Individuals in a population are not exactly the same.

Each individual has a unique set of traits, such as size, color, height, body weight, skin color, and even the ability to find food.

Sometimes, offspring of the same parents still differ a lot among themselves. You can find that among the 3 sisters, one may be very tall, the other may have dark hair and the third may have a rounded nose tip. Such differences in individuals from the same parents are called variations.

Characteristics or traits that are inherited are determined by genetic information. Some other traits like dialect or accent, scars, skin texture, or even bodyweight may be determined by some external

or environmental factors.

These factors include

• Diet
• Climate
• Culture
• Lifestyle
• Language
• Accidents

Sometimes a person may not have inherited a trait, but some conditions have modified the individual to exhibit specific traits. If a child with brown eyes acquires a disease that affects his eyes and turns them yellow, that may be a diseased induced variation.

In the same vein, a child may have the tendency to be tall, but diseases and poor diet during his early years may cause him to have stunted growth.