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We love plants, but seldom stop a while to think and ponder about their history: plants, like animals, originated in ancient seas. Fossil records as well as interpretative reconstructions provide us with some basis for understanding how plants came out of the water and disseminated thorough land.

It is assumed that this was a gradual process, but steady enough to provide plants with all systems and adaptations needed to live outside water, which was no small problem for them indeed. We just have to consider that going from a wet into a relatively dry environment where gravity takes a higher toll requires internal as well as external adaptations which are pretty significant: first, plants needed to develop a protective outer layer to hamper evaporation.

As long as the loss of water was a problem, plants could not grow far from abundant water. Then, since gravity on land affects any organism more than in the water, plants had to develop a whole new vascular and capillary system. The change of habitats took place almost side by side with that of the animals, but before the first amphibians like 'Ichtyostega' - the first tetrapod yet identified, that is, animal on all fours - first roamed the primitive continents, scorpions began conquering the land, and these were big ones: the Eurypterids reached a length of almost 2,5 metres.

Most certainly, these fed either from marine life, or from the first plants; they adapted to terrestrial life, albeit their arthropod exoskeletons proved inefficient for such bulky animals outside water so only smaller scorpions remained to our days, but we can still find them in rather big numbers. The first terrestrial plants did not have advance reproduction systems, neither they had to compete for space or sunlight.

They were pretty rudimentary and the first that we know of consisted simply on a base that attached to the ground and from which something like spines sprouted out; there were no leaves. That came after, and allowed for better adaptation to different environmental conditions and habitats.

Shortly after, during the Carboniferous period, about 360 to 286 million years ago, the world was already covered with spectacular vegetal forms. Plant evolution has in no way stopped: flowers appeared shortly after dinosaurs got extinct.

They began to populate our planet during the Palaeocene period, about 66,4 to 57,8 million years ago, and increased significantly the oxygen levels in our atmosphere. Curiously enough, oxygen is a toxic substance, and another form of combination of oxygen atoms, the ozone, is highly toxic and after fluoride, the single most violent chemical reagent in existence.

However, oxygen provides us with life, and ozone protects us from direct sun radiation which is in fact, deadly. So, without the help of plants, starting aeons before they ever ventured outside oceans now lost in the night of time, life as we know it would never have been possible.

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