CREATION OF LIFE
AND BIOLOGICAL EVOLUTION ( Page 6) |
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| The descendants of this reptile and probably some forms
of amphibians were populating the dry land and multiplying fast when
catastrophe struck about 250 million years ago. This caused the extinction
of 90% of the life on earth, forests, animals, as well as aquatic
life. The decaying forests caused an abnormal increase in the propagation
of fungi. The presence of excessive quantities of the remnants of
fungi in the rock layers of this period is what gave away the clue
to this catastrophe. What did cause this super-massive natural disaster?
Was it meteorites or abnormally high volcanic action or a deluge?
Or was it a combination of all these? Probably a combined attack.
The impact, at close intervals of two or more large meteors could
have melted the crust of the earth and unleashed volcanic activity
of extremely high magnitude. The temperature rose too high and the
dust and fumes that filled the skies blocked out the sun for a very
long period of time. It was just providence that this catastrophe
did not wipe out life entirely from the face of the earth. |
| This event could have also kick-started the process
that led to the break up of the single landmass into continents, the
process of plate tectonics. Nor was this the first catastrophe of
its kind. It was rather a common occurrence. Though very destructive
in nature these so-called catastrophes had helped in shaping the earth
and life on it into what it is today. The disaster that destroyed
90% of life seems to have at the same time made the earth more fertile
and habitable. In a couple of million years time, when the dust and
cloud had settled after the devastation, there was an unprecedented
and accelerated growth of life forms on land. From this debris grew
immense forests of conifers, cacti and giant ferns. The reptilian
population that survived this disaster began to grow like nobody’s
business. This was the Jurassic age of dinosaurs. Animals of that
size and mass had not been found on earth before or after this period. |
| Mammals |
| The age of the dinosaurs lasted roughly 150 million
years. This was the period when the first birds evolved from the reptiles
and invented the new and fast mode of transport - flight. This period
also saw the appearance of the first mammals, probably tiny rodents.
In the plant kingdom also there were new developments, such as the
appearance of flowering plants like grass followed by trees. The reign
of the reptilian giants on land ended some 65 million years ago as
a result of another catastrophe, though not as devastating as the
one before that. The most probable cause in this case also is impact
of meteors. Whatever the physical cause of the extinction of the dinosaurs,
the real cause in my opinion is that the earth could not bear them
any more. They had grown too big and too destructive and the One “up
there” decided it is time to put an end to their tyranny. Another
way of putting it is that nature has its own ways of safeguarding
the overall interest of life on earth and will not allow any one species
to have its own way at the expense of others. Humans have destroyed
more forests than the dinosaurs but man has replaced most of them
with some other form of vegetation, crops, farms or plantations. Yet
today scientists are concerned about the damage to ecology that we
are doing and are planning measures to counteract them. Hence all
the frenzy of conservation. |
| Though all the huge forms of reptiles became extinct
in this process, the lesser reptiles did survive. The crocodile, Komodo
dragon and monitor lizard can be considered the living fossils of
the Jurassic age. The mammals that survived began to evolve fast to
take over the leading role left by the dinosaurs. We see an explosive
increase in the families and species of mammals during the last 90
million years. The ancestor of primates - of monkeys, apes and humans
- came on the scene about 70 million years ago. These were lower primates,
like lemurs or bush babies. Scientists call them Prosimiens, meaning
‘before the apes’. Higher primates or anthropoids branched
off from this line around 45 million years ago. This is the group
that gave rise to monkeys, apes and humans. During the last 7 million
years the chimpanzees and guerrillas have not evolved much but the
other branch that led to us underwent unbelievable changes in that
relatively short span of time. But then that is another story. |
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