Theory of Evolution

1835. The Galapagos Islands. Young English naturalist Charles Darwin collects animal and plant specimens for study. His observations on these islands will be fundamental in formulating his theories which many years later will be published in his great work On the Origin of Species, a revolutionary book that change the way biology was understood, giving rise to new scientific theories. In this book Darwin lay down the scientific principle that each species had not always been the way we know it today. Rather, each one had changed and altered over time. Three concepts are important for understanding Charles Darwin’s theories – natural selection, evolution and the origin of species. In animals and plants,  random trait mutations and modifications can appear. For example, a moth that is born a different color than its parents. Imagine that this mutation or new trait improves an animal’s ability to survive in its environment. Animals with this favorable trait would be better adapted to where they live and have a better chance to feed themselves and to reproduce than other animals of the same species without that trait. The offspring of parents with favorable characteristics will normally inherit those same characteristics. So generation after generation a trait that was rare occurs more frequently, becoming the norm within the species. This process is called natural selection. With the passing of time, these favorable mutations accumulate and species change, constantly adapting to environments that never stops changing. Here’s how the evolution of species takes place. Two groups of animals of the same species that adapt to two different environments over time can come to constitute different species. This way a process as simple as natural selection helps us to understand the Origin of Species.

Charles Darwin was one of the most important men of his era and many consider him among the most influential scientists in history. His theories on the origin and evolution of species were very new for his time and are still studied and discussed to this day. Darwin died in 1882. His legacy changed the thinking of an era and opened the door to a new way of understanding science, the world and the role humans play on this planet.