What is natural selection An important question Why do the animals plants and people on our planet look and act the way they do And why are there so many different types or species of living things These are among the most important questions in science especially biology the science of life For most scientists the answer is natural selection Discovering the world The theory of natural selection developed in the 1800s This was a time when scientists and explorers were finding out more and more about the natural world and its plants animals and other creatures such as fungi and bacteria From fossils they also learned about the creatures that lived on the earth a long time ago They wondered why some of these such as dinosaurs were so different from modern life-forms Had living things been changing or evolving all this time And if they had how Finding an answer Several scientists came up with interesting ideas but the most famous of them all was Charles Darwin and the This artwork shows the giant Megalodon shark the biggest fish ever The shark lived between 25 and 1 6 million years ago and fossils show it was 66 feet 20 m long A modern white shark also shown measures around 20 feet 6 m
The camel has evolved to become adapted to desert life and can survive for many days without food or water It can also withstand the extreme temperatures in the desert and its wide feet help it walk on soft sand theory he named natural selection Today Darwin’s work is seen as one of the most important scientific discoveries ever made However not everyone agrees with everything Darwin said and his theory still causes arguments I have called this principle by which each slight variation if useful is preserved by the term of Natural Selection Charles Darwin from On the Origin of Species published 1859 How natural selection works So what is this theory It will be explained again later but here is a simple version In any species some individuals will be better at surviving than others For example some rabbits can run faster than others and are better at escaping from predators Those that survive longest will be more likely to have plenty of young They pass on their qualities such as big strong back legs to their young In this way nature selects the most useful qualities in a species Over a long time as this happens over and over again the species changes or evolves What is evolution Evolution is a word that means gradual change in a series of stages By the 1800s most scientists agreed that living things must have evolved over time Natural selection is not the same thing as evolution but it is a way of explaining how evolution happens 7
