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This website is aimed at answering fundamental questions we all ask at some point in our lives: "Why am I here?" "Where did I come from?" "Where am I going?" In this website Wyken Seagrave addresses these age-old questions by telling the story which science has discovered about the origin and development of the Universe, Earth, life, mankind, and technology to the present day with a glimpse into the future.

Big History

The study of the history of the Universe is sometimes called "Big History" a discipline established by historian Professor David Christian. It is a subject of growing popularity, offered for study by an increasing number of universities around the world.

Themes of History

A number of themes will emerge as we follow this story. We list the main ones here, with links to more detailed explanations of further links.

Timeline of History

A great way to get an overview of history is from our Timeline of History, one of our most popular pages. It contains a chronological list of the main stages in the history of the Universe. If you prefer a more geological perspective, visit our geological time page.

Note that in this website bya means "billion years ago".

Origin of the Universe

We start this story with the most fundamental questions: When did the universe begin, and HOW? Why can science provide answers to one of these questions but not the other? There are no definite answers about how it began, but there is much speculation. We explore some basic questions and explain one of the most popular theories.


The attraction of electrons to protons was a magic moment early in the history of the Universe. The result was the creation of atoms, a step towards the self-organization of matter which would eventually produce the Earth and people.



The next giant step in history is the formation of the first stars and galaxies. Without stars there would be no planets, and no life, so understanding how they form is important in knowing where we came from.

Milky Way Galaxy

The galaxy in which we live is called the Milky Way, or just "the Galaxy". How big is it? What does it look like, and where are we situated within it? Find out about the wonderful city of stars in which we live.


Stars are the factories where the primitive atoms created in the Big Bang are converted into larger and more interesting atoms which make life possible. And the energy from one star is the main thing which keeps us alive today. So it is fascinating to learn about how they are born, how they work and what happens when they die!


The death of stars is especially important. Dying stars are the places where very heavy atoms are made and then recycled out into the Galaxy to provide the raw materials for planets.


Life as we know it requires that atoms can easily join together and separate again, constantly forming new arrangements called molecules. The mechanism which allows atoms to join in this way is therefore fundamental for the remainder of this story.


Advanced forms of life could never have existed without stable platforms on which to grow and develop. Luckily such places exist in the Universe, and we are finding more and more of them every day. These vital places are the planets.


Our exploration of the Universe has shown that if any other inhabitable planets exist they are so far away that for all practical purposes they are inaccessible. Hence we are totally dependent upon our tiny home planet, and we need to take care of it. So we should understand how it works geologically and what drives its climate.

The Process of Life

From our point of view, the most important event during the Archaean Era (4 to 2.5 bya) was the origin of life. Life almost certainly began in water and probably in the oceans of the Earth. Here we explain how life's fundamental and beautiful chemical system works.

Origin of Life

Now we come to perhaps the second most-asked question in the history of the universe: how did life begin? We examine some of the possibilities and explain the most widely held train of thought.


As we saw above, the earth is a constantly changing theatre. Therefore life would not have lasted very long if it had not been able to change to cope with these changes. The process which allows life to change is called evolution. And, as we explain, the price of this change is the death of some living things.


At the root of life (even today) are the bacteria. Without them we would not be able to digest our food or recycle old dead plants and animals. But as well as providing us with great benefits they can also bring great dangers. So it is sensible that we understand what they are and how they function.

Continental Drift

To us the Earth seems very solid, but in fact the whole planet, including the crust upon which we live, is constantly moving, a changing stage upon which the drama of life will be unfolded. The scene-shifter in this great theatre is called continental drift.

The Great Oxygen Poisoning

Today we are worried about polution from our cities and industries, but in fact the greatest polution event in history occurred 2.4 bya with the release of gas called 'oxygen'. Its result was to change our home planet for ever, and make it possible for us eventually to appear! So what was the cause of this devastating new poison?

Eukaryotic Cells

It was probably during the Paleoproterozoic Era (2.5 to 1.6 bya) that life took the next great leap forward when a totally new and exotic type of cell appeared. It is well that we know about it because our bodies are made entirely of this cell type!


The complex process we call sex provides a very efficient way of generating new cells which can provide the raw material for evolution. Thus its first appearance was the beginning of a rapid improvement in the capabilities of eukaryotic cells.


We saw that blue-green bacteria had learned how to trap the energy of sunlight. Soon eukaryotes learned to do the same, but they took a short-cut to achieve the result!


We saw that bacteria are vital for recycling old dead matter, but they are not alone in this task. Some eukaryotes also learned to exploit the resources left behind by dead cells.

Ice Ages

As well as changing on the inside, the Earth also changed on the outside: the climate was hotter some times than others. Such changes have happened throughout history, and we are in the middle of a dramatic climate change now, so it is good that we understand the causes and possible consequences of this change.

Early Animals

Traces of the oldest definite multicellular organisms with tissues are found in rocks dating from the Ediacaran Period, named after the hills in Australia where the fossils were first found.


Vertebrates first appeared during the Cambrian Period around 500 mya. We regard them as important because we belong to this group.

Plants onto Land

Although known as the Age of Fishes, the Devonian Period saw plants and invertebrates first conquer the land.



Life Escapes from Water

Plants and animals evolved which were able to live without the need to use ponds for reproduction and the great invasion of the land began.


Following a mass extinction of other animals, one group quickly expanded to begin a reign of domination which would last for 150 million years.


While the dinosaurs still dominated, a smaller group of animals evolved with advanced reproduction, but they had to wait for the dinosaur reign to end before they could spread into all ecological niches.

Flowering Plants


Extinction of Dinosaurs

65 mya a disaster happened which eradicated all dinosaurs and opened the door for the diversification of the mammals. Astonishingly, we are still not sure why all the dinosaurs and many other groups of animals and plants became extinct around this time.

Spread of Mammals

Around 50 mya a group of plant eating animals which were ancestors of the horse became common. They spread and evolved into giants, some eating leaves, other grass. The horses, tapirs and rhinoceroses are now the only representatives of this once common group.


Plants were also evolving quickly. Small fruiting plants called grasses, with wind-pollinated flowers and long thin leaves, began to spread. They could live in cooler drier places than other plants, and the climate just happened to be changing in that direction.

Recent Ice Age

The weather grew colder until an ice age started 3 mya. Glaciers spread from the North Pole and from the mountains to cover much of the northern land. With so much water frozen into ice on land, sea level fell and dried out a lot more land than we see today.

Homo Erectus

About 2 mya, Homo habilis evolved into the first people called Homo erectus. Their brains were about twice as large as Homo habilis, their bodies were like ours but their faces were still ape-like.


More advanced people appeared during the last interglacial period of the recent ice age, probably about 600 thousand years ago although the date they first appeared is not well known. They spread throughout Europe, Africa and Asia. Their remains were first found in the Neander Valley, in German called Neander Tal.

Modern Humans

It seems that modern people, Homo sapiens, appeared in Africa about 200 thousand years ago (although the date is far from clear) and lived there while the Neanderthals were spreading around the world.

Current Interglacial

The weather turned warm 11 thousand years ago and the present interglacial (warm phase of an ice age) began.


Nomads herded sheep, cattle and other animals. They could digest milk and so had better food than other people, for in those days most people lost the enzymes needed to digest milk as they grew up. They also gathered some plants but meat and milk were their main foods.


While the nomads were rampaging around the steppe, people in many parts of the world learnt that the seeds from grasses such as barley, wheat, rice and maize made good food and could be kept and eaten all through the winter.


7000 to 5000 years ago was the warmest time of the inter-glacial, much warmer than now. Plants and villages grew quickly. In Iraq and Egypt, in India and China, there were river valleys which flooded every spring and replaced the minerals of the soil. These valleys stayed fertile for many years. Villages here grew into cities.

Cooling Climate

By 5000 years ago the warmest time of the inter-glacial had passed, and the weather started on its long slide towards the next glacial period.

Mass Migrations of People

The invasions of the nomads led to large movements of many peoples. Often the invading nomads would take up a settled way of life when they found a suitable place.


Many nations built empires: the Sumerians, the Akkadians, the Egyptians, the Babylonians, the Kassites, the Hittites, the Assyrians, the Scythians, the Persians, the Macedonians, the Romans and others.

Middle Ages



Around 550 years ago Constantinople, the capital of Byzantium, fell to the cannons of the Islamic Turks, and many of the Greek websites which had been copied and preserved there for nearly 2000 years found their way into Europe.



Industrial Revolution



In 1776 a revolution in the American colonies led to the first modern democracy. This is a system of government which assumes that people have rights, and that one of these is the right to choose the government by regular, free elections.

World Wars


Nuclear Weapons


United Nations

The horrors done during the two world wars so frightened and appalled the world that the United Nations (known as the UN) was started.


Computers are machines which process information. At the present time most computers are electronic, but much faster optical computers are probably just around the corner.

SWOT Analysis of Present Situation

We have watched the birth, childhood and growth of modern industrial society. Now it is time for us to take stock of ourselves. Who are we, and where are we going? One way to do this is to carry out a SWOT analysis of humanity.

Lessons for the Future

In the following pages I try to use the themes and lessons of history to predict (or at least to make educated guesses about) the future. To some extent, of course, what happens in the future will depend on how well we manage to solve our current problems.


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Professor David Christian.