Darwin, Wallace & Lamarck

• Who proposed the theory of evolution by natural selection

  Darwin and Wallace independently
• Lamarck‘s theory of evolution

  Suggested that organisms could acquire traits during their lifetime and pass these traits to their offspring
• Why was Lamarck’s theory considered incorrect

  His theory was disproven because acquired characteristics do not alter an organisms DNA
• What key observation did Darwin make about species

  Observed that individual organisms within a species show a wide range of variation for specific traits
• How did Darwin explain the diversity of species

  Proposed that species gradually develop over time through natural selection where those best adapted to their environment survive and reproduce
• Main difference between Lamarck’s and Darwin’s theories

  Lamarck’s theory involved inheritance of acquired traits while Darwin’s theory involved natural selection of existing variation
• Why did some people initially reject Darwin and Wallace’s theory

  Religious conflict

  Lack of evidence

  Unknown mechanism of inheritance
• How do giraffes’ long neck exemplify natural selection

  Giraffes with longer necks could reach more food and had a survival advantage leading to their traits being passed on over generations