Seasonality

Seasonality refers to the changes that occur in the local, regional, and planet-wide environment as our planet lurches through its solar year. In temperate regions, spring turns to summer, summer to fall, fall to winter to spring again. But environmental changes occur seasonally everywhere on the planet to some degree, even at the poles, even at the equator. Archaeologists are interested in seasonality with respect to the adaptations that humans have created over the past 12,000 years to cope with and survive those changes. Seasonality is thus a core concept in for studying and understanding ancient farming technologies.

Modern Technology and Adaptations

Modern people notice when the weather changes throughout the year: We might have to shovel the snow off the driveway or pull out our summer clothing. But we—at least those of us in the so-called first world—aren't as a rule intimately involved in tracking changes in animal and plant behavior, building insulated housing, and making or repairing warm clothing. We have a calendar for tracking that. We might see a specific type of food disappear from our store shelves, or, more likely, a steeper price for the same food depending on the time of year, but if we notice it's not a serious loss.

Undeniably, modern technology and global trade networks have softened the impact of the changing seasons. But that was not the case up until relatively recently. For pre-modern people, temperate climate seasonal changes sharply affected availability to crucial resources, and if you didn't pay attention, you didn't survive long.

Coping with Seasonality

In temperate or colder climates, some—maybe most—natural and cultural events are tied to the natural changes that occur from season to season. Animals migrate or hibernate, plants go dormant, being outside of shelter is problematic. Some cultural groups in the past responded to the oncoming winter seasons by constructing storage facilities for safely storing summer crops, by building and moving into different types of houses, still others by temporarily relocating to warmer or cooler climates.

In a fairly broad but nonetheless meaningful way, calendar systems and astronomical observatories were created to respond to the demands of seasonality. The more closely you could predict when the seasons arrived, the better you could plan for your survival.

One result is that religious ceremonies associated with the movements of the sun, moon, and stars were scheduled for different seasons. Solstices and equinoxes were celebrated with specific rites at specific seasons of the year: indeed they still are. Most religions celebrate their highest holy days at the winter and summer solstice.

Dietary Changes

Much more than today, diets changed throughout the year. Seasons determined what kinds of foods were available. If you were a hunter-gatherer, you needed to know when a particular fruit was available, when the deer were likely to migrate through your area and how far they were likely to go. Farmers knew that different agricultural crops required planting and would ripen at different times of the year.

Planting a variety of crops, some of which ripened in spring, some in summer, and some in fall, resulted in a more reliable system of resources to get the groups through the year. Pastoralists needed to recognize when different animals gestated at different times of the year, or when they produced their woolliest coats, or when the herd needed to be thinned.

Tracking Seasonality in Archaeology

Archaeologists use the clues left in artifacts, animal bones, and human remains to identify the effects of seasonality on human cultures and the adaptations those cultures wielded. For example, an archaeological midden (trash heap) might contain animal bones and plant seeds. Determining in what season those animals were killed or those plants harvested allows us to get closer to understanding human behaviors.

To identify the season of death for a plant or a human, archaeologists can track seasonal changes recorded as growth rings. Many if not most living things record seasonal changes the way tree rings do. Animal teeth—human teeth too—record recognizable seasonal sequences; individual animals born in the same period of the year have the same pattern of growth rings. Many other organisms such as fish and shellfish also record annual or seasonal growth rings in their bones and shells.

Technological advances in identifying seasonality have included stable isotope analysis and ancient DNA changes in animals and plants. Stable isotope chemical balances in teeth and bones change with dietary input. Ancient DNA allows a researcher to identify specific species of animals and then compare those seasonality patterns with known modern patterns.

Seasonality and Climate Change

Over the past 12,000 years or so, humans have constructed controls to plan for and adapt to the changing seasons. But we are all still at the mercy of climate changes that result both from natural fluctuations and cultural choices made by people. Droughts and flooding, storms and wildfires, diseases which evolve from humans living in close proximity to one another and animals: All of these are in part climate-driven woes that had to be accounted for in the past, and need to be accounted for in the present and future as adaptations for survival.

Understanding how our ancestors adapted may well provide guidance to our ability to adapt in the future.

Sources

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