Question

darwins natural selection worksheet name alexander m 10/30/25

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?
darwins 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.

Explanation:

• Part a:
• Natural selection selects against the diurnal worms because they are being eaten by the birds.
• It selects for the nocturnal worms as they are not being eaten (hidden in burrows during the day when birds eat) and thus have a better chance of survival and reproduction.
• Darwin's 5 points:
• Population has variations: There are two types of worms - nocturnal and diurnal.
• Some variations are favorable: The nocturnal trait is favorable as nocturnal worms avoid being eaten by birds.
• More offspring are produced than survive: Each spring, worms have about 500 babies but only 100 become old enough to reproduce.
• Those that survive have favorable traits: The surviving worms (assuming a higher proportion of nocturnal ones as diurnal are eaten) have the favorable nocturnal trait.
• A population will change over time: Over generations, if the diurnal worms keep getting eaten and nocturnal ones keep surviving and reproducing, the proportion of nocturnal worms in the population will increase.

Answer:

• a.
• AGAINST: Diurnal worms
• FOR: Nocturnal worms
• Darwin's 5 points:
• Population has variations: There are nocturnal and diurnal worms.
• Some variations are favorable: Nocturnal worms are not eaten (favorable).
• More offspring are produced than survive: 500 babies but only 100 reproduce.
• Those that survive have favorable traits: Surviving worms (likely more nocturnal) have favorable trait.
• A population will change over time: Nocturnal worms' proportion may increase.