Human evolution

Theory of Evolution

  • Period: to

    Beginning of Evolution

    Plato and Aristotle believed that all life existed ion a perfect and unchanging world. This was the accepted theory by society. Life forms were organized into a hierarchy wth man occupying the highest level, beneath God. It was the church that provided explanations for the biologically diversity within organsisms.
  • Georges-Louis Leclerc, Comte de Buffon

    Georges-Louis Leclerc, Comte de Buffon
    He was one of the first scientists to publicly challenge the idea that life forms are unchanging. Buffon believed that there was a common ancestor between humans and apes. His theory suggested that the world is older than 6000 years old. His believe goes against the contemporary understanding of evolution proven.
  • Thomas Malthus

    Thomas Malthus
    In his essay, Malthus proposed that populations produced more offspring than their environments cansupport, and were eventually reduced by starvation and disease. This conclusions supports the idea of evolution by natural selection. Only individuals with the right characteristics to survive in their environment would live through the selective pressure.
  • Georges Cuvier

    Georges Cuvier
    Cuvier was a paleantologist that came to the observation that each strata of rock is charachterized by unique fossil types. It was said that in the deeper stratum, older and more dissilimilar species appeared , in regards to his present day species, Cuvier came to the conclusion that species can emerge and dissapear, and that these occurences must have been from catastrophic events. Such revolutions killed numerous amounts of species, thus providing a reason for the species not existing then.
  • Charles Lyell

     Charles Lyell
    Lyell was a geologist that suggested geological proccesses operate at the same rates in the past as they did then. He predicted that if changes are slow and gradual than the Earth must be older than 6000 years old. This erupted the theory that slow and subtle changes also occur in populations, thus proving that species have evolved over time and continue to evolve.
  • Jean-Babtiste Lamarck

    Jean-Babtiste Lamarck
    He believed that species increased in complexity over time, until they reached a level of perfection. Lamarck had a theory called the "Inheritence of Aquired Characteristics," in this theory he provided a hypothesis for passing hereditary charachteristics from one generation to the next. Adaptations from the environment were believed to be passed on to future generations. He knew that traits were passed on through generations, just not inherited characteristics.
  • Charles Darwin

    Charles Darwin
    On the HMS Beagle, Charles Darwin surveyed the Galapagos Island and observed various organsims living there.His voyage allowed him to observe finches that closely resembled others that he observed on the West coast of South America. This related to his theory that when the environment exerts selective pressure on a species, it adapts to survive, and those without the characteristics suitable, will no be pass on their traits.
  • Charles Darwin

    Charles Darwin
    Darwin concluded that individuals with physical, behavioral, and other traits helped them to survive in their environment, which allowed them to pass on traits to their offsprings.Due to his lengthy research that supported this theory, it became aware that competition for limited resources among individuals of the same species would select for individuals with favourable traits., Charles Darwin
    co-discovered natural selection along side Alfred Wallace.
  • Alfred Russel Wallace

    Alfred Russel Wallace
    Wallace spent time conducting research in the Malay Archipelago, devoloping a theory of evolution. He came to the conclusion that organisms must adapt to their conditions and that only the fittest will survive. Wallace had made the same theory as Charles Darwin and is acknowledged as the co-discoverer on natural selection.
  • Charles Darwin

    Charles Darwin
    Darwin published a book ' Origin of species." In this book, he proposed two main ideas regarding evolution by means of natural selection. Present forms of life have arisen by descent and modification from an ancesral species. The mechanism for modification is natural selection working for long periods of time. These main ideas have risen from his theory of evolution, that Wallace helped contribute to during the same time frame.