This is a chart of different Eras and time periods during the planets time period from start to finish and is basically the history of life on earth and shows how organisms started to change from one another as time went by and totally different species of animals ranging from mammals,reptiles,amphibians,aquatic ,etc.
As time goes by a certain species or organisms can goes through a change caused by the environment,food supply,geographical landscape,etc For instance a giraffe only food source comes from the leaves of trees(example shown to the right)Since its need those leaves as a source of food its need to find a way or have a way to reach it.As time goes by it starts to adapt to its common food source and as a result it gets a longer neck in order to make it easy to reach its food source.
As this time goes by every other organism and species will have a special adaptation or quality of its own. There's certain evidence of this change through the fossil record and fossil specimens found throughout the world.Penguins have shown to have these changes and diversity within their species and undergo having different traits from one another into different kinds of penguins.