Modern archaeology has its origins in Europe in the mid 19th century, where it developed soon after the scientific advancement of geology, which had shown that the Earth was billions rather than thousands of years old, as was then commonly believed. Soon after this, in 1859, Charles Darwin's On the Origin of Species was published, outlining his theory of evolution, eventually leading scientists to believe that humanity was in fact millions of years old, thereby providing a time limit within which the burgeoning archaeological movement could study. Meanwhile, in 1836 the Danish historian Christian Jürgensen Thomsen published A Ledetraad til Nordisk Oldkyndighed (Guideline to Scandinavian Antiquity) translated into English in 1848, in which he proposed the idea that the European prehistoric could be divided up into a three age system; the Stone Age, Bronze Age and Iron Age, based upon the materials used by humankind. It was these three concepts of human antiquity, evolution and the Three-Age system that are often thought of as the building blocks for modern archaeology.
Soon the early archaeologists began to investigate various areas around the world, with the study of ancient Aegean civilization being stimulated by the excavations of Heinrich Schliemann at Troy, and of Arthur Evans at Crete, whilst John Lloyd Stephens was a pivotal figure in the rediscovery of Maya civilization throughout Central America. However, the methodologies employed by these archaeologists were highly flawed by today's standards, often having a eurocentric bias, and many early European archaeologists often relied on anthropological and ethnographic accounts provided by the likes of Edward Tylor and Lewis Henry Morgan, thereby comparing contemporary "savage" peoples like the Native Americans with the historical peoples of Europe who lived in similar societies. Soon the new discipline of archaeology spread to North America, where it was taken up by figures like Samuel Haven and William Henry Holmes, whom excavated ancient Native American monuments.
Further advancements in archaeological field methodology arose in the late 19th century. One of the pioneering figures in this was Augustus Pitt Rivers, who meticulously excavated on Cranborne Chase in southern England, emphasising that it was not only items of beauty or value that should be recorded, but mundane items as well; he therefore helped to differentiate archaeology from antiquarianism. Other important archaeologists who further refined the discipline in the late 19th and early 20th centuries were Flinders Petrie (who excavated in Egypt and Palestine), Sir Mortimer Wheeler (India), Dorothy Garrod (the Middle East), Max Uhle (Peru) and Alfred Kidder (Mexico). Further adaptation and innovation in archaeology continued throughout the 20th century, particularly in the 1960s, when maritime archaeology was popularised by George Bass, urban archaeology became more prevalent with redevelopement in many European cities, and rescue archaeology was developed as a result of increasing commercial development.