Published in 2001, "The Nature of the Beast" by Bryan Sykes delves into tracing human ancestry through maternal lineage, specifically using mitochondrial DNA. This method of exploration uncovers fascinating insights into our genetic past and is central to the themes discussed in this book. Sykes' work provides a genetic perspective on historical mysteries surrounding the existence of creatures like apemen, Yeti, and Bigfoot, suggesting a deeper connection to our evolutionary story.

In addition to "The Nature of the Beast," Sykes has authored several other notable works that explore different aspects of genetic lineage. "Adam's Curse" (2003) emphasizes the paternal side through the Y-chromosome, while "Blood of the Isles" (2006) investigates the genetic history of Britain and Ireland, and "DNA USA" (2012) focuses on America. These books collectively illustrate the rich tapestry of human genetics and ancestry through various inherited traits and lineages, offering a comprehensive view of our past.