Agriculture emerged around 11,000 years ago in what’s known as  the “fertile crescent” – an area that extends from present-day Iraq down as far as Syria. About 15,000 years ago it was gradually starting to get warmer there too, and large-grained wild grasses started growing on the previously barren steppes. The hunters and gatherers were able to stay in one place for longer. But the climate wasn’t always so mild. Humans began to pick out the best grasses selectively and cultivate them, so that they could feed themselves well even when times were harder. These farmers lived in one place. They could store supplies and feed larger families.

Around 8000 years ago agriculture came to Europe along with farmers from Anatolia. There they met hunter-gatherers, usually living alongside each other. 4800 years ago there was a second wave of migration: cattle breeders with large herds came from the steppes in the east. They were far superior to the native population in terms of culture and technology.

There’s enough space for everyone!
8000 years ago Anatolian farmers encountered native hunter-gatherers in Europe. The newcomers were arable farmers, but still barely had any dairy cattle. The two groups lived side by side for at least 2000 years. Neither of them was particularly interested in living like the other:
The hunters and gatherers were very well nourished and healthy, for instance there was no evidence of tooth decay – after all they didn’t have grain, which turns into sugar when chewed. But they didn’t have many children because they had to be breast-fed for many years. The hunter-gatherers only needed to spend two to four hours a day to ensure their survival. So they had plenty of “leisure” time.
The farmer families on the other hand had to spend all day working hard. But they could feed far larger families and had significantly more children. They lived in settlements and owned property. If they had spent less time working, they would not have been able to feed their large families. In the occasional event of conflict, the hunter-gatherers got out of the way by moving into areas of little value to the farmers. There was plenty of space in the big forests.

The invention of agriculture
12,000 to 14,000 years ago hunter-gatherers in the area that’s now Israel and Jordan were already gathering wild grains. They used them to make flour. When there was a cold snap without much rain 13,000 years ago, food availability dwindled. This was presumably the reason that people began to select grains with particularly “good” qualities and to actively cultivate them. Around 10,500 years ago they were cultivating emmer wheat, a forerunner of the wheat we know today. Emmer has fixed ears, which means that the loose grains don’t fall to the ground anymore during harvesting – a characteristic that is useful for the farmers but would not make any sense for a wild grain. Barley has been around for a long time too: scientists at the Max Planck Institute for the Science of Human History in Jena worked in an international research team to compare 6000 year-old barley seed from the Dead Sea area with local varieties from the present day. They found barely any genetic difference. So the cultivation of cereal crops was already more or less as it is now in the Stone Age.
A grain of barley more than 6000 years old – found in a cave near the Dead Sea © nature genetics, DOI: 101038/ng.311
A barleycorn more than 6000 years old – found in a cave near the Dead Sea.

Change as a result of migration and idea transfer
As a result of gene analysis we now know that agriculture came to Europe around 8000 years ago with the immigration of Anatolian farmers. But who were these people and how did they know about agriculture? To find that out, scientists analysed prehistoric skeletons of the inhabitants of Anatolia that were up to 15,000 years old. The result: the Anatolian farmers are direct descendants of the local hunter-gatherers– their gene pool has remained stable for over 7000 years. So in this case the local population took on new ideas and cultural techniques, and modified their lifestyle.

New environment – new look
After the end of the last Ice Age 18,000 years ago, hunter-gatherers with dark skin and blue eyes lived in Central Europe for the following centuries. These humans ate fish and meat and thereby absorbed plenty of Vitamin D. The farmers who migrated from Anatolia to Europe 8000 years ago on the other hand had a diet consisting mostly of plants and therefore lacked Vitamin D. The human body can make this vitamin itself – but only if enough UV light is able to pass through the skin. However in northern latitudes that's only possible for people with pale skin. This meant that pale skin became an evolutionary advantage among the farmers. Especially as the strong UV protection of the dark skin that had developed in Africa was no longer so important in northern latitudes..
But why did the blue eyes persist? They have no practical benefit. Maybe this was an early beauty ideal, and people with blue eyes were more popular as partners?

Surprising consequences of the new diet
The sounds in human language are extremely diverse. For a long time it was assumed that all these sounds had already emerged around 300,000 years ago with the development of Homo sapiens. But a new study has shown that sounds like “f” and “v” only developed relatively recently – as a consequence of a new tooth position! Hunters and gatherers had an “edge-to-edge bite” due to the hard, tough food they ate. This meant that the incisors of the top and bottom jaws bit together exactly. But with the increasing spread of soft food a slight “overbite” became prevalent. The upper incisors now stood out slightly beyond the teeth of the lower jaw. It wasn’t until they had this tooth position that it was possible to form new sounds, which are now found in half the languages of the world. With these sounds the upper incisors touch the lower lip, for example when pronouncing “f”.
  http://© Tímea Bodogán
The type of diet influenced tooth position – and language (left: edge-to-edge bite, right: overbite).

The milk makes the difference
In mammals it’s actually only the infants that can digest milk. They use the enzyme lactase to break down the milk sugar (lactose) so that they can utilise it. At the adult stage this enzyme is no longer produced – consuming milk then causes serious digestion problems. 4800 years ago the migrants brought large herds of cattle across the steppe to Europe. The cattle farmers had a good additional nutrient source available to them: although they didn’t tolerate milk either, they could use it. This was because they had developed culinary practices with which they processed the milk into lactose-free products such as kefir, yoghurt or cheese.
Later there was an evolutionary coincidence: in some humans the gene that stopped the production of the enzyme lactase at the end of infancy changed. Those carrying this mutated gene now could drink milk even as adults.  In Central Europe the mutation for this “lactose tolerance” spread with pasture farming – at breath-taking speed! Nowadays around 85 per cent of Germans tolerate milk, whereas in China it’s only around five per cent.

The stories told by teeth
When and where do humans start to incorporate milk in their menus and systematically produce milk products? That’s something Christina Warinner, research group leader at the Max Planck Institute for the Science of Human History in Jena, would like to find out. To do this, she is analysing the tartar on ancient teeth. In the fossilised plaque she has found bacteria DNA as well as milk proteins. One thing of particular interest is a whey protein (beta-lactoglobulin). It is found in the milk of sheep, cows and goats, for example, – but not in human breastmilk. Its amino acid sequence differs from one species to another. This means researchers can even tell what type of milk is being processed when and where.
  Plaque hundreds of years old tells us a lot about the diet of our ancestors.
Plaque hundreds of years old tells us a lot about the diet of our ancestors.

Nothing comes for free
Agriculture brought humans many benefits, but there was also a price to pay for the new lifestyle: the age of infectious diseases began! Large groups lived close together and had contact to pets, but also to parasites like fleas and rats.
Paleogeneticists nowadays are aware of several plague pathogens more than 5000 years old. But where did the disease come from? Were the steppe inhabitants bringing the plague to Central Europe with their horses or did the disease already exist there? That’s difficult to answer. The things is, for the period 5500 to 4800 years ago very few skeletons have been found in Europe – maybe that was because the plague was already rife then and humans were burning their dead? Were the steppe inhabitants migrating into empty spaces? The fact that there is barely any evidence of military conflict between the farmers living in Europe and the herders would support that theory.

The dark side of the revolution
The transition from the hunter-gatherer culture to agriculture and cattle rearing provided favourable conditions for the emergence of new disease pathogens – that’s something researchers have suspected for quite a while. In 2019 they were able to prove it for the first time: in a large-scale analysis of human remains up to 6500 years old, they were able to reconstruct the genome of Salmonella strains several millennia old. The Salmonella found in the bones of the arable farmers and cattle breeders were predecessors of the bacteria strain Paratyphi C – a strain that only infects humans and causes typhoid-type symptoms. The historical Salmonellae on the other hands were probably not that specialised and infected both humans and animals.
  © Mediscan / Alamy Stock Foto
Using Salmonella as an example, researchers were able to prove for the first time that if farmers and animals live closely together it results in the emergence of new diseases.