Lesson 1: Darwin and his ideas Flashcards
Darwin
In 1831, Charles Darwin, at 22, boarded the HMS Beagle, a British survey ship, and departed England. Although Darwin is commonly identified with evolution, he was not the first or only scientist to suggest that organisms evolve over time.
Greek philosophers thought that life evolved gradually.
Darwin’s Voyage
The Beagle’s mission was to explore the coast of South Africa. As the naturalist on board, Darwin had plenty of time to study the various locations. He noticed differences in the vegetation and wildlife compared to prior observations. Temperate South American species were shown to be more suited to tropical settings than temperate Europe. He observed that regions with similar weather had distinct vegetation and fauna. This prompted Darwin to question why, if all species evolved in a single act of creation, there was such a distinct grouping of similar creatures in different parts of the world.
The Galapagos Islands pt 1: What Darwin noticed in the islands
–> A collection of about 20 tiny volcanic islands in the Pacific Ocean.
-This 5-week break was crucial in developing Darwin’s thoughts about evolution. The islands have few animal species and are similar to those found around the South Americancoastline.
The Galapagos Islands pt 2: what are the significant animals who contributed to Darwin?
Darwin relied heavily on finches and giant tortoises in his studies. Although, during his time in the Galapagos, Darwin collected several specimens for further examination, including them,despite his lack of interest in them.
Darwin’s Ideas- 1. Natural Selection
Genetic variety within a species is a natural occurrence.
Adapted variants are more likely to reproduce and pass along their genes to future generations. The following generation will have more of the “fit”alleles.
Darwin’s ideas- 2. Common Descent
Species evolved over time to form organisms.All living forms share a common ancestry, as each species evolved from a pre-existing species.
