Read the scenario. Answer the following question: What changes in genetic traits have occurred in this rodent species? Explain why these changes have occurred.
68: Natural Selection
TEKS 7.110
Read the passage below and answer the following question.
A rodent species migrates to a mountainous environment with mild summers and
cold winters. Most of the rodents have a short, smooth coat, but some of the
rodents have a longer, fluffy coat. Many of the smooth-coated rodents die the first
winter because they cannot protect themselves from cold temperatures.
The rodents with longer, fluffy coats are able to stay warm and search for food
during the winter, increasing their chances for survival and reproduction. More and
more offspring are born with long, fluffy coats. Over time, the population of rodents
with long, fluffy coats increases while the smooth-coated rodent population
decreases. Smooth coats gradually become a rare trait in this population.
What changes in genetic traits have occurred in this rodent species? Explain why these
changes occurred
Your answer