Origin of Species

Animals were studied in the ancient world, most famously by Aristotle who classified fauna according to scala naturae – the idea that the natural world could be arranged on a scale like the rungs of the ladder, each organism in its rightful place according to its degree of ‘perfection’.

An Age of Exploration began in the 1400s which brought European scientists into contact with animals around the world. Natural history – the study of living organisms and their environments – became established as a legitimate branch of scientific enquiry. It became accepted practice for expeditions to include naturalists and scientists and the subject of natural science began to be included
in medical schools.

Naturalists noted similarities between different species and developed theories about animal species changing, but the idea of common ancestry developed slowly.

John Hill
A general natural history (1752)

 

John Hill was a British physician, well known for his publications on natural science. He was one of the first naturalists who included microscopic organisms in his book on animals: ‘their size does not exclude them from their rank among animated beings’. Hill had many interests - he was a writer, botanist, apothecary and a failed actor.

His contemporaries accused him of plagiarism – on this page that illustrates mammals it is clear that some of the images have been copied from previous unrealistic images – the bear’s and tiger’s heads are unrecognisable and the lion’s eyes look added on to the otherwise accurate image. Hill named the different species of monkeys after their physical attributes: ‘the long legged ape with no beard, ‘the hairy ear’d ape’ and ‘the long taild brown ape with rounded claws’.

Edward Tyson
Orang-outang sive homo sylvestris (1751)

 

In 1680 English physician Edward Tyson dissected a porpoise and noticed it was more similar to land animals than to other fish. He realised it was not a fish, even though it looked like one. Tyson’s observation was a major contribution to the history of biology at the time when the concept of mammals had not been developed.

In 1698 Tyson dissected a chimpanzee and concluded that it had more similarities with humans than with monkeys. He recognised it as belonging to a new family of apes between monkeys and humans and viewed it as the connecting link between the 'animal' and the 'rational'. Tyson believed humans were also animals, but with unique traits, like intelligence, speech, use of hand and the presence of a rational soul. Tyson’s studies influenced the later ideas of evolution.

Alexander Humboldt
Recueil d’observations de zoologie (1811)

 

Alexander Humboldt was a German scientific explorer and natural philosopher who spent five years travelling around South America, Mexico and Cuba. In 1802 he climbed Chimborazo, in Ecuador, which was then thought to be the world’s highest mountain (6,310 meters high). He carried with him various instruments – telescopes, compasses, barometers, thermometers, rain gauges – to study natural phenomena.

The image shows Chiropotes satanas Humboldt observed in the Orinoco region (Venezuela and Colombia). It is now known by the common name Humboldt bearded saki. Charles Darwin was inspired by Humboldt and described him as ‘the greatest traveller who ever lived’. He wrote in his diary that he repeatedly read Humboldt’s Personal Narrative while on his own travels on the Beagle.

Charles Darwin
On the origin of species by means of natural selection (1859)

 

When he was 16, Charles Darwin enrolled to study medicine at the University of Edinburgh, but soon realised that natural history was his true passion. He joined the crew of the Beagle as a naturalist on a 5-year old journey around the world. Darwin collected plants, animals, rocks and fossils.

Darwin’s theory of natural selection says that any organism is more likely to pass on its genes if it inherits the traits that are best suited for its environment. The driving force is sexual reproduction and the favourable traits are passed on to new generations.

Darwin’s idea created a lot of controversy at the time – but now is accepted as one of the greatest discoveries in the history of science.