When Darwin first went on board the Beagle, he had an orthodox view of life on earth. He did not go looking for evidence to support evolution. He started the journey with the firm belief that species were fixed entities. But Darwin had an open and inquisitive mind, he was able to make clear observations and interpret them in an unbiased and evidence-based manner.
Darwin made three key observations that made him cast his doubts on the view that species were fixed:
i. The continuity of species through history.
Darwin found fossils from some extinct armadillos in southern America. The skeletons were much larger in size than those of the existing ones; however, much of the construction was similar. Intrigued by this, Darwin realised that the armadillo species must have changed over time.
ii. The geological specificity of species.
When Darwin was travelling across the great grasslands in southern America, he noticed that different regions along the geological landscape were occupied by similar species of ostrich with certain small differences. He thought of the possibility of species differentiating and developing according to geological differences.
iii. Evidence from the Archipelagos.
Darwin compared the species found on the Archipelago of Cape Verde with those found on Galapagos. While the two Archipelagos were similar in terms of environment and geological landscape, the respective wildlife were drastically different. From a creationist’s point of view this seemed strange: if two environments were similar then God should have created similar species to put into them. Darwin speculated that species on the Archipelago of Cape Verde came from the near-by African continent, but this was not the case for the wildlife on the distant Galapagos Islands, thus accounting for the observed phenomenon.