The answer is *probably* not.
There's no evidence to support the idea of previous ancient civilizations from prehistory. In fact, one of the reasons we consider it is because we
struggle to comprehend such a vast timescale and the evolution that led to the current inhabitants of this blue planet.
According to the best evidence the Earth was geologically hyperactive in its earliest development. Far too hostile for any life as we know it to
evolve...and right on the doorstep of abiogenesis. The evidence that Earth went through this period of molten plasticity and poisonous atmosphere is
to be found in the rock strata beneath out feet and in the tectonic plates that are pushing up mountain ranges ever since. Metamorphic and igneous
rocks underly sedimentary layers.
[atsimg]http://files.abovetopsecret.com/images/member/6ea2085b12f3.gif[/atsimg]
Life began during the
PreCambrian
This interval represents more than 80% of the geologic record and thus provides important evidence of how the continents evolved. The Precambrian
is divided into the Archean and Proterozoic eons, with the boundary between them at 2.5 billion years ago. It was originally defined as the era that
predated the emergence of life in the Cambrian Period. It is now known, however, that life on Earth had begun by the early pre Cambrian.
So for 80% of Earth's history there was little or no life. 3.5 billion years ago, the first evidence of life begins to show up in the fossil record.
Protokaryotes..single-celled critters with no cell nucleus. Eukaryotes followed up to a billion years later. All very dull and spanning a vast period
of time! The spread of life affected the atmosphere of Earth and began to create an environment and atmosphere more suited to life as we know it.
Millions of years of photosynthesis pumped oxygen into an atmosphere that previously had little or none.
The
Cambrian Explosion is when it all kicked off. This is the period when the Earth's seas
became a teeming mass of evolving life. Recognisable life forms began to appear...critters that have features we can identify today. This had a
massive effect on the environment and atmosphere. The changes are recorded in the fossil record. The atmospheric changes are recorded in ice-core
samples and geology. These can be dated and cross-referenced against other analyses to present a time line of life's evolution. It ended around
480million years ago and still the Earth was probably devoid of life.
To the best of our knowledge, it took 4 billion years to get to crustaceans. The following 500 million years has led up to us. The fossil record
leads us dimly through these vast time spans. It's a familiar story and I won't go into detail. Fish to amphibian. Natural selection, speciation and
specialization across a backdrop of ice ages, land mass migration. The rise and fall of dinosaurs and the tons of fossils that remain. The rise of
mammals, smaller reptiles, diversity of insects etc.
The common ancestor of the primates had been evolving and diversifying since the late days of the dinosaurs. Some 60 million years ago the first
recognisable primate fossils are laid down.
[atsimg]http://files.abovetopsecret.com/images/member/3fe0ab152d2d.jpg[/atsimg]
[atsimg]http://files.abovetopsecret.com/images/member/13b6cf288ea9.jpg[/atsimg]
The idea that humans have evolved and then disappeared to evolve again. That we have had cataclysms that killed us off or world floods that made us
largely extinct? There's no evidence to support it. Sure, there are gaps in our knowledge...huge voids and the fossil record isn't a finished
tapestry. What we DO know is well accounted for by evidence...