Friday, January 10, 2020

When We Became Humans: Our Incredible Evolutionary Journey by Michael Bright

When We Became Humans traces what scientists be current theory of the evolutionary journey of humans from primates in this book for younger readers. Michael Bright begins by defining a number of terms that readers will encounter in book: hominins, hominids, mammals, primates and halplorhines as well as explaining the nomenclature for assigning names in biology.

From there readers will begin their journey with the earliest known primate fossils from approximately 65 million years ago. These fossils tell us that
Moving on to the Age of Apes, readers learn about the theory that the ability to see colour may have evolved with the eating of fruit.

Questions such as How Do We Know Who Our Ancestors Were?, Why Walk Upright? are asked. Bright also touches on the use of DNA analysis in archeological exploration.

The skeleton of Lucy, a female from the hominin species Australopithecus afarensis (which was discovered in 1974) is over three million years old. It is possible that Lucy was one of our ancestors. The story then moves from Lucy to Homo habilis, "handy man" who lives during the Pleistocene (about 1 to 2 million years ago).  The use of fire and of more sophisticated stone tools to hunt and butcher food occurred soon after, around 1 million years ago.  Homo erectus, "upright man" was the hominin who is considered to have made great evolutionary strides. Homo erectus had a much larger brain and is considered to be intelligent and "more human like than any who had gone before."  Their bodies were considered to have proportions similar to that of modern humans.

The section on Neanderthals, a hominin who lived between 430,000 and 250,000 years ago, but who is not believed to be our direct ancestor, explores how they might have looked, the type of tools they used, what they ate, where they lived and what eventually happened to them. This then takes the reader to modern humans, Homo sapiens who appeared some 300,000 years ago. Homo sapiens are believed to have evolved out of Africa and then traveled throughout the world to  Western Asia, Europe, Australia, and eventually to the Americas.

From this point on, Bright focuses on modern humans, detailing the skills prehistoric humans developed to help them survive and thrive. These skills include becoming proficient hunters, developing glue, inventing the wheel, developing agriculture and permanent settlements, domestication of animals and the development of trade. As civilization developed, art, monuments, religious rituals and the written word were developed. How human evolution continues is an interesting and unexplored question.

Discussion

When We Became Humans offers younger readers a good overview of how archeologists believe humans evolved over millions of years. It presents, in very simple format, the series of fossilized skeletal remains of hominins that have been discovered and insight they provide to archeologists. Bright not only describes these hominins and how they may have looked but also portrays how scientists believe they may have lived, and how their surroundings pushed them to adapt and learn new skills. For example he mentions how early hominins lived in warm climates but as they developed and began moving northward from Africa into Europe, the colder climate led them to learn how to build more advanced shelters.

When We Became Humans also portrays the difficulty that scientists have encountered in unravelling the puzzle of our ancestry. For example,  the hominin species, Homo heidelbergensis is believed by some scientists to be our most recent ancestor, but others believe that H. heielbergensis is the ancestor of the Neanderthals, while still others believe they are not a separate species at all. As Bright states, "The human story is so complex that nobody is sure who is right."

Many interesting facts and details are incorporated into the text. For example, details about how wolves were domesticated to become the dogs that ancient hunters used, or how "All modern Asian rice varieties can trace their origin back to the Pearl River Valley in China about 13,500 year ago." are just two examples of the many interesting and very relevant facts woven into the story of human evolution.

Bright helps his young readers understand how archeology draws from many other sciences to understand the past. For example he briefly explains how fossils are made, and how scientists use the rocks they are found in to date fossils. This helps archeologists understand new discoveries in relation to previous ones.

Readers learn that modern archeology utilizes modern technology such as CT scans and DNA analysis. The use of these tools provides scientists with information they might never have uncovered. "In a cave in Belgium, for example, there were no fossil skull fragments or other parts of a skeleton present, yet scientists were able to find minute amounts of DNA in the sediment of the cave floor -- probably from blood, pee, or poop -- revealing that ancient humans had once lived there."

Hannah Bailey's muted artwork illustrates many of the concepts Bright presents without detracting from the text. A chart of the Human Family Tree and a map showing the migration route of humans and our ancestors out of Africa close out the story. As Bright states, " The epic story of humans has been long and complex. The family tree is not a neat straight line from one ancestor to the next, but one of many branches and frequent dead ends." He notes that our recent chapter out of Africa, "features a cast of characters that constantly change as new discoveries are made." Those interested in human history and who wonder about how we came to be, are sure to find When We Became Human an engaging read.

Readers looking for more information on human evolution are directed to the Smithsonian National Museum of Natural History website.

Book Details:

When We Became Humans: Our Incredible Evolutionary Journey by Michael Bright
Lake Forest, CA: Quarto Publishing     2019
64 pp.

No comments: