After the drought of 1977, researchers hypothesized that on the Galápagos island Daphne Major, medium ground finches with large,
deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus cistoides fruits. A tourist company sets up reliable feeding stations with a variety of bird seeds (different types and sizes) so that tourists can get a better look at the finches. Which of these events is now most likely to occur to finch beaks on this island? A) evolution of yet larger, deeper beaks over time, until all birds have relatively large, deep beaks
B) evolution of smaller, pointier beaks over time, until all birds have relatively small, pointy beaks
C) increased variation in beak size and shape over time
D) no change in beak size and shape over time
Evolution may be defined as the change in the characteristics of a species over several generation with time. Natural selection acts as a main drivinf force for the evolution.
The drought of 1977 is responsible for the species evolution. The species is larger in this case (as mentioned in the question) and the species has deeper beaks over time. The birds have relatively large and deep beaks because they can easily crack the food.
porque una persona con dos alelos normales presentará un fenotipo normal, mientras que si las dos copias del gen son el alelo mutado que producen una enfermedad, el fenotipo expresará los síntomas característicos de esa enfermedad.
