Final answer:
Ancient ears of corn showed great variation, with small, hard-covered fruits that were selectively bred for larger ears and kernels by early farmers. Color variations were due to anthocyanin pigments leading to a diverse range of kernel colors.
Step-by-step explanation:
The ancient ears of corn, which have been under cultivation and subject to selective breeding for roughly 9000 years, exhibited significant variations compared to modern corn. Ancestral corn, or teosinte, has small ears with fruits encapsulated in hard cases, making them less accessible and thus less desirable for early cultivation.
Through a process of selective breeding, early farmers manipulated these ancestral varieties to develop corn with larger ears and more easily accessible seeds. This was achieved by selecting for favorable traits such as larger ear size and kernels that were not as tightly enclosed. Consequently, modern versions of corn that we see today, which appeared less than 2000 years ago, are the result of these early selective breeding efforts.
The color variations in corn kernels are due to the differential expression of anthocyanin pigments by the cells in the aleurone tissue. The array of colors ranges from colorless (white or yellow where anthocyanins are absent) to rich hues of brown, purple, and even spotted or streaked patterns, offering a vivid illustration of the genetic diversity selected by ancient farmers.