Chapter 1: The Ice Age Landscape

The Earth during the glacial periods was drastically different from what we experience today. Recent studies have traced humanlike ancestors back to around two million years ago, eventually leading to the emergence of Homo sapiens approximately 300,000 years ago in Eastern Africa. While the specifics of their migration patterns are debated, these early humans spread across the globe, showcasing an impressive adaptability to diverse climates and environments. This ability has been crucial for our survival through various significant historical events.

Current estimates suggest that human migration occurred over thousands of years, with the acronym 'kya' representing thousands of years ago. It's worth noting that emerging theories indicate humans may have reached the Americas much earlier than previously thought, possibly via Polynesia. Our capacity to thrive in various environments is essential, as Earth's geological and climatic conditions have shifted dramatically over time. Studies in geology and paleoclimatology reveal that over the last million years, our planet has undergone multiple ice ages, occurring in roughly 100,000-year cycles. During these periods, global temperatures can drop by as much as 6 degrees Celsius, leading to extensive glacial coverage.

The precise causes of these ice ages remain a topic of debate, but they are generally linked to Earth's orbital cycles. My research focuses on the intricate relationship between these cycles and climate changes, as they alone cannot fully explain such drastic shifts. Ice ages result in significant alterations to local climates, compelling early humans to adapt to much colder and drier conditions in various regions. Interestingly, some areas became more hospitable during these cold periods than they are today. Let us examine how different human groups adjusted to these environmental changes, particularly during the last Ice Age, which reached its peak around 20,000 years ago.

Studying early human life is challenging due to limited evidence. For instance, numerous human footprints found in the Grotta della Bàsura cave system in Italy date back roughly 14,000 years, a time when Earth was still enduring an Ice Age but beginning to warm. Researchers employed various modern techniques to document the movements of several individuals within this cave. This remarkable study provides valuable insights into human life during challenging times, suggesting that some exploration may have stemmed from sheer curiosity.

The scientific team identified two adults, a teenager, and two children, tracing their journey through the cave and deducing that they used torches for illumination. Notably, all the explorers were barefoot, and footprints allowed researchers to infer when they knelt. This is just one of many archaeological sites that contribute to our understanding of early humans. Evidence indicates they had access to various tools and involved children in potentially risky activities, marking this period as the Upper Paleolithic. I highly recommend reviewing the open-access paper detailing these findings, which features captivating images and even a video theorizing their path through the cave.

The first video, "Humans and the Ice Age," explores the fascinating relationship between early humans and the harsh conditions of the Ice Age. It delves into how they adapted and survived during this challenging period.

As the planet warmed towards the end of the Ice Age, humans thrived, but not all species were so fortunate. The woolly mammoth, for instance, faced gradual extinction as the climate changed. These majestic creatures once roamed extensive regions known as the mammoth steppe, which stretched from Spain to Siberia and characterized by a cold, dry climate with abundant grasses and shrubs.

Mammoths first emerged around six million years ago, flourishing during ice ages when their habitat expanded. However, their numbers declined during warmer interglacial periods, despite their survival through several such cycles. The recent interglacial period, however, proved catastrophic for them, likely due to increased human activity. Evidence suggests that early humans actively hunted woolly mammoths, with research indicating that hunter-gatherer camps were often located along mammoth migration routes. Blood analysis from Stone Age tools has even revealed traces of mammoth blood on hunting spears.

The extinction of these large mammals, collectively referred to as 'megafauna,' is a topic of ongoing debate. Over 80% of these species vanished as the last Ice Age ended. The image at the beginning of this article depicts the lesser-known woolly rhino. The presence of these large animals provided early humans with a rich source of meat and materials, and their seasonal migrations influenced human habitation across vast areas.

Was human activity responsible for the extinction of the mammoth and many other large species at the end of the Ice Age? This question remains open for discussion, but it is likely a combination of human influence and climate change that created the ideal conditions for extinction. Human presence invariably alters the ecosystems we inhabit, often resulting in the first losses among the largest and most specialized species.

Going Further

I hope you found this exploration insightful! Understanding how ancient humans lived presents numerous challenges, but environmental clues help us piece together their story. We will likely always have questions about our early origins. For those interested in delving deeper, I recommend the following resources:

"Ice Ages: Solving the Mystery" is an excellent book detailing how scientists uncovered the history of ice ages through geological evidence. It features insightful science from leading experts in the field.

"Growing Up in the Ice Age: Fossil and Archaeological Evidence of the Lived Lives of Plio-Pleistocene Children" offers a glimpse into Ice Age cultures through the experiences of children, providing a wealth of fascinating information.

If you wish to stay updated on similar topics, consider following my work or subscribing to my email list for weekly insights on science and mathematics.

The second video, "A Brief History Of How Homo Sapiens Survived The Last Ice-Age," provides an overview of the strategies and adaptations that allowed Homo sapiens to endure one of the most challenging periods in Earth’s history.