According to the theory of evolution, all the animals and plants that exist in the world today are descended from those primitive organisms that inhabited the earth millions of years ago.Improvement of living beings may be due to different processes.This idioadaptation, and degeneration, and aromorphosis.Idioadaptatsy - one of the main directions of evolution, thanks to her body adapts to a particular environment, while not fundamentally altering the structure.The degeneration involves the disappearance of any of the bodies in the process of evolution.It is possible to observe the formation of rudiments, ie residues of which the ancestors performed important functions.The man is, for example, the semilunar fold in the inner corner of the eye, the coccyx, and so on. D. In this direction of evolution as aromorphosis, in this article we will discuss in more detail.
What is it?
Aromorphosis - a complication of the structure of the organism in the course of evolution to improve his life.This could include, for example, the occurrence of sexual reproduction, multicellular, warm-blooded, double fertilization in plants, and so on. D. Due to this process, formed such a diverse biosphere of the planet Earth.
origin of life and the first aromorphoses
Billions of years ago, life began in the ocean, and the first organisms on the planet were single-celled prokaryotes.They had a primitive cell structure did not have in their composition of the nucleus and many organelles, which are eukaryotes.Era, during which there were these first organisms called Archean.It covers the period from 4 to 2.5 billion years ago.During the Archean era, Earth was still not such as we see it now in the atmosphere has almost no oxygen, there was only one continent on land was not yet life, the gaseous envelope of the planet was more dense, and therefore to the surfaceIt fell a little sunshine.
Throughout this era already appeared the first cyanobacteria, like single-celled algae that will inhabit the Earth later, but they were still prokaryotes.But these organisms were not heterotrophs as the first bacteria inhabiting the planet, and autotrophs, they were capable of solar energy, carbon dioxide and water to synthesize their own nutrients.It can be said that the emergence of photosynthesis - it aromorphosis, which provided the impetus for the further development of life on Earth.Due to the fact that organisms have started to use this process to produce organic substances, the atmosphere became progressively enriched with oxygen.
emergence and development of plants
can say that the first plants were cyanobacteria formed in the Archean period, as they were capable of photosynthesis.Further development of the kingdom involves the formation of organisms that consist not of a single cell.The emergence of multicellular organisms - is aromorphosis, which, along with the emergence of photosynthesis is a list of the most important.With this change made possible the development of living things, the formation of the major kingdoms that exist to this day.Red and green algae have been widely distributed throughout the Proterozoic era to the end of the Ordovician period of the Paleozoic era, they were the only plants growing on Earth.
landfall first organisms
The Silurian period, there was a major aromorphosis plants - is the emergence of the first spore, Rhyniophyta.This phenomenon can be regarded as extremely important, as these organisms have entered the land they might dwell on land and in shallow water.
They are also, in fact, were the first plants, the body which has been presented to escape, rather than thallus like algae.410 million years ago Rhyniophyta already mastered land and widely spread on the territory of the planet.In the same period, the Silurian, thanks to plants in an atmosphere already was enough oxygen for the existence of the first land animals.The next most important aromorphosis - is the emergence of the plants instead of seeds of the dispute.So there were gymnosperms.Aromorphosis - is the appearance of the flower and the fruit, the formation of angiosperms.
first aromorphoses animals
parallel with the development of the vegetable kingdom was not in place and the evolution of the animal world.The earliest aromorphosis - is the emergence of two germinal sheets and radial symmetry in multicellular animals.So formed coelenterates, which include corals, sponges, jellyfish, and so on. D.
first animals on land
Then organisms appeared the third embryonic leaf - mesoderm, and the bilateral symmetry of the body, formed muscle tissue, nervous and excretory systems.All these characteristics of types such as flat and segmented worms, which became the next stage of the evolution of animals.At first they lived in the water, and then became the first animal to make landfall.For further aromorphoses include the formation of the two-chamber, three-chamber, and then the four-chambered heart, double circulation, the occurrence of such organs as the kidneys.Another major aromorphosis is the appearance of the chord and further education throughout the spine and musculoskeletal system.
warm-blooded - it aromorphosis, which is also one of the most important in the history of evolution.He served as an impetus to further development in the world of birds and mammals.The first animals that had a warm-blooded, there were some dinosaurs that existed from the beginning of the Triassic period of the Mesozoic era, and the first bird-like animal - Archaeopteryx.This creature had been such a change, as the appearance of feathers, beak, peculiar to birds.Then there was the formation of hair, placenta from other animal species - so there were mammals.As a result listed in this article have any aromorphoses all currently existing types and classes of animals.