During the first half of the nineteenth century, biologists had come to understand that animal species had changed through time, a process that offered archaeologists interesting parallels for the changes they could observe in human technology and society. The concept was given an enormous public boost by the publication of Charles Darwin’s On the Origin of Species in 1859.
The concept of evolution
During the late eighteenth and early nineteenth centuries, biologists had started to classify the natural world, grouping plants and animals in species, genera, phyla, orders and so on. Their classificatory schemes were based on similarities and differences. Naturalists were beginning to speculate that closely similar species must be closely related and that the differences between them had arisen over time, much as farmers and animal breeders can change the characteristics of their livestock. By the middle of the century, most educated people recognised that numerous animal and plant species were somehow related to each other and that fossils showed that species had changed through time. The concept of evolution was already part of the world view of many people, but there was no explanation for how these changes might have occurred.
Then, Charles Darwin (1809-1882) was persuaded to publish his hypothesis about natural selection in On the Origin of Species by means of Natural Selection in 1859 (although it was another twelve years before he felt confident enough to include humanity in his hypothesis). His principal contribution was to suggest a mechanism that would account for biological change over time: those members of a population best adapted to their surroundings would have a reproductive advantage over others and would thus increase in numbers at the expense of those others. In time, small changes in the characteristics of these living things would change the population from one species to another.
Just as biologists were trying to classify the natural world, archaeologists also began to develop classificatory schemes (such as Thomsen’s Museum-Ordning). Like the biologists, archaeologists classified artefacts according to their similarities and differences, leading to the development of the technique of typology, a means of classifying artefacts and placing them in a developmental sequence. The increasing emphasis on understanding artefactual style and how it had changed through time paralleled the evolutionary theory being applied to the natural world. Archaeologists began to recognise similar patterns in the artefacts they recovered from the ground: styles changed with time, often moving from simple to complex forms, such as flat axes in the Early Bronze Age to socketed axes by the Late Bronze Age. Observations like these fitted in with the development of ideas about biological evolution, which – at a broad level – seemed to show how simple organisms developed over time into complex organisms, with humanity as the pinnacle of evolutionary development.