Darwin and His Theory Darwin was born in 1809 as the son of a physician. He earlier planned to become a 【1】______ in the Chur

Darwin and His Theory
   Good morning, everyone. Today we will discuss something about Charles Darwin’s life and his famous theory of evolu tion.
   Charles Darwin was born in 1809 in Shrewsbury, England. His father, Robert Darwin, was a physician, and Charles’s mother died when he was eight years old.
   At age sixteen, Darwin left Shrewsbury to study medicine at Edinburgh University. Repelled by the sight of surgery performed without anesthesia, he eventually went to Cambridge University to prepare to become a clergyman in the Church of England. After receiving his degree, Darwin accepted an invitation to serve as an unpaid naturalist on the H. M. S. Beagle, which departed on a five-year scientific expedition to the Pacific coast of South America on31 December, 1831.
   Darwin’s research resulting from this voyage formed the basis of his famous book, On the Origin of Species by Means of Natural Selection. Published in 1859, the work aroused a storm of controversy. Here Darwin outlined his theory of evolution, challenging the contemporary beliefs about the creation of life on earth.
   Darwin continued to write and publish his works on biology throughout his life. He lived with his wife and children at their home in the village of Downe, fifteen miles from London. He suffered from panic disorder, as well as from a disease contracted during his travels in South America in the rest of his life. He died on 19 April, 1882, and lies buried in West minster Abbey.
   Darwin’s Theory of Evolution is the widely held notion that all life is related and has descended from a common ancestor: the birds and the bananas, the fishes and the flowers -- all related. Darwin’s general theory presumes the development of life from non-life and stresses a purely naturalistic "descent with modification". That is, complex creatures evolve from more simplistic ancestors naturally over time. In a nutshell, as random genetic mutations occur within an organism’s genetic code, the beneficial mutations are preserved because they aid survival -- a process known as "natural selection." These beneficial mutations are passed on to the next generation. Over time, beneficial mutations accumulate and the result is an entirely different organism, not just a variation of the original, but an entirely different creature.
   While Darwin’s Theory of Evolution is a relatively young archetype, the evolutionary worldview itself is an old as antiquity. Ancient Greek philosophers such as Anaximander assumed the development of life from non-life and the evolutionary descent of man from animal. Charles Darwin simply brought something new to the old philosophy -- a plausible mechanism called "natural selection."
   Natural selection acts to preserve and accumulate minor advantageous genetic mutations. Suppose a member of a species developed a functional advantage, for example, it grew wings and learned to fly. Its offspring would inherit that advantage and pass it on to their offspring. The inferior or disadvantaged members of the same species would gradually die out, leaving only the superior or advantaged members of the species. Natural selection is the preservation of a functional advantage that enables a species to compete better in the wild. Natural selection is the naturalistic equivalent to domestic breeding. Over the centuries, human breeders have produced dramatic changes in domestic animal populations by selecting individuals to breed. Breeders eliminate undesirable traits gradually over time. Similarly, natural selection eliminates inferior species gradually over time.
   Darwin’s Theory of Evolution is a slow gradual process. Darwin wrote, "Natural selection acts only by taking advantage of slight successive variations; she can never take a great and sudden leap, but must advance by short and sure, though slow steps." Thus, Darwin conceded that, "ff it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down." Such a complex organ would be known as an "irreducibly complex system". An irreducibly complex system is one composed of multiple parts, all of which arc necessary for the system to function. If even one part is missing, the entire sys tem will fail to function. Every individual part is integral. Thus, such a system could not have evolved slowly, piece by piece. Tile common mousetrap is an everyday non-biological example of irreducible complexity. It is composed of five basic parts: a catch ( to hold the bait), a powerful spring, a thin rod called "the hammer," a holding bar to secure the hammer in place, and a platform to mount the trap. If any one of these parts is missing, the mechanism will not work. Each individual part is integral. The mousetrap is irreducibly complex.
   And we don’t need a microscope to observe irreducible complexity. The eye, the ear and the heart are all examples of irreducible complexity, though they were not recognized as such in Darwin’s day.
   Darwin’s Theory of Evolution is a theory in light of the tremendous advances we’ ve made in molecular biology, bio chemistry and genetics over the past fifty years. We now know that there are in fact tens of thousands of irreducibly complex systems on the cellular level~ Specified complexity pervades the microscopic biological world...