In this paragraph, we will explain the origin of life on earth. Herewith we will not explain the religious view, but the view of most of the scientists.
According to most of the astro-physicists (men who study space, stars and planets) a piece of primal matter was in the enormous extensive emptiness about 16 billion years ago. This piece of primal matter held the entire universe: all protons, electrons, neutrons and all energy. Long ago this primal matter burst open. This is called the 'Big Bang'. From that moment the primal matter spread out into the emptiness. Groups of stars floated away together. These groups are called galaxies. There are probably hundreds of galaxies. One galaxy consists of thousands of star systems revolving around a common centre. A star system consists of one or two stars surrounded with pieces of matter.
Our solar system is a star system. The sun is a star. Ten big planets are revolving around our sun. Between the planets Mars and Jupiter is a belt of large pieces of matter. These pieces are probably the remnants of a planet that exploded. One of the ten planets is our planet.
The earth was formed about 4,5 billion years ago. 3,5 Billion years ago the earth was a wild piece of rock. The earth already had an atmosphere then, but the composition was different. There was probably a lot of carbon- gas in the atmosphere and no oxygen.
In 1951, the American Miller succeeded to form organic matter out of a mixture of ammonia (NH3), methane (CH4), hydrogen (H2) and water (H2O) by exposing this mixture to an electric current. During the experiments different organic mixtures were formed, among them amino acids and nuclein acids. These acids are essential for the building of proteins and chromosomes.
It is possible that these circumstances also occurred in the past. In the primal atmosphere, which was cooling down, the composition of matter was probably the same as in Miller's experiments.
Through lightning organic connections were formed and fell into the prehistoric seas. Through evaporation of the inside seas, concentration might have occurred, giving rise to organic "primal soup". In this primal soup first bigger molecules were formed and later the first forms of life. This origin of life out of lifeless matter is called biogenesis.
About 3,5 billion years ago the first one-celled life forms were formed. These could do photosynthesis: that is they used carbonic oxide and water to make proteins, fats and other organic connections. This transformation costs energy, which they would get from the sunlight. Organisms like this still exist. Algae, plants and trees can do photosynthesis too. The chemistry of this transformation looks like this: 6 parts of CO2 (Carbonic oxide) + 5 parts of H2O water) are transformed with help of sunlight into: 1 part of C6H10O5 (farina) + 6 parts of O2 (oxygen).
In that period of time the atmosphere existed mainly of carbonic oxide with little oxygen. That mixture changed very fast. Because of the composition of the atmosphere, the one-celled life forms multiplied very fast. They had no enemies. The one-celled life forms transformed large amounts of carbonic oxide into oxygen. Since there were no animals to use this oxygen the amount of oxygen in the atmosphere rose very fast, while the amount of carbonic oxide decreased. The atmosphere thus transformed radically. The one-celled life forms originated in a carbonic oxide rich atmosphere, but now it became oxygen rich and carbonic oxide poor. This gave rise to a transformation of the one-celled life forms. A number of these one-celled transformed from oxygen producers (plants) into carbonic oxide producers (animals). They preyed on the old one-celled life forms and digesting them with help of oxygen. Herewith carbonic oxide came free.
After a while a new balance was reached. When there were a lot of oxygen producers (plants), they formed a lot of food for the oxygen consumers (animals). So the number of animals could rise. Then after a while the amount of food would not be enough for the larger numbers of animals and animals would die because of lack of food. Then the number of plants could increase again and so on till now.
Some animals learned that they could also eat other animals. This made the food-circle even more complicated. More and more different species of one-celled life forms arrised. Some survived by eating plants, others by eating animals. The one-celled life forms, which were eaten, did not like that. Some began to resist. Some swam away, others learned to defend themselves or again others to hide themselves. The species that did not resist became extinct. So more spaces came free for the surviving species.
The one-celled hunters had to adapt. In the beginning, the other one-celled life forms were easy preys, but later they could escape more often from the hunters. The hunters, that did not adapt, became extinct. The ones that did adapt to their preys got more food and multiplied faster. The slow one-celled life forms (hunters and preys) became extinct. Between the surviving plants and animals a race of arms arose. Some developed a little bit different from others and survived. For example animals that could hide themselves better by adopting a protective colouring had a better chance of surviving. In the next 3 billion years, the one-celled life forms developed in plants, molluscs, insects and fishes. Some animals were specialised plant-eater, others developed in beasts of prey.
After that, the evolution progressed faster and faster. Animals and plants transformed easier and easier and became more intelligent constantly. 400 Million years ago, fishes became numerous. 300 Million years ago, the first reptiles and amphibians appeared.
The first amphibians and reptiles lead an easy life. They were (after the insects and molluscs) the first animals, which could life on land. The land was full of ferns and other primitive plants, so there was plenty of food. Furthermore there were no enemies jet, but these arrived soon. Reptiles and amphibians began to eat each other. Some reptiles were plant eaters, other real beasts of prey.
245 Million years ago, the first dinosaurs appeared. The dinosaurs dominated the earth till 65 million years ago. At that moment a comet or meteorite shower plausibly struck the earth and changed the temperature radically, so that the big dinosaurs became extinct, because they were not able to adapt. Small animals in the sea and on land had a better chance. They survived the disaster. Not long before this disaster, the first mammalian and birds appeared. They were warm-blooded and were a better match for changes in climate. They survived the cold temperatures.
In the period of 65 up to 3 million years ago the mammalians and birds were the dominating species. Different species learned to use tools. Not only the primates (apish), but also otters. A number of primates were very successful. The man, chimpanzees, gorilla's and orang oetans are descended from them.