Darwin’s Natural Selection Worksheet Name ___________________________________
Read the following situations below and identify the 5 points of Darwin’s natural selection.
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? Diurnal worm
FOR? Nocturnal worms
b. Darwin's 5 points: Identify the 5 points in the scenario above.
Population has variations. Nocturnal and diurnal worms
Some variations are favorable. Nocturnal worms
More offspring are produced than survive. 100 out of 500 survive
Those that survive have favorable traits. nocturnal
A population will change over time. noctural worms
2) There are 3 types of polar bears: ones with thick coats, ones with thin coats
and ones with medium coats. It is fall, soon to be winter. The temperatures
are dropping rapidly and the bears must be kept warm, or they will freeze to
death. Many of the bears have had ~2 cubs each but due to the extreme
temperatures, many mothers only have one cub left.
a. What bear will natural selection select AGAINST? __________________ FOR? ________________
b. Darwin's 5 points: Identify the 5 points in the scenario above.
Population has variations. _________________________________________________________________
Some variations are favorable. _____________________________________________________________
More offspring are produced than survive._________________________________________________
Those that survive have favorable traits. ____________________________________________________
A population will change over time. ________________________________________________________
