Variation

• Differences within a species are called variation.
• The appearance of an organisms is called its phenotype
• Genetic variation: this is a result of the genetic material that you inherit from your parent. this includes eye color, blood group and the presence of any genetic disorders
• Environmental variation: this is as a result of the impact of the environment around you. Examples include scars, tattoos and piercings
• Most characteristic are affected by both environmental and genetic variation. For example, your height is mostly determined by your genes. however, if your diet is very poor you may not grow to your full potential height.
• The variation of a characteristic displayed within a species can be divided into two groups. these are discontinuous and continuous.
• Continuous variation is a gradual change in a characteristic across a population. For example, human height is a continuous variation because a person's height can be any value between the shortest and tallest person in the world. Other examples of continuous variation include weight, foot length, and mass
• Continuous variation is represented graphically as a histogram, which shows a normal distribution with most individuals around the average value.

  
• Discontinous variation is where there are distinct differences or gaps between different values of a characteristic. This means that an individual will either have one form of the trait or another. An example of discontinuous variation is whether someone has blue eyes or brown eyes. There is no intermediate state between having blue eyes and having brown eyes.
• Discontinuous variation is represented graphically using bar charts, which show discrete categories rather than a range of possible values.