February 12, 2009

natural selection

There is another birthday being celebrated today around the world.

Happy Birthday Charles Darwin !!!

1 comment:

  1. Happy Birthday Mr Darwin!!

    According to you attached article it states that Darwin was the first to introduce the idea of an evolutionary process. I belive that the idea was around as far back as Aristotle.

    Developments before Darwin's theory
    The idea of biological evolution was around long before Darwin published On The Origin, and was set out in Classical times by the Greek and Roman atomists, notably Lucretius. Some sources have traced the concept back as far as Aristotle.[5] However, Christian thought in Medieval Europe involved complete faith in the ancient Biblical teachings of creation according to Genesis. Its concepts including "Created kinds" were interpreted by the priesthood as theology, then the Protestant Reformation widened access to the Bible and brought more literal interpretations. Natural philosophers exploring the wonders of what they saw as God's works in nature made many discoveries, and naturalists such as Carolus Linnaeus categorised an enormous number of species. A new belief developed that the original pair of every species had been brought into existence by God not so long ago. By the time of Darwin's birth in 1809, it was widely believed in England that both the natural world and the hierarchical social order were held stable, fixed by God's will, with nothing happening purely naturally and spontaneously.[6]

    The idea that fossils were the remains of extinct species was first put forward by Robert Hooke in the mid seventeenth century, and the paleontological work of Georges Cuvier established the reality of extinction conclusively in the 1790s.[7] Several competing theories of geology were put forward, notably James Hutton's uniformitarian theory of 1785, which was expanded by Charles Lyell and explained in his influential Principles of Geology in the 1830s, that envisioned gradual change over aeons of time. Some individuals put forward evolutionary concepts. In the 18th century Georges-Louis Leclerc, Comte de Buffon suggested that species might change, within limits, over time and that some similar animal species (for example lions, tigers, pumas and house cats) might be related by common descent.[8] By the end of the 18th century Charles Darwin's grandfather Erasmus Darwin had proposed more general ideas of common descent with all warm blooded creatures sharing a common ancestor and with organisms "acquiring new parts" in response to stimuli then passing these changes to their offspring.[9][5] In 1809 Jean-Baptiste Lamarck developed the first fully developed scientific theory of evolution, which he called transmutation of species. Lamarck's theory proposed two mechanisms driving evolution. One was an inherent progressive tendency that drove species towards greater complexity. The second, which became known as Lamarckian inheritance, or inheritance of acquired characteristics, was the ability of organisms to inherit changes brought about through increased use or disuse of organs in response to the organism's environment; this mechanism lead to adaptation to local environmental conditions. Lamarck did not propose common descent. Instead his concept was of separate lineages each progressing towards greater complexity in a linear fashion.[5]

    Such ideas were seen in Britain as attacking the social order, already threatened by the aftermath of the American and French Revolutions.[10] In England, natural history was dominated by the universities which trained clergy for the Church of England in William Paley's natural theology which sought evidence of beneficial "design" by a Creator. British naturalists adopted Georges Cuvier's explanation of the fossil record by catastrophism, the concept that animals and plants were periodically annihilated and that their places were taken by new species created ex nihilo (out of nothing), modifying it to support the biblical account of Noah's flood.[11] However Lamarck's ideas were taken up by Radicals who wanted to overturn the establishment and extend the vote to the lower classes.[12]