Our earliest thoughts when we think of primitive humans that have roamed this land of ours for thousands of years. Is one of people, clothed in animal skins, with spear in hand, trekking across this land of ours, in search of food!
Ice Ages, have affected this land of ours, with deep sheets of ice, and have been here, long before the first human made his or her appearance.
The “Ice Age” that affected Britain, saw the Earth’s surface and atmosphere drop in temperature, and the polar ice sheets expand outwards from the north and south poles. This caused much of Earth’s water to become trapped in ice sheets.
During this period Britain was joined with Ireland and Europe. The connection with Ireland dissipated by 14,000 BC and with Europe around 5,600 BC.
When the Ice Age came to an end, the ice would slowly melt, and the oceans would return, and the sea levels would rise. Coastlines would change, and so much of the coastal outlines would change, with the creation of new water areas, when before there was none. Britain was connected to Europe by land mass, which has been replaced by the English Channel.
The last Ice Age came to an end in 10,000 BC, and nomads moved to the lands of Britain around 9,600 BC, and by 4,000 BC the island showed signs of a Neolithic culture inhabiting the island.
Planet Earth had received a respite from the Ice Age, but for how long?
If we look back at our history, Planet Earth could be millions of years old, and have been plunged into deep-cold Ice Ages many times over. The warm weather would fade away, only to be replaced by cold weather winter and summer, which would be an indication of the return of an Ice Age.
Mysterious objects of the past is all that remains, offering us a tantalizing glimpse into our past. Ancient life in the form of fossils, embedded into the rock. Fossilization process started when animals and plants died out, and became buried in mud or sand sediment. Water and bacteria within the sediment dissolved dead organisms, and at the same time impregnated hard parts with mineral deposits. Over time a shape formed, a replica made of mineral instead of organic matter. Millions of years passed by and the sediment was drained and compacted with fossilized shapes within, forming solid rock.
Creatures that existed during Earth’s first 4,000 million years since its creation, most are known to have left no trace. Around 5,000 million years BC emerged creatures with a hard skeletal structure, one which did not compose after death. These included vertebrates (animals with a backbone).
Their fossilized record starts with boney fishes, without fins or jaws that wriggled through water, like that of a tadpole, feeding upon plankton in a sucking method. Later species were known to have fins and jaws, possibly the shark which appeared in our waters around 375 million years BC.
From boney, finned fishes developed amphibians, they be the first vertebrates known to walk on this land. Like fish, these creatures had the ability to lay eggs in water, but they differed from fish, for they could live on land and in water as well. They are thought to be the “Crossopterygii” a fish possessed of muscular fins, it is these they used to drag themselves across land, and had lungs to breathe with, for they could take in air directly.
As the years moved forward, amphibians’ progressed in the development of legs and feet, for use on land. Smaller species spent less time in water environments, having been driven inland. So it was, they had scalier skins, laid eggs with coatings, thus protecting embryo’s from desiccation… the first of the reptiles.
The “Seymouria Baylorensis” with its reptilian backbone fused to the pelvis, possessing amphibian characteristics’, including labyrinth teeth and eardrums at 80 centimetres in length.
On the other hand we have the “Brachiosaurus” a 25 metre long dinosaur weighing in at 80 tonnes.
Around 65 million BC, dinosaurs died out and man not knows why, suggestions put forward, suggesting earth might have collided with a meteor, sending earth off its axis. For reptiles would depend on the sun and if the temperature dropped, these cold-blooded creatures would be vulnerable as their energy faded away.
Mouse sized creatures evolved into larger mammals, like tree-dwelling animals with paws and eyes. These would be the primates which evolved into apes.
The transition from boney fish to apes spanned three evolutional periods:
Better known as old, middle and new life. As our evolution changed these animals underwent physical changes.
During the Palaeozoic era, one continent which comprised of modern day; South-America, Africa, India, Australia and the Antartic was located in the southern hemisphere whilst in the north lay North America, Europe and Asia. Around 400 million BC, changes took place with the creation of mountains. Lakes and habitats attracted plants, insects and fish onto dry land. By the end of the Palaeozoic era, amphibians had evolved and were now land-based reptiles.
Come 170 million BC southern landmasses had joined with northern landmasses. The result being the creation of a vast continent. Tropical forests thrived with dinosaurs dominating the land. Smaller reptiles took to the air and sea.
By 50 million BC, earth changed once again; India was mid-ocean, America had separated itself from Africa and Europe. The Cenozoic era, saw the creation of the Alps, Himalayas, Rockies and Andes. A warm climate stimulated growth of forests as mammals multiplied, The dinosaur threat had disappeared.
Some 3.5 million years ago, what happened that day, would not be witnessed by human beings, for their day had not come, they did not exist.
A dark brown head with small eyes looked from side to side in a cautionary movement, not wanting to be prey for some hunter animal. This new animal to the food chain, with its flat-topped head, low forehead with a pronounced ridge running above its eyes, with a flattish styled nose, appeared different, no dangling arms existed.
As it slowly advanced through the long grass, satisfied no danger was obvious, it rose up, walking on two legs, not the customary four. The creature, the animal was the next step in the evolution of mankind was female and belonged to the Australopithecus Afarensis group of mammals, the first known creature to be bipedal (walk on two legs).
These Australopithecines shared many physical characteristics with gorillas and chimpanzees; they had taken the first steps on the evolutionary path to the modern day man and woman.
If we go back 15,000 million years ago, it is believed that a cosmic fireball exploded in space, creating many galaxies. Approximately 4,600 million years ago Earth was formed, and men of science have deduced that the creation of humanity started on the 23rd October 4004 BC.
It is highly unlikely, that at the point of Earth’s creation, the atmosphere would have been a safe place for human, plant and animal life. Planet Earth would have been waiting for the process of Photosynthesis to commence, leading to the release of oxygen into the atmosphere.
Photosynthesis: (Life on Earth relies on Oxygen to survive, and marine plants are known to produce seventy to eighty per cent of the oxygen in the atmosphere. Most marine plants, found in our water’s are single celled photosynthetic algae, of which there are some five thousand species.
Earth’s oceans are known to cover, some seventy percent of this planet, and land the remaining thirty per cent.
Think of the plants, which live below the waterline of our oceans, rivers and lakes, for they are providing oxygen, for our atmosphere.
An interesting thought, if man continues to pollute our oceans, he is killing of marine plants, which reduces oxygen in our atmosphere, which could destroy mankind in the future.
Single-celled organisms would be the first phase in the process, followed up by multi-celled organisms, which evolved into fish. As our evolution of Planet Earth evolved, many changes took place, before our very eyes. Large expanses of green fields would spring up, mountains were formed, rivers, lakes and seas filled with fish. As we move forward Amphibeans evolved from fish, and into reptiles able to sustain life on dry land. Birds and mammals evolved from reptiles, and human beings would be the final step in the evolution of mankind, evolving from mammals.