________________________________
A population will change over time. How will this population change over time?
__________________________________________________________________
__________________________________________________________________
c. What type (directional, disruptive, stabilizing) of selection is this?
___________________________
2. There are 3 types of plants: tall, medium, and short. During the growing season, the
short plants have a hard time competeing for sunlight and the tall plants receive a
lot of damage from the wind. The Plants make thousands of seeds, but only a few
survive because there is too much competition for space in the meadow.
a. What plant has natural selection selected AGAINST?________________ FOR?____________________
b. Darwin's 5 points: Identify the 5 points in the scenario above.
Population has variations. What are the variations in this population?
________________________________________________________________________________
Some variations are favorable. What variation is favorable? ________________________________
More offspring are produced than survive. _____________________________________________
Those that survive have favorable traits. _______________________________________________
A population will change over time. How will this population change over time?
________________________________________________________________________________
c. What type (directional, disruptive, stabilizing) of selection is this? ___________________________
3. There are three types of rabbits: Black, grey, and white in fur color. This population of
rabbits lives in an area that had very dark black rocks as well as very white colored stone, the
rabbits with black fur would be able to hide from predators amongst the black rocks and the
white furred rabbits would be able to hide in the white rocks, but the gray furred rabbits would
stand out in both of the habitats and would suffer greater predation. The rabbits have had
babies all year long but many are eaten by foxes or hawks. Due to drought, many have starved
to death.
a. What rabbit has natural selection selected AGAINST?_______________ FOR?____________________
b. Darwin's 5 points: Identify the 5 points in the scenario above.
Population has variations. What are the variations in this population?
________________________________________________________________________________
Some variations are favorable. What variation is favorable? ________________________________
More offspring are produced than survive. _____________________________________________
Those that survive have favorable traits. _______________________________________________
A population will change over time. How will this population change over time?
________________________________________________________________________________
c. What type (directional, disruptive, stabilizing) of selection is this? ___________________________
4. Bob believes that giraffes have long necks because they have stretched their necks to try and
reach food that is high in trees. Since the parent had stretched its neck, it passed the long
neck on to its offspring.
Ryan believes that giraffes have long necks because the ones with long necks were able to
reach the food, and those with short necks could not and died. The long necked giraffes
reproduced, and soon all of the giraffes had long necks.
a. Who thinks like Lamarck?_____________________________________________________
b. Who thinks like Darwin? ______________________________________________________
c. Who disproved the idea of inheritance of acquired traits using tailless mice?
__________________________________________________________________________________________