Aromorphosis is what?

According to the theory of evolution, all the animals and plants that exist in the modern world have descended from those primitive organisms that inhabited the Earth millions of years ago. Improvement of living beings can occur due to various processes. This is idioadaptation, and degeneration, and aromorphosis. Idioadaptation is one of the main directions of evolution, thanks to it the organism adapts to a specific habitat, while not changing its structure radically. Degeneration involves the disappearance of some organs in the process of evolution. In this case, one can observe the formation of rudiments, that is, remnants of organs, which in the ancestors performed important functions. In humans it is, for example, a half-moon fold in the inner corner of the eye, a coccyx, etc. In this direction of evolution, like aromorphosis, in this article we will dwell in more detail.

What it is?

Aromorphosis is a complication of the structure of the organism in the course of evolution to enhance its vital activity. This includes, for example, the emergence of sexual reproduction, multicellularity, warm-bloodedness, double fertilization in plants, etc. Thanks to this process, so diverse a biosphere of the planet Earth was formed.

The origin of life and the first aromorphosis

Billions of years ago in the ocean life began, and the first organisms on the planet were unicellular prokaryotes. Their cells had a primitive structure, they did not have the core and many organelles that eukaryotes have. The era during which these first organisms existed is called the Archaean. It covers the period from 4 to 2.5 billion years ago. During the Archaean Era, the Earth was still quite different from what we see today: there was almost no oxygen in the atmosphere, only one continent existed, there was still no life on land, the gas shell of the planet was denser, and therefore the surface There was little sunlight.

During this era, the first cyanobacteria, like single-celled algae, would appear , which will later inhabit the Earth, but they were still prokaryotes. But these organisms were no longer heterotrophs, as the first bacteria inhabiting the planet, and autotrophs, they were able to synthesize nutrients independently from solar energy, carbon dioxide and water. We can say that the emergence of photosynthesis is an aromorphosis, which served as an impetus for the further development of life on Earth. Due to the fact that organisms began to use this process to produce organic substances, the atmosphere gradually became enriched with oxygen.

The emergence and development of plants

We can say that the first plants were cyanobacteria, formed in the Archean period, since they were already capable of photosynthesis. Further development of this kingdom implies the formation of organisms that consisted not of a single cell. The emergence of multicellularity is an aromorphosis, which, along with the appearance of photosynthesis, is on the list of the most important. Thanks to this change, it became possible to develop living beings, the formation of the main kingdoms that exist to this day. Red and green algae were widespread throughout the Proterozoic era, until the end of the Ordovician period of the Paleozoic era, they were the only plants that lived on Earth.

Exit to the land of the first organisms

In the Silurian period there was an important aromorphosis in plants - this is the origin of the first sporic, rhinophytes. This phenomenon can be considered extremely significant, since these organisms have already reached the land: they could live on land as well as in shallow water.

They also, in fact, were the first plants whose body was represented by an escape, and not by a thallus, as in algae. 410 million years ago the rhinophytes have already mastered the land and have spread widely around the planet. In the same period, the Silurian, thanks to the plants in the atmosphere, there was already enough oxygen for the existence of the first terrestrial animals. The next most important aromorphosis is the appearance of seeds in plants instead of spores. So the gymnosperm appeared. Aromorphosis is the appearance of the flower and fetus, the formation of angiosperms.

The first aromorphosis of animals

In parallel with the development of the vegetable kingdom, the evolution of the animal kingdom did not stand in place. The earliest aromorphosis is the appearance of two embryonic sheets and radial symmetry in multicellular animals. So coelenterates were formed, which include coral polyps, sponges, jellyfish, etc.

The first animals on land

Then the third germinal leaf appeared - the mesoderm, as well as bilateral symmetry of the body, muscle tissues, nervous and excretory systems were formed. All these are characteristic features of such types as flat and annel worms, which have become the next step in the evolution of animals. First they lived in water, and then they became the first animals to come out on land. Further aromorphosis can include the formation of a two-chamber, three-chamber, and then a four-chambered heart, two circles of blood circulation, the emergence of organs such as the kidneys. Another major aromorphosis is the appearance of the chord and the further formation of the spine and the entire musculoskeletal system.

Warmth-keeping is an aromorphosis, which is also one of the most important in the history of evolution. He served as a stimulus to the further development of birds and mammals on Earth. The first animals that were warm-blooded were some dinosaurs that existed since the early Triassic period of the Mesozoic era, and the first bird-like animal, Archeopteryx. This creature already had such changes as the appearance of feathers, beak, peculiar to birds. Further formation of wool, placenta in other species of the fauna - so appeared mammals. As a result of the aromorphoses listed in this article, all types and classes of animals that have existed to date have emerged.