Early Theories of Evolution

  • 350


    He established a famous academy called the Lyceum in Athens. About 30 of his treatises on a variety of philosophical topics remain in existence today. Aristotle was one of the first ever to come up with even a quasi-evolutionary speculation about the nature of living things. He saw that there was a blurred distinction between living and nonliving matter. all things strove toward perfection (the divine), "evolving" through many intermediate forms in the process.
  • 500


    He studied fossils and put forth various theories of evolution of life.
  • 520


    Greek philosopher, of Miletus , wrote a text called " On Nature" in which he introduced an idea of evolution, stating that life started as slime in the oceansa and eventually moved to drier places. He also brought up the idea that species evolved over time.
  • Jan 4, 1581

    James Ussher

    James Ussher
    He was a 17th century Anglican archbishop of Armagh in Northern Ireland. He believed the theory of the "Great Chain of Being." This held that God created an infinite and continuous series of life forms, each one grading into the next, from simplest to most complex, and that all organisms, including humans, were created in their present form relatively recently and that they have remained unchanged since then.
  • John Ray

    John Ray
    The concept of genus and species was actually developed in the late 1600's by Ray, an English naturalist and ordained minister. This was very controversial at the time since it implied that people were part of nature, along with other animals and plants. In addition, it meant that we were biologically closer to the other primates than to all other animals.
  • Carolus Linnaeus

    Carolus Linnaeus
    Linnaeus apparently believed that he was just revealing the unchanging order of life created by God. The goal of documenting change in nature would not have made sense to him. Late in his life, however, he was troubled by the fact that plant hybrids could be created by cross pollination. These were varieties that had not existed before. Linnaeus stopped short of concluding that these plants had evolved. His most important contribution to science was his logical classification system.
  • Immanuel Kant

    Immanuel Kant
    The German philosopher Immanuel Kant developed a concept of descent that is relatively close to modern thinking; he did in a way anticipate Darwinian thinking. Based on similarities between organisms, Kant speculated that they may have come from a single ancestral source.
  • Pierre-Louis Moreau de Maupertuis

    Pierre-Louis Moreau de Maupertuis
    In his book, "Systeme de la Nature' theorized on the nature of heredity and how new species come into being. He thought that speciation took place by chance events in nature, rather than by spontaneous generation as was believed at the time. Has another book, "Essai de Cosmologie".
  • Charles Bonnet

    Charles Bonnet
    Swiss naturalist, wrote his book, "Philosophical Palingesis" that the females of each organism contain the next generation in miniature form. He believed that natural catastrophies sparked evolutionary changes in organisms. His idea of evolution was analogous to organisms climbing a ladder of life with animals becoming intelligent, primates becoming huma, and humans becoming angels.
  • George Louis Leclerc, Comte de Buffon

    George Louis Leclerc, Comte de Buffon
    The French mathematician and naturalist, George Louis Leclerc, Comte de Buffon , actually said that living things do change through time. He speculated that this was somehow a result of influences from the environment or even chance. He believed that the earth must be much older than 6000 years. In 1774, in fact, he speculated that the earth must be at least 75,000 years old. He also suggested that humans and apes are related.
  • Erasmus Darwin

    Erasmus Darwin
    Erasmus was an English country physician, poet, and amateur scientist. He believed that evolution has occurred in living things, including humans, but he only had rather fuzzy ideas about what might be responsible for this change. In this latter work, he also suggested that the earth and life on it must have been evolving for "millions of ages before the commencement of the history of mankind."
  • Alfred Russel Wallace

    Alfred Russel Wallace
    Charles Darwin and Alfred Russel Wallace both independently developed the idea of the mechanism of natural selection (Natural Selection) after reading Thomas Malthus' Essay on the Principle of Population. Wallace was a champion of rather radical social causes and later openly embraced spiritualism - all elements that resulted in the downplay of his role in the discovery of natural selection.
  • Thomas Malthus

    Thomas Malthus
    Thomas Malthus , an English clergyman and pioneer economist, published Essay on the Principles of Population. In it he observed that human populations will double every 25 years unless they are kept in check by limits in food supply. His book said that all plant and animal populations have this same potential to rapidly increase their numbers unless they are constantly kept in check by predators, diseases, and limitations in food, water, and other resources that are essential for survival.
  • Jean-Baptiste Chevalier de Lamarck

    Jean-Baptiste Chevalier de Lamarck
    Believed that microscopic organisms appear spontaneously from inanimate materials and evolve gradually and progressively into more complex forms through a constant striving for perfection. Also that evolution was mostly due to the inheritance of acquired characteristics as creatures adapted to their environments. And that evolution occurs when an organism uses a body part in such a way that it is altered during its lifetime and this change is then inherited by its offspring.
  • George Cuvier

    George Cuvier
    Cuvier advocated the theory of catastrophism , as did most other leading scientists of his day. This held that there have been violent and sudden natural catastrophes such as great floods and the rapid formation of major mountain chains. Plants and animals living in those parts of the world where such events occurred were often killed off according to Cuvier. Then new life forms moved in from other areas.
  • Charles Lyell

    Charles Lyell
    Charles Lyell , concluded that Cuvier's catastrophism theory was wrong. He believed that there primarily have been slower, progressive changes. In his three volume Principles of Geology, Lyell documented the fact that the earth must be very old and that it has been subject to the same sort of natural processes in the past that operate today in shaping the land. These forces include erosion, earthquakes, glacial movements, volcanoes, and even the decomposition of plants and animals.
  • James Hutton

    James Hutton
    Uniformitarianism , had been developed originally by the late 18th century Scottish geologist, James Hutton. This held that the natural forces now changing the shape of the earth's surface have been operating in the past much the same way. In other words, the present is the key to understanding the past.
  • Jacques Boucher Crèvecoeur de Perthes

    Jacques Boucher Crèvecoeur de Perthes
    He was a customs officer in northern France during the early 1800's. His hobby was collecting ancient stone tools from deep down in the Somme River gravel deposits. Since he found these artifacts in association with the bones of extinct animals, he concluded that they must have been made at the time that those animals lived.
  • Thomas Huxley

    Thomas Huxley
    Thomas Huxley was known as "Darwin's Bulldog" because of his passionate, eloquent defense of Darwinism against attackers of the theory. Huxley, born to a poor family, had little education became a medical apprentice and won a scholarship to study at a hospital. He then established his reputation as a scientist through research conducted while serving as assistant surgeon on the H.M.S. Rattlesnake. Though he was once an opponent of evolutionary change, he quickly embraced Darwin's theory.
  • Gregor Mendel

    Gregor Mendel
    Through plant breeding experiments, he discovered that there is a recombination of parental traits in offspring. Sadly, Darwin and most other 19th century biologists never knew of Mendel and his research. It was not until the beginning of the 20th century that Mendel's pioneer research into genetic inheritance was rediscovered. This was long after his death. He never received the public acclaim that was eventually showered on Darwin during his lifetime.