Discover the biological pathways through time that led to the plants and animals of today
For around 3.7 billion years, life has followed a roadmap of evolution. The journey to modernday life and the more than 2.16 million known species that reside on Earth has been guided by several different evolutionary pathways. The naturalist known as ‘the father of evolution’, Charles Darwin, first proposed the theory of evolution by natural selection after he jumped aboard the HMS Beagle in 1831 and sailed around the world for five years. On his travels, he discovered diverse wildlife, observing that they had anatomy specially adapted to their environments. He concluded that a species’ survival depends on traits that suit its environment. This survival-of-the-fittest approach means that only animals with beneficial characteristics can continue to reproduce and pass them onto their offspring. Darwin proposed that through forces of evolution, an ancestral family tree formed below modern-day species, leading to a common ancestor at its roots.
Forces of evolution are varied and specific to an ecology niche. For many, evolution is driven by sexual selection, whereby qualities in potential mates – such as plumage vibrancy or big antlers – are chosen by a partner to successfully reproduce. For others, natural selection occurs when an aspect of a species’ environment is altered, such as by climatic change, and they are forced to adapt or die. Those that can change go on to reproduce, leading to some anatomical and behavioural differences over millennia, creating new species along the way. Today scientists refer to the creation of a new species as divergent evolution, where a new species separates from a common ancestor. Building on the work of Darwin, the term ‘divergent evolution’ was first introduced by evolutionist John Thomas Gulick in 1890. As the name suggests, divergent evolution occurs when a subgroup within a species diverges anatomically from the rest of the species, with these genes spreading until a new distinct species emerges. All life on Earth has undergone divergent evolution from a distant common ancestor, branching off into new families that form the tree of life.
Did you know? The first reptiles evolved around 315 million years ago
For example, humans share more than 97 per cent of their DNA with the other great ape species on Earth: orangutans, gorillas and chimpanzees. Evolving from a common ancestor more than 25 million years ago, the great apes have diverged from their common lineage to produce an unknown number of now-extinct species that have paved the way for modern-day animals. Althou
