Lamarck’s Inheritance of Acquired Traits Evolution begins with evidence from fossils and the idea that species gradually change over time. Lamarck proposed that organisms adapt to their environment by developing characteristics that are later inherited by their offspring. He detailed theories such as need-driven change and use-and-misuse, exemplified by giraffes developing longer necks to reach food, a concept now largely replaced by genetic understandings.
Darwin’s Natural Selection Observations from the Galapagos Islands led to the development of natural selection as a mechanism for evolution. Darwin explained that species produce more offspring than can survive, resulting in competition where only the best-adapted individuals pass on their traits. His theory stresses that random variations, rather than directed changes, determine which traits are perpetuated, with artificial selection reinforcing this natural process.
Comparing Evolutionary Mechanisms and Modern Insights The discussion contrasts Lamarck’s idea of directed adaptation with Darwin’s emphasis on random variation and natural selection. Both theories concur that species evolve over generations, although they differ on how adaptations are acquired and passed on. Interactive questions highlight that genetic mutations and changing environments ensure that evolution continues, while environmental shifts can lead to species extinction.