Final answer:
Complex human characteristics like adult height and skin color are polygenic traits influenced by multiple genes and environmental factors, leading to a wide range of phenotypes. Eye color variation is a result of non-Mendelian inheritance patterns. The number of phenotypes for these characteristics exists on a spectrum, making it hard to quantify exactly.
Step-by-step explanation:
Complex Characteristics and Polygenic Traits
Complex human characteristics such as adult height and skin color are examples of polygenic traits. These traits do not have a simple inheritance pattern as one might observe with single-gene traits; instead, they involve the action of multiple genes, often in conjunction with environmental factors. For example, while genes play a crucial role in determining adult height, environmental factors such as nutrition can impact its full expression. Similarly, skin color is influenced by genetic factors as well as the level of exposure to ultraviolet radiation.
Eye color is another characteristic that illustrates the complexity of inheritance. The variety of eye colors, including green, blue, brown, black, hazel, violet, and grey, is due to non-Mendelian inheritance patterns, which include phenomena such as codominance, incomplete dominance, and multiple alleles.
Morphological differences such as body symmetry variations, and biochemical differences like mutations in the CCR5 gene, further illustrate the complexity of human traits. The study of biological anthropology reinforces the idea that human traits vary along a spectrum, contributing to the broad diversity seen in populations around the world.
The Number of Phenotypes
Regarding the number of phenotypes each characteristic has, it's difficult to give an exact number because these phenotypes exist on a spectrum due to the involvement of multiple genes and environmental factors. However, the possibility for variation is extensive, resulting in a wide array of observable traits within the human population.