On today's date, 12. February 1809., Charles Darwin was born. Charles Darwin has put the world at the great debt with his contributions to science and understanding of our natural world.
Darwin formulated the scientific theory of evolution which he published in his book “On the origin of species” (now available for free in digital form).
[please check if it's also in the Public Domain in your country.]
Simply put, evolution means process of change, or adaptation if you will in all life forms over countless generations.
The theory of evolution gives us the scientific explanation as to how did all the amazing variety of species come about. It is the explanation for the complexity of apparent design of life. It is a huge scientific accomplishment for humanity to be able to explain the Origin of species and regard that explanation as a simple fact of life.
As Richard Dawkins would say, Darwin with his brilliant theory showed us that no scientific problem is unsolvable. He showed us that even the very problem of the huge variety of species in the world can be solved without the need for supernatural or magic.
In short, Charles Darwin is a person we cannot thank enough and we cannot honour enough.