The answer is letter b. adaptation. Adaptation occurs when living organisms adapt to their surroundings or environment over a long period of time. In this case, Dark Furred Squirrels were abundant, since squirrels adapted to the dark shady area they have lived and adapted into a dark furred one, which allowed it to be more common due to adaptation.
Answer
Lamarckism, a theory of evolution based on the principle that physical changes in organisms during their lifetime—such as greater development of an organ or a part through increased use—could be transmitted to their offspring.
Lamarck believed that the stretching elongated the giraffe's neck, which became a useful characteristic and was passed onto future generations. This resulted in the length of the giraffe's neck increasing over time. It is now commonly accepted that Lamarck's ideas were wrong.
I believe it is gel electrophoresis.
Gel electrophoresis is a techniwue used to separate DNA fragments or other macromolecules such as RNA and proteins based on their size and charge. It can also determine the actual size of a piece of DNA by examining it next to a standard "yardstick" made up of DNA fragments of known sizes.
A mutation is a change in a DNA sequence. Mutations can result from DNA copying mistakes made during cell division, exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses. Germ line mutations occur in the eggs and sperm and can be passed on to offspring, while somatic mutations occur in body cells and are not passed on.
Recessive mutations inactivate the affected gene and lead to a loss of function. For instance, recessive mutations may remove part of or all the gene from the chromosome, disrupt expression of the gene, or alter the structure of the encoded protein, thereby altering its function.