Natural Selection

and the evolution of the Galapagos Tortoises

What is Natural selection, exactly?

Natural selection is defined as;

"the process in which organisms better adapted to their environment tend to survive and produce more offspring."

The theory of natural selection was first fully explained by Charles Darwin, and it is now regarded as being the main process that brings about evolution.

What Is Natural Selection? a Youtube video made by Stated Clearly goes into great detail about natural selection and evolution, as well as Charles Darwin's theories on evolution.



Common Decent is covered between 0:38-0:50 seconds. it is covered again from 1:42-2:05, with the Quote "You cannot get order and complexity from chaos alone..."

the video also covers Charles Darwin's theories between 2:45 and 3:00.

What is Natural Selection?

What is the difference between Evolution and Natural selection?

"most of us hear the word evolution and think of the process by which species change and adapt, and maybe turn into other species or go extinct. But that is just the evolution of life forms by means of natural selection." Evolution itself means the gradual change over a set period of time. Natural selection and evolution go together hand in hand. certain evolutionary traits give some species a distinct advantage over others.

Evolution vs Natural Selection

Natural Selection and the Galapagos Tortoise

Saddleback tortoises are found on the drier islands of the Galapagos with vastly spread plant life that's often hard to reach from the ground.. They have longer necks and legs than their domed pals, they have a shell shape that lets them extend their heads up higher. Over many generations the tortoises with "saddleback"-shaped shells were more successful at getting food from higher bushes and trees than dome-shaped tortoises. The tortoises that ate better were also better able to survive and reproduce.


Dome-Shaped tortoises are much more typical of the rest of the worlds tortoise species. It has no need for extra height as it will normally just push through dense undergrowth trampling and eating the grass. The front end of its shell is closed allowing it to retreat into an almost fully protected casing.

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Different evolutions of Galapagos Tortoise

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Natural selection is the Bee's knees, or would be if bees had evolved with knees - Darwin