Darwin’s finches have different beaks in terms of size and shape to be able to eat different food sources like insects, nectar, and seeds. Cactus finches have longer, more pointed beaks to probe cactus flowers compared to their relatives, the ground finches. If a plant disease killed a large portion of the cacti on the Galapagos islands, what would the future populations of finches look like in terms of beak size and shape? Use your knowledge of natural selection to determine which option is most likely.(2 points)

Question

Responses

Ground finches would survive and pass on their beaks, but they would mate with the remaining cactus finches, creating a new hybrid that is somewhere between short versus long and narrow versus wide.
Ground finches would survive and pass on their beaks, but they would mate with the remaining cactus finches, creating a new hybrid that is somewhere between short versus long and narrow versus wide.

Cactus finches would compete for food with ground finches and exhib…

Answer 1

Ground finches would have a survival advantage as they are able to eat a wider variety of food sources compared to the specialized cactus finches. Over time, the cactus finches would face difficulties in finding enough food to survive and reproduce. As a result, the population of cactus finches would decrease while the population of ground finches would increase.

In terms of beak size and shape, the future populations of finches would likely have smaller, more generalized beaks that are able to eat a variety of food sources including seeds and insects, similar to the ground finches. The specialized long and pointed beaks of the cactus finches would be less advantageous in the absence of their main food source, the cactus flowers. Natural selection would favor those individuals with beaks that are better adapted to the available food sources, leading to a shift in the characteristics of the finch populations.