Written by Hana Kucera

Evolution is the process of change in the inherited traits of organisms over a number of generations. The key idea behind biological evolution is that all organisms share a common ancestor.

In most cases, evolution occurs as a result of organisms that have traits better suited to their environment producing more offspring. But what is it that causes some organisms to be better able to reproduce than others? Selection. Here’s where the idea of “survival of the fittest” comes in. Selection is the process that leads to organisms that have favourable traits being able to produce more offspring than those with less favourable traits. There are several types of selection including natural selection, sexual selection and artificial selection.

But what about “survival of the fittest?” Would going to the gym give you an evolutionary advantage? We now know that those best suited to their environment will pass on their traits, it is important to remember that only traits that are heritable will be passed on. So just because someone can grow large muscles by going to the gym, and these large muscle may be helpful for survival and reproduction, his/her offspring will not necessarily have large muscles. This is because the capability to gain muscle may be heritable, but the muscles themselves are not.

Since reproduction is one of the keys to evolution, all organisms are connected through a shared ancestry. In the same way that you and your cousin have the same grandmother, all organisms shared an ancestor billions of years ago. This sometimes leads to the confusing question: “Did humans come from monkeys?” The answer is: “No, they shared a common ancestor with monkeys.”

Evolution can lead to the formation of new species. The changes in inherited traits over time can build up so much that two populations become different enough to be considered separate species. Organisms are considered separate species once they can no longer reproduce and produce offspring that are also capable of reproduction.  

If you are interested in topics relating to evolution, see the following articles:

    • Natural Selection