According to official science, life originated on our planet about three billion years ago in the form of simple organisms - isolated microscopic rods, filamentary structures, spherical and polygonal-celled algae.These organisms can exist only in the water and only in warm climates.
In general, to have survived very few fossils from the Precambrian period.Evolution seems stalled since the dawn of life for three billion years, changing and improving the only existing species of algae and microscopic organisms.
However, 580 million years ago, a turning point in the history of evolution - the Cambrian period.Its duration is within the life of the Earth is small - 80 million years.It was then that suddenly and almost simultaneously there was an amazing variety of species of invertebrates.More importantly - living organisms through a short period of time were able to acquire a solid calcareous skeleton.
Multiple biological forms of the Cambrian was the predecessor of all kinds of modern life, including
Land at the time was an absolute pustnynyu whole life focused only in the water.Earth continents were completely different location: for example, on the site of Greenland and the North American continent was Lavrentsov south was the Brazilian mainland.Arabia, Africa and Madagascar were united African continent, located in the northern Russian mainland, the strait separating the inner from the Siberian and the Chinese mainland.In the south, there was a giant Australian mainland, which later broke up into India, Australia and a number of islands.
formed in the Cambrian period, some modern mountain: Northern Appalachian Mountains, the Sayan Ridge Mountains Chingiztau (Kazakhstan).
in water rapidly blossomed life: trilobites emerged and settled, radiolarians, sponges, brachiopods.There archeocyathids - multicellular animals, which is a cross between corals and sponges.They were attached to the bottom in large bodies of water, forming a kind of coral reefs.By the end of the Cambrian, they became extinct.
At this time flourished especially trilobites - primitive arthropods like modern woodlice.They had a flat disc-shaped body with chitinous armor, divided into 45-50 segments and a plurality of legs.
Toward the end of the Cambrian there were first armored vertebrates, fish prototypes.
So, without any transitional forms and intermediate binding species of bacteria and protozoa in the world suddenly form a plurality of invertebrate and vertebrate species, prototypes of modern forms.The Cambrian is a mysterious evolutionary leap in Earth's history.
Most often scholars attribute this to the revolutionary events of a critical accumulation of oxygen in the ocean air, as well as an increase in flush salts from the land and the increase in the concentration of calcium and magnesium in the water.The chemical composition of the water has changed so much that the organisms living there, got a lot of opportunities for change and the formation of species.
still suggest that at about this time, the Earth has made a sudden coup by almost 90 degrees, which is why there was a dramatic shift of all the continents, tectonic shifts and the formation of modern landforms.It also influenced the formation of new species and adaptations for survival.
Periods of the Earth met a lot of catastrophes: for example, almost simultaneously and without exception the dinosaurs disappeared 65 million years ago.And in the Permian era in a short period became extinct at the same time almost 95% of marine life - it was 245 million years ago.
But among all these mysteries only the Cambrian period differs its creative rather than the destruction of the species.Opponents of evolutionary approach see in the puzzle Cambrian explosion proof divine origin of modern forms of life, including humans.