Learn: Variation

Welcome!This lesson is all about variation. We'll explore what it means, why it's important, and how it influences life on Earth. Let's dive in!

What is Variation?Variation refers to the differences between individuals of the same species. These differences can be caused by genetic factors, environmental influences, or a combination of both. Variation is essential for natural selection and evolution.

Types of VariationThere are two main types of variation:Genetic variation – Differences in DNA inherited from parents.Environmental variation – Differences caused by surroundings or lifestyle, such as diet or climate.Some traits, like eye colour, are purely genetic, while others, like weight, can be influenced by both genes and environment.

Continuous and Discontinuous VariationVariation can be categorised as:Continuous variation – Traits that show a range of values, like height or weight.Discontinuous variation – Traits that fall into distinct categories, like blood type or tongue rolling ability.Continuous variation often results from multiple genes and environmental influences, while discontinuous variation is typically controlled by a single gene.

Why is Variation Important?Variation is crucial for the survival of species. It allows individuals to adapt to changing environments and ensures that populations are not wiped out by diseases or threats. For example, some plants may survive a drought due to variation in their genes.

Inherited and Environmental VariationInherited variation comes from genes passed down from parents, while environmental variation is influenced by external factors such as diet or exercise. For instance, a person may inherit traits like hair texture but develop a tan due to sun exposure.

Natural Selection and VariationNatural selection depends on variation within a species. Individuals with advantageous traits are more likely to survive and reproduce. Over time, these traits become more common in the population, driving evolution.

Review Time!Excellent work! You've learned about variation, its types, causes, and importance. Let's test your understanding with a few questions.