UNRAVELING THE MYSTERIES OF NATURAL SELECTION: NATURE'S INGENIOUS METHOD OF EVOLUTION

We have claimed that, operating on the raw material of variation presented to it, natural selection has directed evolution on a large scale, over millions of years, producing the diversity of life we now see in the world. That claim is rooted in the meaning of natural selection; in short, it’s the theory of evolution. Let’s begin by defining natural selection and unpack what we mean by it.

DISCOVERING THE CORE OF NATURAL SELECTION

At its heart, then, natural selection is the process in which, among organisms that happen to occupy the same environment, it is the better-suited organisms who live the longest and, subsequently, reproduce most with each other, thus bequeathing their advantages to their descendants. In short, the principle of natural selection is the principle of the ‘survival of the fittest’, with ‘the fittest’ in question being organisms that, by virtue of their special kinds of constitution, are better than others at occupying their environment.

TRACING BACK TO THE ORIGIN OF NATURAL SELECTION

Informed by the keen observations of the mid-19th-century naturalist Charles Darwin and his book On the Origin of Species (1859), the theory of natural selection has come to underlie our entire understanding of natural history. Natural selection, Darwin argued, was an evolutionary process by which many species came into being: ‘organisms vary… [and] environmental pressures would predispose certain traits to be favoured over others, slowly ‘propelling’ the evolutionary process forward.

ILLUSTRATING NATURAL SELECTION THROUGH REAL-WORLD EXAMPLES

The Story of Peppered Moths

The classic case of natural selection in action, at least according to textbooks, is the example you probably learned about in middle school: the peppered moth. Before the Industrial Revolution, the native moth population was mostly white, because it blended in with light barked trees. As time went on, pollution from industry coated the trees in soot, and darker moths gradually took over, illustrating the role of natural selection in turning the peppered moth population dark.

Antibiotic Resistance: A Modern Challenge

Another terrifying example of natural selection is antibiotic resistance: by using antibiotics to treat bacteria, we’ve given those strains of bacteria that can survive the antibiotic a boost. Antibiotic resistance is responsible for many illnesses and hundreds of thousands of deaths every year across the globe.

Polar Bears: Adaptation to the Arctic

Natural selection has been perfectly happy to make these evolutionary hops and leaps. From a genomic standpoint, polar bears today are fully evolved from their brown bear ancestors. Their white coats and the size of their fat pads are not a work in progress, nor are the hunting strategies that polar bears developed for their arctic homes.

THE SIGNIFICANCE OF NATURAL SELECTION IN MODERN SCIENCE

Today, the biological significance and the practical impact of natural selection are clearly understood. Natural selection is the foundation of medical and agricultural research, and it helps us understand how species are able to survive in a changing environment. This insight is crucial for efforts to preserve biodiversity and manage ecosystem resources in the future.

EMBRACING THE NATURAL SELECTION PARADIGM: OUR PLACE IN NATURE

Knowing about natural selection helps us better appreciate the beauty of the natural world, and see how we’re linked to the endless variety of life on this earth. It should encourage us to reflect on how we can best protect the equilibrium of ecosystems.

EXPLORING THE ORIGIN OF NATURAL SELECTION

Taking a step back to consider the origin of natural selection shows why it is so central to biology as a whole. It is the foundation of evolutionary biology: evolution is not a simple process of animals changing from one form to another, but a dynamic and interconnected system. It was the work of biologists such as Charles Darwin, who first described it, that explains why evolution is such a vibrant part of the natural world, and has changed our view of our own place in it.

From its historical discovery to its role in modern science, natural selection displays the creative power of nature to generate constant change and diversity. By uncovering the details of this key concept, we can learn how life has been shaped by evolution, and gain an improved perspective on why biodiversity is the heritage of every person, and why it should be conserved. In understanding these Darwinian processes more fully, we come to appreciate more fully the beauty and power of the natural ways in which our world works.