Admin What are the lighter colored frogs selected against?
Explain how natural selection will act on this population. The frogs with a mutation that gave them slightly lighter skin coloring have an advantage because they blend in more easily with their environment and escape their predators.
What part of the finch has changed over time?
beak
Which part of the finch has changed over time? The beak of the finch has changed over time.
What is required for a trait to become more common over time in a population?
If a trait results in more offspring who share the trait, then that trait is more likely to become common in the population than a trait that arises randomly. At the molecular level, selection occurs when a particular DNA variant becomes more common because of its effect on the organisms that carry it.
What happened to the number of light and dark moths in this simulation?
The number of light moths (red) decreased over the 10 year period, and the number of dark moths increased. These moths live in an area where the tree bark is dark.
How do you explain the changes in population of organisms through time?
Evolution is a process that results in changes in the genetic material of a population over time. Evolution reflects the adaptations of organisms to their changing environments and can result in altered genes, novel traits, and new species.
How did the changes in environment affect the finches?
Smaller finches with less-powerful beaks perished. The Grants found that the offspring of the birds that survived the 1977 drought tended to be larger, with bigger beaks. So the adaptation to a changed environment led to a larger-beaked finch population in the following generation.
How did the finch population change?
How did the finch population change from before the drought to after? According to Figure 1, the average beak depth increased in size and the finch population had more finches with greater beak depths in 1978 than before the drought.