The evolution of vegetation: what did the most ancient plants look like? The most ancient plants on Earth: the diversity of the flora of the past

With the reproduction of blue-green algae, also called cyanobacteria, the oxygen content in the air gradually increased. It probably killed a lot of bacteria at first, but over time they...

With the reproduction of blue-green algae, also called cyanobacteria, the oxygen content in the air gradually increased. Probably at first it destroyed a lot of bacteria, but over time they learned to use it in their needs. Development different types bacteria led to the emergence of other types of organisms that obtained energy simply by eating more primitive relatives. Next milestone began when more complex cells acquired the ability to photosynthesize due to the appearance of the chloroplast. These were the first true plant cells.

plant evolution

The first plants were single-celled organisms that arose when blue-green algae took refuge in large cells. These large cells already had mitochondria that came from other bacteria. In the "look" of cells, giving shelter to bacteria, they receive a lot of advantages - mitochondria helped them use oxygen, and chloroplasts produced food for them.

These progenitors of plants, obviously, lived on the surface of the seas and lakes, as now there are their numerous descendants - unicellular algae. Over time, unicellular plants developed into multicellular plants when their cells remained together after division. Some formed balls from cells, others - empty cylinders, chains of cells. Many organisms with such adaptations still live in the form of algae.

Way to land

For millions of years, the only form of plant life on Earth was algae. As now, they existed practically only in water, because they dried up on the ground. Then small algae began to grow on the shores of lakes, near the water itself. Over time, they developed semi-waterproof shells and root-like structures that sucked moisture from the soil.

These pioneer algae gave rise to mosses, primitive plants that also only survive in damp places. Over time, more developed plants appeared, like ferns, with leaves covered with a waterproof shell. They were the first to develop roots and woody stems, which allowed them to grow upwards.

When did the first plants appear on Earth?

Scientists believe that the first plants on Earth appeared with the beginning of the process of photosynthesis, which took place in bacteria. This important process of interaction between fluid and sunlight became a source of free oxygen. Thanks to this, the plant world was born.

First plants

Often people wonder what species were the first and how they appeared on our planet. Scientists have answered. The first representatives of the flora that managed to appear on earth were rhinia and cooksonia. The latter looked like a small bush, the size of which did not exceed 5-7 cm. favorable conditions for the development of kuksonia, a swampy area possessed. Traces of the presence of this cooksonia were found on the territory of the Czech Republic, the USA and Western Siberia. Rinia is a plant similar to cooksonia. Despite the relationship of origin, the size of rhinia was more significant - up to 50 cm in height. Initially, each of the plants had only 1 species.

According to another version, one of the first on earth was the moss that appeared. In addition, the remains of unicellular algae and fungi were found. Swampy and shady areas are also considered to be their places of origin.

Appearance time

There is no single answer to the question of when plants appeared on earth. Each of the representatives of the earth's flora began to appear at a certain time:

• the first unicellular (mosses, lichens) - 2 billion years ago;
• more complex plants (similar to modern ferns) - 4 million years;
• conifers and pines appeared about 3 million years ago;
• the age of the first flowering plants is 150 million years.

Ferns are one of the first full-fledged representatives of the flora, having a root, stem and leaves. Until now, they grow in swampy areas. By the time the dinosaurs settled the planet, its surface was already inhabited by mosses, grasses, shrubs and trees. The first coniferous trees include pine, spruce, larch and cedar. Seeds of flowering representatives, in comparison with others, had greater protection. This explains the variety of colors.

Over time, climate change and changing development conditions, grasses and trees have evolved. Now too many varieties of shrubs, flowers and trees are artificially bred. In order to visualize those plants that prevailed on our planet millions of years ago, you need to look at the ferns and grasses that grow in swamps and forests. They can be considered direct descendants of ancient mosses and ferns.

Without plants, our planet would be a lifeless desert. And the leaves of trees are small factories or chemical laboratories, where substances are transformed under the influence of sunlight and heat. Trees not only improve the composition of the air and soften its temperature. The forest has medicinal value, it also provides most of our needs for food, as well as for materials such as wood and cotton; they are also raw materials for the production of medicines.

I. What were the very first plants on earth?

Life on Earth began in the sea. Plants were the first to appear on our planet. Many of them got out on land and became completely different. But those that remained at sea remained almost unchanged. They are the most ancient ones, everything started with them. Without plants, life on Earth would not be possible. Only plants can absorb carbon dioxide and release oxygen. For this they use Sun rays. Algae were among the first plants on earth.

More than 20,000 species of algae are known. They can be fixed on rocks or on seabed with the help of a foot-like "bracket" that passes into a branch with sheets. Brown algae grow in cold waters and reach enormous sizes. Red algae are characteristic of warm seas. Green and blue-green algae can be found in both warm and cold waters. From brown algae get a lot useful substances used in the manufacture of plastics, varnishes, paints, paper and even explosives. They are used to make medicines, fertilizer, and feed for livestock. Among the peoples of Southeast Asia, algae are the basis of many dishes.

Algae "Floating forest".

In the old days, there were legends about the Sargasso Sea, where ships died, stuck in algae. But still, in some places the thickets of algae are so dense that they can delay a light boat. These are brown algae-sargasso, after which the sea itself is named. Sargassums look like bushes dotted with "berries" - air bubbles that allow the plant to stay on the surface of the water. Unlike other large algae, sargasso do not attach to the bottom and travel in huge clusters along the waves and form a floating forest. A myriad of molluscs, worms, and bryozoans attach themselves to the leaves of the sargassum, and crabs, shrimps, and fish hide in its thickets. Almost all the "residents" are brownish-yellow in color, in the tone of sargasso, and their bodies often copy the shape of the "leaves" of this algae. Some are hiding so as not to frighten off the victim. So this whole community swims, never touching the shore.

II. They feed, clothe, delight.

1. Trees that provide food.

Coffee is one of the most popular drinks in the world.

Who and how gave us this wonderful drink? According to an old Arab legend, we are obliged to find coffee. goats. One Ethiopian shepherd, the legend says, noticed that his goats, having eaten some berries from a bush, continued to graze all night, not thinking of resting. The shepherd told the wise old man about this, and he, having tasted these berries, discovered their miraculous power and invented the coffee drink.

The Ethiopians liked coffee so much that later one of the tribes, having moved to the Arabian Peninsula, took its grains with them. That was the first start coffee plantations. And it happened, as is known from ancient manuscripts, in the 9th century. Coffee for a long time was known only to the Arabs, but the Turks, who conquered in the XV-XVI centuries. part of the Arab territories, also appreciated the taste and wonderful properties of the drink. This is how the famous method of making Turkish coffee appeared: coffee is brewed on hot sand in special copper vessels with a handle - “Turks”.

Europeans were first introduced to coffee by an Italian who returned from Turkey. A doctor by profession, he recommended that his patients drink coffee for medicinal purposes. Venice was the first to import coffee to Europe. And in 1652 the first coffee house was opened in England. Turkey was the monopoly supplier of coffee to Europe, but the cunning Dutch, having stolen seedlings of coffee trees from the Turks, transported them to Indonesia, where the climate was quite suitable for growing coffee. Brazil is now the world leader in coffee production.

Coffee came to Russia thanks to Peter the Great.

Coffee drink is brewed from processed seeds coffee tree. This evergreen from the madder family. White lush inflorescences of the coffee tree, located in the axils of the leaves, after pollination by insects, turn into fruits - red berries remove the pulp from them, the seeds are polished in special drums and packed in bags. Before brewing coffee beans fry.

The birthplace of coffee is Africa. The Arabian species is considered the highest quality and most delicious. Brazilian coffee (this is not a species, but only a place where coffee is grown), which fills all the markets of the world, is much worse in quality than coffee grown in other countries.

2. Noble friends.

Cedruses are real cedars. Phoenicia, Egypt, Assyria were powerful powers of antiquity. But the territories they occupied were deserted, there were almost no forests there. And wood is needed for the construction of housing, and for ships. The wood is strong and does not rot. The cedar that the ancients loved is not the cedar that grows in the taiga and is famous for its delicious nuts. Siberian pines are "namesakes" of real cedars - cedrus.

The Phoenicians cut Cedruses into ships, the Egyptians into sarcophagi for the funeral ceremonies of their nobles, the Greeks and Romans used cedar to build temples and make furniture. Later, the crusaders began to cut down the cedrus. And during the First World War, the most valuable cedars with their pink wood, for lack of other fuel, were burned in locomotive fireboxes. So there are only 4 groves of Lebanese cedars left. True, other types of cedar - Atlas, Cypriot and Himalayan, although very rare trees, but, unlike the Lebanese cedar, are still not disappearing.

Lebanese cedars are majestic trees with powerful horizontal branches. Their needles are bluish, collected in tassels. Fist-sized buds, dense, almost smooth, like barrels. When the seeds ripen in them, the cones do not open, but crumble, and the earth is covered with a layer of scales. The wind blows off the winged seeds from them and spreads them around. If the goats, which are bred in abundance by the locals, do not eat the young shoots, a new generation of handsome cedars may grow out of them. The fame of the beauty of the Lebanese cedars has also reached Russia. Therefore, when the Russian pioneers saw Siberian pines, tall, majestic, with large cones, they called them cedars.

Siberian cedar is an amazing pine. The main wealth of the cedar is its nuts. They contain fats, proteins, starch, vitamins B and D, and the needles contain many healing substances. Nuts contain more than 60% oil, which in many ways surpasses animal fats and is not inferior in nutritional value to meat and eggs. Under Ivan the Terrible, these nuts were exported abroad, and under Peter I, they began to prepare a healing and strengthening remedy in Russia - nut milk.

Pine nuts play a huge role in the life of animals. “Where there is no cedar,” the hunters say, “there is no sable.” Bears and chipmunks, squirrels and various birds eat nuts.

Healing and cedar resin - resin. During the years of the Great Patriotic War cedar balm saved from wounds and burns. Resin is a necessary raw material for obtaining such a valuable medicine as camphor. Resin is also needed in optical technology.

Cedar wood is also valuable - pencil sticks are made from it, musical instruments, make furniture. Turpentine and other useful products are obtained from sawdust.

III. The study of the bark of a tree.

Norway maple

The maple I was watching is young. It has a tree trunk, which thickens every year, side branches form a crown, which consists of smaller branches, leaves. The tree is held in the soil by roots that absorb moisture and minerals dissolved in it. Therefore, the bottom of the tree trunk is wider.

If you smell the bark, then the smell is bitter, astringent. In spring, the smell of the bark intensifies and becomes sweetish.

There is no hollow in my tree. But I met trees with a hollow. Various birds make their homes in the hollow.

There are no lichens, mosses and mushrooms on the maple that I observe. Sometimes fungi form mushroom roots on the roots, supplying the trees with nitrogen and minerals.

On the bark of my tree there are traces left by a man: peeled bark and scratches from a knife, which over time it could heal.

IV. Why is my friend the best.

Norway maple - branch with fruits

Maple is one of the most elegant trees growing in our forests. In the spring, when the branches of the trees are not yet covered with leaves, the maple blossoms. Its yellow-green flowers, collected in an inflorescence, delight the eye. Maple is no less elegant in summer, when its crown becomes “curly”. Autumn outfit will not yield in beauty to any other plant. The tree seems to be on fire, striking with the richness of shades of crimson and green, orange and yellow. Each leaf has its own color, and each leaf is beautiful in its own way. And everyone has the same shape: rounded with 5-7 sharp protrusions, hence the name Norway maple. Maple is a good honey plant. Up to 10 kg of honey is obtained from one tree. Maple juice is very tasty. In Russia, kvass and various soft drinks were prepared from it.

The flag of Canada features a leaf of the Sugar Maple. Its sweet juice was used to make maple syrups, molasses, and even maple beer, which was very popular in the 19th century. Canada was the leader in the production of juice products. The maple leaf has become the national symbol of this country.

From maple wood - strong and easy to make musical instruments. Sports equipment is also made from maple. Pharmacists and chemists use the leaves and bark. Maple has one more interesting property A: He can predict the weather. From the petioles of the leaves, at the very branch, sometimes “tears” flow drop by drop - the maple seems to be crying. This is the property of maple to get rid of excess moisture. And the “tears” of maple depend on whether the air is dry or humid. The drier the air, the stronger the evaporation and vice versa. The air becomes humid when it rains. If they appeared on maple leaves“tears, it means that in a few hours it will rain.

V. Fossil trees that have remained on the earth.

Ancient, ancient ginkgo tree! It appeared on earth as early as the time of the dinosaurs - 125 million years ago. And since then, this plant has not changed much. Ginkgo - beautiful tree up to 30 m high, with large fan-like leaves. The appearance of ginkgo resembles our ordinary aspen. But it was not there! Ginkgo is a gymnosperm, more closely related to spruce than to aspen, a flowering plant. In spring, “earrings” appear on the branches along with foliage. By autumn, large seeds resembling plums hang on the branches. The pulp of the seed, which looks like a fruit, is actually just the seed coat. It is edible and tastes salty. One problem - it smells like rotten meat. This is a way to attract seed dispersal animals. Ginkgo, although it survived the dinosaurs, did not survive in the wild. This tree has become a garden tree. In Japan and China, it is considered sacred - it is grown near temples. Now ginkgo appears on the streets of European cities. Ginkgo easily resists air pollution, diseases, and insects. Ginkgo leaves and wood contain substances that repel insects. Bookmarks from dried ginkgo leaves will protect old manuscripts from bookworms. And the walls covered with ginkgo shingles will not let cockroaches or bedbugs into the house.

CONCLUSION.

What can I do for all trees?

Coming to the forest, I will not kindle fires. This can lead to fires.

I won't destroy bird nests. Birds eat insects that damage trees. I will not break branches from trees and shrubs. I will plant new seedlings in the yard and take care of them in the future.

Acid rain also causes irreparable damage: the death of crops, flora and fauna, the destruction of buildings.

The first representatives of the flora appeared on the planet more than 2 billion years ago, in an era that researchers call Archaea. Consider the most ancient plants on Earth - what they looked like and what role they played in the evolutionary process.

Archean era

This period is separated from us by billions of years, so the data on what living organisms existed at that time are very conditional and often have the character of hypotheses. Scientists have little material for research, since the representatives of this ancient time did not leave any traces behind them. In this geological era, there was no oxygen in the atmosphere, so only those organisms that did not need it could survive. Features of the plant world of the Archean era are as follows:

• The most ancient plants on Earth are considered to be blue-green algae, the fact that they already existed is evidenced by organic substances - marble, limestone.
• Later, colonial algae appeared.
• The next stage in the development of flora is the appearance of photosynthetic organisms. They took in carbon dioxide from the atmosphere and gave off oxygen.

It can be concluded that algae are the most ancient plants of the Earth, their role was more than significant: it was these tiny representatives of the flora that managed to fill the atmosphere with oxygen necessary for life and made it possible for further evolution. Living organisms were able to leave the sea and move to land.

Proterozoic

The next stage in the development of the most ancient plants on Earth is the Proterozoic era, it was then that many varieties of algae originated:

• red;
• brown;
• green.

It was during this era that a clear division of organisms into plants and animals occurred. The former could synthesize oxygen, while the latter did not possess this ability.

Paleozoic

The most ancient plants on Earth are seaweeds, it is to them that we owe the appearance of the atmosphere, oxygenated. They made our world habitable. In the first two periods of the Paleozoic, the flora was represented exclusively by algae, but other plants gradually appeared:

• During the Silurian period, spore plants. Soil appeared, so they could grow on land.
• Rhinophytes, the simplest representatives of the fauna, arose in Delour.
• Then there are club mosses and great-ferns, gymnosperms.
• During the Carboniferous, horsetail-like, ferns are born.

The first forests of huge horsetails, ferns and club mosses appear on the planet. In the Carboniferous period, club mosses and calamites reach their peak, which often towered 30-40 meters above the ground. Gradually dying off, these plants formed reserves of coal, which mankind uses to this day. The most ancient plants on Earth played essential role, giving us a valuable mineral. Without coal, the development of industry would not have been possible.

In the Permian period, some coniferous species are formed.

Exit of plants to land: features of the process

The most ancient plants on Earth that left the water element and moved to land, as researchers believe, were algae and lichens. They did not leave any traces behind them, and conclusions about their existence are made only by indirect signs:

• The formation of rocks. This process is possible only with the participation of living organisms.
• The process of soil formation in water could not go on - this indicates that the plants have already climbed to the surface of the earth.
• Now fossil-like algae are found on land in the form of plaque on stones and tree bark, in conditions of increased importance. Therefore, the researchers suggest that in ancient periods they could also adapt to life outside the sea.

In the later periods of the Paleozoic, land plants which have not reached our days. Only their petrified spores have survived. They are very similar to the spores of liverworts, modern plants related to mosses. It can be concluded that the most ancient plants on Earth are mosses, while horsetails "came" out of the sea and settled on land during the Late Paleozoic.

First forests

The first representatives of the flora preferred to settle in damp places, so fern forests were often buried in water. The oldest forests were shallow water bodies, similar to swamps, but devoid of a peat layer. It was here that giant ferns grew. Such an ecosystem is often referred to as a forest-reservoir.

First gymnosperms

The most ancient plants on Earth reproduced by spores, which were very vulnerable and could die in adverse environmental conditions. Therefore, the appearance of gymnosperms was the most important step on the path of evolution. Seeds had a number of advantages over spores:

• they had a nutrient supply;
• could survive adverse conditions;
• not afraid of exposure to UV rays and drying;

Mesozoic

At this time, the most important processes take place:

• formation of continents;
• the birth of lakes and seas;
• climate change.

The plant world is also undergoing significant changes: giant ferns and club mosses are dying out, and gymnosperms of coniferous trees are spreading. Plant imprints with angiosperm-like features have been found in beds from the early Cretaceous and Jurassic. These were primitive and few forms. Angiosperms became widespread in the Middle Cretaceous, about a hundred million years ago. However, by the end of the period, they had become the dominant form of plant life on Earth. The plant world became more and more similar to what we are used to.

Features of the flora of the Mesozoic era are as follows:

• The appearance of vessels in plants, the functions of which were to conduct water and nutrients.
• A reproductive organ is formed - a flower. Through pollination by insects flowering plants quickly spread across the continents.
• The predecessors of modern cypresses and pines appear.

We examined which plants are the most ancient on Earth, traced the main paths of the evolutionary development of flora over geological epochs. Despite the fact that the first algae did not leave any traces behind them, their role is enormous: they were able to fill the atmosphere of the planet with oxygen and made possible way out living organisms on land.

Our planet has not always been green. A long time ago, when life was just emerging, the land was empty and lifeless - the first forms chose the oceans as their habitat. But gradually the earth's surface also began to be mastered by various creatures. The first plants on Earth are also the earliest inhabitants of land. What were the ancestors of modern representatives of the flora?

So, imagine the Earth 420 million years ago, in an era called the Silurian period. This date was not chosen by chance - it was at this time, scientists believe, that plants finally began to conquer the land.

For the first time, the remains of cooksonia were discovered in Scotland (the first representative of the terrestrial flora was named after Isabella Cookson, a famous paleobotanist). But scientists suggest that it was distributed throughout the globe.

It was not so easy to get out of the waters of the oceans and start developing the land. To do this, the plants had to literally rebuild the entire body: to acquire a shell resembling a cuticle that prevents drying out, and to acquire special stomata, with which it was possible to regulate evaporation and absorb substances necessary for life.

Cooksonia, which is a thin green stems, not exceeding five centimeters in height, was considered one of the most developed plants. But the atmosphere of the Earth and its inhabitants were rapidly changing, and the most ancient representative of the flora was losing ground more and more. On this moment the plant is considered extinct.

The remains of the nematothallus do not even remotely resemble plants - they look more like shapeless black spots. But despite the strange appearance, in terms of development, this plant has gone far ahead of its comrades in its habitat. The fact is that the cuticle of the nematothallus is already more similar to the parts of existing plants - it consisted of formations resembling modern cells, which is why it was called pseudocellular. It should be noted that in other species this shell looked just like a continuous film.

Nematothallus has given a lot of food for thought to the scientific world. Some scientists attributed it to red algae, others were inclined to believe that they had a lichen in front of them. And until now, the mystery of this ancient organism has not been solved.

Rinia and almost all other ancient plants with a vascular structure are classified as rhinophytes. Representatives of this group have not grown on Earth for a long time. However given fact does not at all prevent scientists from studying these living creatures that once dominated the land - a lot of fossils found in many parts of the world make it possible to judge both the appearance and the structure of such plants.

Rhyniophytes have several important features, which allow us to assert that these living beings are completely different from their descendants. First, their stem was not covered with soft bark: scaly processes grew on it. Secondly, rhinophytes reproduced exclusively with the help of spores, which were formed in special organs called sporangia.

But the most important difference is that these plants did not have a root system as such. Instead, there were root formations covered with "hairs" - rhizoids, with the help of which rhinia absorbed water and substances necessary for life.

This plant was recently considered a representative of the animal world. The fact is that its remains - small, rounded in shape - were originally mistaken for eggs of frogs or fish, algae, or even eggs of long-extinct crustacean scorpions. The spores of the parka, found in 1891, put an end to the misconceptions.

The plant lived on our planet about 400 million years ago. This time refers to the beginning of the Devonian period.

The remains of pahiteki, as well as the fossils found parka, are balls small size(the largest one found has a diameter of 7 millimeters). Quite little is known about this plant: scientists managed to establish only the fact that it consisted of tubules located radially and converging in the center where the nucleus was located.

This plant is a dead end branch of the development of flora, in fact, like parks and rhinia. It was not possible to establish for certain what was the impetus for their emergence, and why they died out. The only reason, according to scientists, is the development of vascular plants, which simply replaced their less developed relatives.

The plants that got out on land chose a completely different path of development. It was thanks to them that the animal world was born and, accordingly, a reasonable form of life appeared - man. And who knows what our planet would look like now if the rhinii, parkas and cooksonia had not decided to explore the land? ..

That's all we have. We are very glad that you have looked at our site and spent some time enriching yourself with new knowledge.

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400 million years ago, a huge part of the earth's surface of our planet was occupied by seas and oceans. The first living organisms arose in the aquatic environment. They were pieces of slime. After several million years, these primitive microorganisms developed a green color. By appearance they began to look like algae.

Plants in the Carboniferous

Climatic conditions favorably influenced the growth and reproduction of algae. Over time, the surface of the earth and the bottom of the oceans were subjected to changes. New continents arose, while the old ones disappeared under water. The earth's crust was actively changing. These processes led to the fact that water appeared on the site of the earth's surface.

Retreating, sea water fell into crevices, depressions. They then dried up, then again filled with water. As a result, those algae that were on the seabed gradually moved to the earth's surface. But since the drying process was very slow, during this time they adapted to the new living conditions on earth. This process has been going on for millions of years.

The climate at that time was very humid and warm. He contributed to the transition of plants from marine to terrestrial life. Evolution led to the complication of the structure of various plants, and ancient algae also changed. They gave rise to the development of new terrestrial plants - psilophytes. In appearance, they resembled small plants that were located near the banks of river lakes. They had a stem that was covered with small bristles. But, like algae, psilophytes did not have a root system.

Plants in a new climate

Ferns originated from psilophytes. The psilophytes themselves ceased to exist 300 million years ago.

humid climate and a large number of waters led to the rapid spread of various plants - ferns, horsetails, club mosses. The end of the Carboniferous period was marked by a change in climate: it became drier and colder. Huge ferns began to die out. The remains of dead plants rotted and turned into coal, with which people then heated their homes.

Ferns had seeds on their leaves, which were called gymnosperms. Modern pines, spruces, firs, which are called gymnosperms, originated from giant ferns.

With climate change, ancient ferns have disappeared. The cold climate destroyed their tender shoots. They were replaced by seed ferns, which are called the first gymnosperms. These plants have perfectly adapted to the new conditions of a dry and cold climate. In this plant species, the reproduction process did not depend on the water that is in the external environment.

130 million years ago, various shrubs and herbs arose on Earth, the seeds of which were in the surface of the fruit. They were called angiosperms. For 60 million years, angiosperms have lived on our planet. These plants have remained virtually unchanged from then to the present day.