A Victorian era cartoon published in The Hornet, the satirical English magazine in which Charles Darwin was famously portrayed as “a venerable orang-outang.” Courtesy of http://www.aidanhiggins.com/images/chimps.jpg

This infant patas monkey instinctively clings to its mother’s fur, where it will ride upside-down for the first several months of its life. Photo by Richard Dutton, richard@dutton.me.uk. Reprinted with permission.

The Laetoli footprints furnished indisputable evidence that early hominids were fully bipedal and have been walking on two legs for millions of years. © 2015 John Reader. Reprinted with permission.

The bonobo, our closest primate relative, can stand and walk upright when carrying things with its forearms. But its bent knees reveal that its legs are designed for quadrupedal locomotion. © Frans Lanting/ www.lanting.com. Reprinted with permission.  

Homo erectus fossils collected by Eugène Dubois in Java. These were the first fossils discovered of the emerging human Homo erectus, which Dubois dubbed “Java Man.” Wikimedia Commons.

A beaver lodge in winter. Although its brain is only slightly larger than a walnut, the beaver constructs a complex dwelling, complete with cleverly concealed entrances and breathing holes. Illustration by Mike Storey. Reprinted with permission.

The three types of lice that infest the human body. Top left: the human body louse; top right: the human head louse; bottom: the human pubic louse. Human head louse: Creative Commons Attribution- ShareAlike 3.0 files; human body louse and pubic louse: courtesy CDC DPDx—Centers for Disease Control—Laboratory Identification of Parasitic Diseases.

Marcelino Sanz de Sautuola and his daughter Maria, who together discovered one of the world’s largest and finest collections of prehistoric art, in Altamira Cave, Spain. Maria Sanz de Sautuola: Santander Prehistory Museum.

The Venus of Lespegue from France (left) and the Venus of Willendorf from Austria (right) date from the same time period, yet their artistic styles reflect the distinct cultures of these two different Paleolithic societies. Venus of Willendorf photo by Matthias Kabel, Creative Commons.

This cuneiform letter, written with a wedge-shaped stylus in soft clay, was sent to the king of the Mesopotamian city of Lagash, informing him of the death of his son in combat.  

Writing began in the Indus Valley with symbols carved onto clay seals (A) often combined with imagery (B) and stamped onto soft clay or wax (C). The use of repeated symbols (D) is evidence that the Indus script was a true written language. A, B, and C: permissions granted by GNU Free Documentation License 1.2; D: permission granted by GNU Free Documentation License 1.2 and the Creative Commons Attribution-Share Alike 3.0 Unported License.

The extremely complex hieroglyphics of Mayan civilization were written on panels of flattened bark (top) and also carved into the facades of stone temples (bottom). Bottom: Creative Commons Attribution Share-Alike 3.0 License.

The “verge and foliot” escapement (A) was used for 350 years, but was eventually replaced by the pendulum and the more accurate “anchor” and “deadbeat” escapements (B) and (C). A: De Vick clock verge & foliot by Pierre Dubois, licensed under public domain via Wikimedia Commons; B: anchor escapement by George Henry Abbott Hazlitt; licensed under public domain via Wikimedia Commons; C: deadbeat escapement by Frederick J. Britten; licensed under public domain via Wikimedia Commons.

A wood-fired blast furnace of the type commonly used in sixteenth-century Europe.  

The UNIVAC Model 1103, designed for making scientific calculations, was announced by the Remington Rand Corporation in February of 1953.

Ice cores from Antarctica’s Vostok Research Station show that high concentrations of atmospheric carbon dioxide have been closely associated with increased global temperatures during the past four hundred thousand years. Illustration by the author, after Vostok Petit data. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons.

The body language of these chimpanzees reflects the solidarity and familiarity they feel as members of the same social group. Courtesy of http://www.aidanhiggins.com/images/chimps.jpg

The discovery that chimpanzees make and use tools revolutionized scientific thinking about the origins of tool use. This chimpanzee is using a stick for fishing termites out of their nest. Photo by Mike Richey. Reprinted under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

Compare the blunt, stubby canine teeth of the early hominid Australopithecus afarensis (left) with the weapons-grade canines of our closest relative, the common chimpanzee (right). Left: © 2014 Skullduggery, Inc. Reprinted with permission; right: © 2014 Science Outreach, University of Canterbury, Christchurch, New Zealand. Reprinted with permission.

Professor Raymond Dart with the “Taung Child”—the first fossil of Australopithecus ever found. Wikimedia Commons.

The iconic Acheulean hand ax, made by emerging humans for hundreds of thousands of years. Its manufacture required the selection of a suitable stone and the mastery of a multistep process. Wikimedia Commons.

The forms of the various species of humans that were once believed to exist, as they were depicted in Carolus Linnaeus’s Systema Naturae. Wikimedia Commons.

The son of a Plains Cree chief in traditional ceremonial dress. Note the tailored clothing that covers almost the entire body of this hunter-gatherer from the North American Plains. Geraldine Moodie / Library and Archives Canada.

Map of Europe showing the minimum percent of the body that the Neandertals must have covered with clothing in order to survive in Europe between 70,000 and 50,000 years ago. Reprinted from Journal of Human Evolution, vol. 63, no. 6, Nathan Wales, Modeling Neanderthal clothing using ethnographic analogues, page no.786, copyright 2012, with permission from Elsevier.

A painting of extinct bison found by Maria de Sautuola in Altamira Cave. Originally rejected by paleontologists, these paintings are now among the most treasured examples of prehistoric art. Wikimedia Commons.

This horse’s head, carved from a section of reindeer antler, is fifteen thousand years old. It shows the prehistoric artists’ consummate skill in rendering the likeness of animals. Wikimedia Commons.

Egyptian hieroglyphics were carved in stone (top) and also written in a more simplified “cursive” form on sheets of papyrus (bottom). Permission granted by GNU Free Documentation License 1.2 and the Creative Commons Attribution-Share Alike 3.0 Unported License.

Forms of early writing in China, from (A) Jiahu, 6600 BC, (B) Dadiwan, 5800 BC, (C) Longshan, 3000 BC, and (D) the “oracle bone writing” of the Shang dynasty, 1200 BC. C: redrawn by Tomchen in 1989; D: replica of oracle turtle shell with ancient Chinese oracle scripts; licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons.

The wheel evolved from solid pieces of wood (A) to a three-piece design (B) that ultimately evolved into the multispoked wheel (C). Chariots had four- and sixspoked wheels (D and E). Decorated wheels (F) were used for ceremonial occasions. A–E: illustrations by the author; F: after chariot, image 16657, Florida Center for Instructional Technology. Reprinted with permission.

The screw press had been used since ancient times, but precision machining made it possible for Johannes Gutenberg and others to adapt the screw press for the task of printing on paper. William Caxton showing specimens of his printing to King Edward IV and his Queen. Licensed under public domain via Wikimedia Commons.

Charles Babbage’s “difference engine” was the most advanced calculating machine of its time. This version, designed in 1849, was built at the London Science Museum in 1989. Permission granted by GNU Free Documentation License 1.2 and the Creative Commons Attribution-Share Alike 3.0 Unported License.

Biosphere 2 was intended to demonstrate how humans could live on other planets, but instead it showed that life cannot be sustained once contact with the earth’s natural ecosystems is severed. Wiki bio2 sunset 001 by Johndedios. Licensed under Creative Commons Attribution 3.0 via Wikimedia Commons.

The global population of human hunters and gatherers stood at roughly five million people in 5000 BC and grew to 150 million over the next five thousand years. But when the industrial revolution began in 1800, the human population exploded, increasing from less than one billion to more than six billion people in slightly more than two hundred years.