Book summary “After the ice”: summary

Introduction

You live in a world shaped by the end of the last ice age, yet you rarely consider how climate change forged human society. You might wonder how our ancestors shifted from mobile foragers to sedentary farmers and city builders. Steven J. Mithen answers this through a global journey across continents, following the footsteps of Victorian polymath John Lubbock to explore the sweeping transformation of human history between 20,000 and 5000 BC.

Human history experienced its coming of age between 20,000 and 5000 BC as global warming transformed mobile hunter-gatherers into sedentary farmers, town builders, and civilizations.

The book explores this vast epoch through five distinct environmental and cultural phases.

• How did Milankovitch cycles and ice cores record the end of the ice age?
• What drove Natufian hunter-gatherers to build permanent villages in the Mediterranean oak woodlands?
• Why did monumental sanctuaries and trade networks emerge before full-scale farming?
• How did coastal catastrophes like the flooding of Doggerland reshape European recolonisation?
• Which independent paths led communities in the Americas, Asia, and Africa toward agriculture and pastoralism?

1. The Ice Age World and Climate Science

Human history experienced its coming of age between 20,000 and 5000 BC with the emergence of farming, permanent towns, and civilization. While human evolution spans millions of years and the modern creative mind evolved by 50,000 BC, significant historical development did not occur until the global warming period following the last glacial maximum.

Global warming and the transition from glacial states are driven by Milankovitch orbital cycles and recorded via oxygen isotope ratios in ice cores.

Climate Science and Ice Cores

Natural global warming and the transition from glacial to interglacial states are driven by regular alterations in the earth's orbit around the sun. Milutin Milankovitch demonstrated that orbital eccentricity changes every 95,800 years, tilt varies every 41,000 years, and axial wobble has a 21,700-year cycle, which alter seasonality and trigger ice sheet growth or melting. The 41,000-year tilt inclination change operates between 21.39 and 24.36 degrees.

Global temperature variations across prehistory are reconstructed using oxygen isotope ratios extracted from ice cores as an indirect proxy measure. The ratio between 16O and 18O isotopes records relative deviations from a laboratory standard, where high values indicate warm and wet periods while low values indicate cold and dry conditions. The Greenland ice core record documents the late-glacial interstadial, the Younger Dryas dip, and the dramatic temperature rise at 9600 BC marking the start of the Holocene. The late-glacial interstadial spans from 12,700 to 10,800 BC, while a noticeable dip in the Holocene climate occurs at 6200 BC.

Radiocarbon dating establishes the age of organic archaeological remains by measuring the ratio of stable carbon isotopes to decaying carbon-14. Living organisms absorb carbon isotopes in atmospheric ratios, but upon death, carbon-14 decays at a known rate while other isotopes remain stable, though dating is limited to samples younger than 40,000 BC. Radiocarbon dates must be calibrated against independent dating methods like tree rings and uranium-thorium dating of coral to align with true calendar years. At 20,000 calendar years ago, a radiocarbon date is about 3,000 years too young, and by 12,500 years ago, it is about 2,000 years too young.

You can apply laboratory procedures when you prepare samples for chronology:

• find items in close association with datable material such as animal bones, plant remains, or ideally charcoal;
• ensure sufficient carbon-14 remains in the sample and that it dates no earlier than 40,000 BC;
• calculate the mean and standard deviation for the radiocarbon date expressed in years BP;
• calibrate the radiocarbon date using dendrochronology or other means to convert radiocarbon years into true calendar years BC.

At the Pushkari site in Ukraine, inhabitants constructed igloo-like structures using mammoth leg bones, jawbones, and tusks to withstand freezing temperatures near the glaciers. At Pushkari, five dwellings formed a circle with entrances framed by mammoth tusks, and residents hunted isolated reindeer while utilizing every part of the animal for food, clothing, and fuel. The site was located 250 kilometres south of the glaciers, experiencing minus 30 degrees Celsius winter temperatures and 9 months of severe winter.

2. Village Life in the Oak Woodland

Prehistoric hunter-gatherers manufactured small, standardized stone tool parts called microliths, which served as arrow barbs and knife insets over millennia. Craftspeople worked flint nodules using hammer-stones to produce long, thin blades, which were then meticulously chipped into tiny microliths and inserted into reeds or bone hafts. Across western Asia, shared styles of microliths define archaeological cultures like the Kebaran.

Andy Garrard excavated dense scatters of flint flakes, microliths, and basalt grinding stones in the Azraq basin at Wadi el-Uwaynid, demonstrating repeated seasonal occupation by hunter-gatherers.

You can manufacture microliths using specific techniques:

• Shape flint nodules using hammer-stones to detach thick crust flakes.
• Carefully remove long, thin blades from around the edges of the cores.
• Chip tiny flakes off the blades using pointed stones to create microliths of various shapes.
• Insert the finished microliths into reed arrow hafts or bone knife handles using resin.

The flint blades measured 5 to 10 centimetres. Wadi el-Uwaynid was located 10 kilometres from Azraq Lake.

The First Villages

The Natufian culture marked the emergence of permanent year-round villages in the Mediterranean oak woodlands, featuring semi-subterranean stone houses and intensive plant processing.

Unlike earlier mobile camps, Natufian communities built structured subterranean dwellings, utilized large boulder mortars for grinding nuts and wild cereals, and buried their dead with rich ornaments. Between 12,500 and 11,000 BC, rich and predictable plant and animal resources allowed groups like those at Abu Hureyra and ‘Ain Mallaha to abandon a mobile lifestyle in favor of permanent settlements despite social tensions and waste accumulation.

Jean Perrot excavated dwelling 131 at the Natufian village of 'Ain Mallaha, discovering stone walls, hearths, bone sickles, and a cemetery containing richly decorated burials including an elderly woman with a puppy. Dwelling 131 had an approximate diameter of 9 metres. Gordon Hillman found 157 different species using flotation methods at Abu Hureyra, where inhabitants lived in sunken circular dwellings and hunted massive passing herds of gazelle during the summer months.

The date range for the rise of hunter-gatherer sedentism at Abu Hureyra spans 12,300 to 10,800 BC.

Agricultural Origins

Natufian harvesters collected wild cereals using flint-bladed sickles while the plants were still unripe, which inadvertently prevented the genetic shift toward domesticated non-brittle strains.

Wild cereals naturally shatter when ripe to scatter seeds, whereas domesticates remain intact. Romana Unger-Hamilton and Patricia Anderson replicated Natufian harvesting techniques on Mount Carmel and around the Sea of Galilee, using microscopic sickle-gloss analysis to confirm that Natufians harvested unripe cereals where brittle plants had not yet dropped their seeds. Rare non-brittle mutants were not disproportionately selected, and a sedentary lifestyle meant you relied on natural growback rather than sowing new plots, delaying agricultural domestication for millennia.

You can follow traditional processing steps for wild cereals:

• Cut wild cereal stalks at their base using flint-bladed sickles to acquire both straw and grain.
• Beat the harvested ears into wooden bowls to release the spikelets.
• Add red-hot stones and swill them around to parch the spikelets and make them brittle.
• Empty the parched spikelets into wooden mortars and crush them to release the grain.
• Agitate the crushed mixture on bark trays to separate and discard the chaff.
• Grind the cleaned grain into flour using mortars, mix with water, and cook as flat bread-pancakes on hot stones.

Computer simulations reveal that transforming wild wheat into domestic variants requires a theoretical minimum of 20 cycles of harvests under ideal conditions, with 200 to 250 years representing the most likely realistic period for plant domestication transitions.

The thousand-year drought of the Younger Dryas destroyed early sedentary villages and forced a return to mobility. An influx of glacial meltwaters into the North Atlantic caused a severe cold and dry period that decimated woodland and plant productivity just as human population levels peaked. Sites like ‘Ain Mallaha, Hayonim, and Abu Hureyra were abandoned, and their inhabitants returned to transient campsites between 10,800 and 9600 BC.

Hard times during the Younger Dryas drove people to intensify plant care, unintentionally creating the world's first domesticated cereals. As wild plant foods declined, groups invested more effort in weeding, tending, and harvesting wild cereals, which eventually transformed them into domestic crops that waited for the harvester. Gordon Hillman identified domesticated rye grains dated between 11,000 and 10,500 BC alongside cultivated soil weeds at Abu Hureyra before its abandonment. Global temperatures then rose by 7 degrees Celsius in less than a decade at 9600 BC.

3. Pictograms, Pillars, and Complex Towns

Ideological shifts, monumental sanctuaries like Göbekli Tepe, and trade networks preceded the full development of settled farming communities.

Jacques Cauvin argued that the worship of deities and the awe of wild animals emerged before farming, motivating people to gather and cooperate. This is supported by monumental ritual architecture and symbolic codes created by hunter-gatherers who still relied entirely on wild resources. At Mureybet and Jerf el Ahmar, early shrine-like structures and wild cattle skulls built into walls predated domestic agriculture.

Monumental Sanctuaries

Klaus Schmidt led excavations at Göbekli Tepe in southeast Turkey, revealing circular sunken structures with carved pillars depicting animals and symbols. This site functioned as a monumental ritual mountain sanctuary where scattered hunter-gatherer groups gathered periodically for religious purposes.

Constructed by people who relied entirely on wild game and plants, the site features massive T-shaped limestone pillars weighing up to seven tons, with unexcavated monoliths estimated at 50 tons in nearby quarries. Many limestone pillars stand 8 feet high. An unfinished pillar in the quarry measures 20 feet long.

As populations grew and farming intensified, societies moved away from transparent, communal village layouts. The Pre-Pottery Neolithic B, or PBNB, period brought a transition from small circular huts to large, multi-room rectangular buildings and towns. This evolution reflects a profound social shift from group-oriented sharing to family-centric autonomy. Multi-room rectangular homes with specialized basements and restricted access allowed individual households to store their own grain surpluses and manage private economic lives.

Diana Kirkbride excavated Beidha, uncovering a transition from circular huts to a town of two-storey rectangular buildings with specialized workshops and storage. She uncovered a total of 65 buildings. The later Neolithic town of Basta attained a size of 12 hectares.

The domestication of goats and sheep completed the shift to a farming lifestyle, driven by managed herding and selective culling strategies. An abundance of small goat bones dominated the faunal assemblages at sites like Beidha, indicating managed herds rather than hunting. Herders culled animals that reached full size before consuming too much forage, and selectively killed young males rather than focusing on milk production early on.

Brian Hesse and Melinda Zeder studied nearly 5,000 goat bones from Ganj Dareh in central Iran, identifying the high slaughter rate of young males as a sign of domestication. At Beidha, 80 per cent of animal bones belonged to goats. By 7500 BC, Abu Hureyra shifted entirely to managed herds.

Anatolian Urbanism

Neolithic communities practiced ancestor worship and memorialization by exhuming buried bodies after several years to remove, meticulously remodel, and display human skulls. Living relatives would reopen graves, remove the skull of a deceased family member, patch the floor below, and decorate the skull using fine white plaster, red paint, and inset cowrie shells for eyes before displaying it in the house. At Jericho, Kathleen Kenyon discovered seven plastered skulls within a single pit, featuring modeled faces and cowrie shell eyes, which served as portraits of revered household founders.

The massive farming town of 'Ain Ghazal distinguished itself through the production of large, human-like plaster statues that were eventually buried beneath floors. Spanning the date range of 7500–6300 BC, the townspeople manufactured large statues by coating reed bundles with pure white plaster, featuring wide-open eyes with deep black centres, which were periodically carried in public processions and ceremonially buried in pits inside abandoned houses. Gary Rollefson discovered two caches of these statues at 'Ain Ghazal around 6500 BC, including twelve statues and thirteen busts in the first cache, and three spectacular busts of a two-headed figure in a second cache.

James Mellaart excavated the 32-acre mound of Çatalhöyük between 1961 and 1966, revealing uniform domestic layouts and elaborate wall paintings. The site developed as a massive, tightly packed agglomeration of abutting residential structures lacking ground-level entrances, relying entirely on rooftop access. Houses were built flush against one another with continuous perimeter walls, forcing residents to enter buildings via wooden ladders through trapdoors on flat mud-brick roofs during the peak period of 7000 BC, across a mound length of 450 metres.

4. European Recolonisation and Coastal Catastrophes

As ice sheets retreated, pioneers recolonized northern Europe, while post-glacial sea-level rises drowned vast coastal plains and doggerland.

Recolonisation of Northern Europe

The application of Accelerator Mass Spectrometry (AMS) radiocarbon dating to cut-marked animal bones has enabled researchers to trace the precise chronology of human recolonization northward into Europe following the glacial thaw. By dating bones proven to be contemporary with human presence via cut marks, Rupert Housley and colleagues established that human groups expanded from southern refuges at an average rate of one kilometre per year after 15,000 BC, leading to a distinct two-stage expansion process. Rupert Housley published over a hundred new AMS radiocarbon dates from 45 sites across northern Europe, providing the first definitive timeline for the northward push into Britain and Germany during the Bølling warm phase.

Detailed archaeological reassessment of ice-age sites like Creswell Crags demonstrates that northern European pioneers relied primarily on specialized trapping of arctic hares rather than megafauna hunting. At Robin Hood Cave in Creswell Crags, hunters used sinew noops placed near willow thickets to catch arctic hares, turning their leg bones into awls and needles and their fur into clothing linings. You can follow these practical survival steps when tracking small game in cold northern environments:

• Inspect willow leaves and grass stems chewed or broken by resting hares to find feeding spots.
• Insert a stripped branch into the ground near the feeding area.
• Attach a loop of sinew to the branch where the hare is expected to feed next.
• Retrieve the caught hare, harvest its sinews for sewing thread, and turn leg bones into awls and needles.

The Mesolithic period in Europe began in early Holocene woodlands, marking a transition from brute-force mass animal slaughter to stealth hunting and forest foraging. Sir Grahame Clark excavated the waterlogged Mesolithic lakeside site of Star Carr in Yorkshire, discovering exceptional preservation of wooden tools, bone harpoons, and red deer headdresses. The 20,000-year-old tradition of European cave painting and animal carving ended abruptly with global warming because dense woodlands changed hunting patterns and eliminated the need for mass-kill coordination. John Lubbock visits the once-great ice-age art cave of Mas d’Azil at 9000 BC only to find people merely gutting fish with plain antler harpoons and daubing simple pebbles with paint blobs rather than creating fine animal carvings.

Coastal Catastrophes

Rising sea levels at the end of the ice age drowned Doggerland, while a massive submarine landslide triggered a devastating tsunami across northern Europe. In 1931, the trawler Colinda hauled up an elegant barbed antler point from North Sea peat beds, revealing the drowned Mesolithic world of Doggerland. The sudden breaching of the Bosphorus channel caused a catastrophic deluge that merged the Mediterranean and the Black Sea, submerging vast farming and hunting lowlands. A gigantic wall of marine water built up on the western face of the Bosphorus channel before bursting with the force of two hundred Niagara Falls.

The Linearbandkeramik (LBK) farming culture expanded rapidly across central Europe by clearing woodlands, building timber long houses, and domesticating cattle. Houses from Cuiry-les-Chaudardes in the Paris basin appear nearly identical to those in Miskovice in the Czech Republic, located almost 1,000 kilometres away.

5. Global Transitions in the Americas, Asia, and Africa

Diverse global communities adapted to post-glacial environmental shifts through independent plant domestication, pastoralism, and maritime foraging.

Tom Dillehay uncovered wooden structures and plant remains at Monte Verde in southern Chile dated to about 12,500 BC. This site provided unequivocal evidence of pre-Clovis settlement, dismantling the Clovis First theory. In 1997, David Meltzer, Vance Haynes, James Adovasio, and Dena Dincauze visited the site and verified the dates. North America lost seventy per cent of its mega-fauna at the end of the Pleistocene. Thirty-six species became extinct, including mammoths, mastodons, and giant ground sloths.

Peopling of the Americas

Kent Flannery discovered Guilá Naquitz cave in the Oaxaca valley in January 1966. Between 8500 and 6000 BC, small family groups used the site as an autumn campsite. Over time, practices like weeding led to domesticated squash, maize, and beans. Bruce Smith later identified larger squash seeds dated between 7500 and 6000 BC as domesticated specimens. High Plains hunter-gatherers organized cooperative stampedes to hunt Bison antiquus.

• Position the bravest hunters behind boulders at the cul-de-sac end of a gully while others watch from the sides with spears.
• Shout loudly and bang sticks to stampede bison into the gully.
• Throw spears to pierce the heart and lungs as the animals charge.
• Cut the skin of each animal's belly from tail to throat using large stone flakes.
• Remove innards, save favored organs, and wipe grease and blood from stone tools on thick bison hide.
• Cut meat into long thin strips and hang them immediately from trees and wooden racks to form a protective crust against flies.

The Koster site in the Illinois valley demonstrates how hunter-gatherers built permanent settlements. Discovered on Theodore Koster's farm in 1968, thirteen distinct occupational layers created 10 square metres of deposits. By 5000 BC, Koster developed into a large permanent village supporting deer hunting and trade items.

Asian and African Developments

Anping Pei excavated Pengtoushan in 1988, finding domestic rice traces dated to at least 7500 BC. Rice farming originated in the middle stretches of the Yangtze River in China.

• Broadcast baskets of stored rice seed over newly exposed silt as annual floodwaters recede without preparing the soil.
• Remove tall weeds from the crop in May.
• Harvest plants in early August as floodwaters approach by pulling them from the ground.
• Thresh dry plants by striking the ears of grain to separate stalks for thatch and matting.
• Hullo the grain by rubbing tough outer husks with wooden slabs, then winnow to isolate the edible rice.

Genetic research by Daniel Bradley and Ronan Loftus confirmed that domestic cattle in Africa had an independent origin around 9000 BC. In the Western Kalahari Desert, prehistoric foragers extracted hibernating bullfrogs.

• Search the ground around bush roots for spider webs strung across tunnels in the sand.
• Dip a digging stick into the hole and twist it to wind the web around its tip.
• Dig into the sand once it becomes moist and thrust a hand into the hole.
• Pull out the bullfrog by its leg and strike it swiftly with a digging stick before it bites.

10 Key Ideas

1. Natural global warming and the transition from glacial to interglacial states are driven by regular alterations in the earth's orbit around the sun.
2. Radiocarbon dating establishes the age of organic archaeological remains by measuring the ratio of stable carbon isotopes to decaying carbon-14, though dates must be calibrated against independent methods.
3. The Natufian culture marked the emergence of permanent year-round villages in the Mediterranean oak woodlands, featuring semi-subterranean stone houses and intensive plant processing.
4. Ideological shifts, monumental sanctuaries like Göbekli Tepe, and trade networks preceded the full development of settled farming communities.
5. Natufian harvesters collected wild cereals using flint-bladed sickles while the plants were still unripe, which inadvertently prevented the genetic shift toward domesticated non-brittle strains.
6. As ice sheets retreated, pioneers recolonized northern Europe, while post-glacial sea-level rises drowned vast coastal plains and Doggerland.
7. North America lost seventy per cent of its mega-fauna at the end of the Pleistocene as thirty-six species became extinct, including mammoths, mastodons, and giant ground sloths.
8. Tom Dillehay uncovered wooden structures and plant remains at Monte Verde in southern Chile dated to about 12,500 BC, providing unequivocal evidence of pre-Clovis settlement.
9. Diverse global communities adapted to post-glacial environmental shifts through independent plant domestication, pastoralism, and maritime foraging.
10. You live in a world shaped by the end of the last ice age, yet you rarely consider how climate change forged human society.