In the study of evolutionary biology, it is accepted that evolution occurs as a result of species developing new traits that enable them to outlive their peers. If, for example, a hare is able to run faster than its fellow leporids, then that particular hare will be able to avoid predators, and be more likely to spread its genetic material. Similarly, if a creature is born with a fur colour that better camouflages it from a predator's eyes, it too will have an evolutionary advantage. These two examples illustrate the two types of traits: acquired traits, which are developed as a result of a creature's actions, and inherited traits, which a creature has no control over.
Acquired traits can consist of many different qualities. Level of fitness, possessions, social cliques and geographical location could all be considered acquired traits of people. We choose to express ourselves in certain ways, and that leads to the development of traits that correspond to that self-expression. In animals, which do not have the luxury of our level of freedom and choice, acquired traits may include position in a pack or scars from old wounds. Any characteristic of a creature that is a result of that creature's life, and not of its ancestors, is an acquired trait.
Inherited traits are traits that are a part of a creature's genetic structure. For example, hair and eye colour are qualities that we are born with, and they depend on the genetic code of our parents and grandparents. Skin colour, height and predisposition to some diseases are also inherited traits.
Traits with Both Factors
Many characteristic traits are too broad to be defined exclusively as inherited or acquired. Consider, for example, wealth. Obviously, everybody has the potential to achieve wealth, no matter what their natures, but people who are born into wealthy families tend to be exposed to better training and education and are able to spend less time struggling to survive. As a result, these people tend to succeed in the gain of monetary wealth. However, there are countless exceptions; Many wealthy people wind up bankrupt, and many with humble beginnings become wealthy. This is because of the combination of inherited (setting) factors and acquired (effort and willpower) factors.
Evolution and Traits
Evolution occurs when a species has a trait that gives it an advantage over other species. This advantage will directly or indirectly facilitate that species' reproduction. For example, if a predator is born with longer claws or better vision, it will be able to hunt and feed itself and its mate better, live longer and be able to spread its genetic pattern farther. Generally, these advantageous traits are first caused by mutations. Acquired traits may help a single animal, but not its offspring. Inherited traits will help the offspring, but must be inherited from a previous generation. So, the ideal trait must be an inherited trait that a creature is born with, despite it not being part of its genetic pattern. These anomalous traits are caused by mutations during fertilisation.
When evolution was first being considered, there were two primary schools of though as to how it worked. The accepted process is Darwin's theory of natural selection. Natural selection occurs when a member of a species is better able to survive and reproduce. However, the other theory was popular for many decades. This theory was Jean-Baptiste Lamark's theory of acquired characteristics. According to Lamark, acquired traits could be transmitted through reproduction. He believed that as an animal developed some trait, then their offspring would be predisposed to that same trait. We now know this theory to be false, but is presents an interesting insight into the pondering of our forefathers.