Evolution and Species Adaptation

Evolution

• Evolution is the change in life on Earth over long periods, with living things adapting to environmental changes.
• Charles Darwin is known as the "Father of Evolution," proposing that all living organisms share a common ancestor.
• Darwin's theory of evolution is based on descent from a common ancestor, and that all organisms are related.

Species

• A species is a group of similar organisms that interbreed to produce fertile offspring.
• Darwin's observations of species, particularly finches in the Galapagos Islands, showed differences in beak type related to available food sources, indicating adaptation to different environments.
• Finches with different beak types were well-suited to specific food sources on their respective islands.
• This process of adaptation over long periods may have led to the formation of new species.

Darwin's Observations

• Darwin's observations of species were primarily based on global travels during the HMS Beagle expedition (1831-1836).
• He studied various organisms and their adaptations in different environments.
• His observations included the distribution and characteristics of organisms in South America, Australia, and the southern tip of Africa.

Descent with Modification

• Darwin proposed that new species arise from pre-existing species through gradual changes over time.
• He believed that species share a common ancestor and accumulate heritable genetic differences.
• "Descent with modification" refers to the process where traits are passed down through generations, accumulating differences leading to new species.