Earth Time
(4.5 Billion Years Ago to Now)

From Solar System Star Stuff to Planet EarthEarthApollo17

The Universe Story is undoubtedly the most important story ever told.

The Story is continuous and extends backward in time some 13.7 billion years. However, for Story telling purposes, we divided it into three parts: Deep Time, Earth Time, and Human Time.

We continue here with Earth Time that starts 4.5 billion years ago and continues to 10,000 years ago.

There are multiple ways of telling the Universe Story - Everybody's Story. At this site, we use three "languages" - so you will find examples of the spiritual/religious story; the poetic story; and the science story. You can choose the language most suited to you, because it's the same Story.

Spiritual Story

Judeo-Christmas Story (Origin: Several thousand years ago)

9 And God said, "Let the waters under the heavens be gathered together into one place, and let the dry land appear." And it was so.
10 God called the dry land Earth, and the waters that were gathered together he called Seas. And God saw that it was good.
11 And God said, "Let the earth put forth vegetation, plants yielding seed, and fruit trees bearing fruit in which is their seed, each according to its kind, upon the earth." And it was so.
12 The earth brought forth vegetation, plants yielding seed according to their own kinds, and trees bearing fruit in which is their seed, each according to its kind. And God saw that it was good.

20 And God said, "Let the waters bring forth swarms of living creatures, and let birds fly above the earth across the firmament of the heavens."
21 So God created the great sea monsters and every living creature that moves, with which the waters swarm, according to their kinds, and every winged bird according to its kind. And God saw that it was good.
22 And God blessed them, saying, "Be fruitful and multiply and fill the waters in the seas, and let birds multiply on the earth."

24 And God said, "Let the earth bring forth living creatures according to their kinds: cattle and creeping things and beasts of the earth according to their kinds." And it was so.
25 And God made the beasts ofthe earth according to their kinds and the cattle according to their kinds, and every¬thing that creeps upon the ground according to its kind. And God saw that it was good;

26 Then God said, "Let us make man in our image, after our likeness; and let them have dominion over the fish of the sea, and over the birds of the air, and over the cattle, and over all the earth, and over every creeping thing that creeps upon the earth."
27 So God created man in his own image, in the image of God he created him; male and female he created them...

 Genesis 2: 9-27

Poetic Story

Out of the Stars by Robert Weston (Modern)

...Out of the stars have we come,
up from time.
Out of the stars have we come.

Time out of time before time
in the vastness of space,
earth spun to orbit the sun,
Earth with the thunder of mountains newborn,
the boiling of seas.

Earth warmed by sun, lit by sunlight;
This is our home;
Out of the stars have we come...

Science Story (emerging )

The Earth Time Story of History of the Earth can be told in the language of science using visual images or text. We will begin with a graphical overview of the evolution of Life (and Consciousness) on Earth followed by a more detailed texual description.



UC Berkley Museum of Paleontology web site

The University of California Berkley Museum of Paleontology web site provides an overview of "Earth Time" that begins 4.5 billion years ago and continues to the present.



The Story


Precambrian Time
(4,500 to 543 mya)
(4500 to 3800 mya)
During Hadean time, the Earth and other planets in the Solar System were forming, within a large swirling cloud of gas and dust captured by the gravitational force of the sun. The oldest meteorites and lunar rocks are about 4.5 billion years old.  
(3800 to 2500 mya)
The oldest Earth rocks currently known are 3.8 billion years old. Our oldest fossils date to roughly 3.5 billion years ago, and consist of bacteria microfossils. In fact, all life during the more than one billion years of the Archaean was bacterial.  
Proterozoic Era
(2500 to 543 mya)
Stable continents first appeared and began to accrete, a long process taking about a billion years. Abundant fossils of living organisms, mostly bacteria and archaeans appeared during this period. About 1.8 billion years ago, eukaryotic cells appear as fossils too. With the beginning of the Middle Proterozoic comes the first evidence of oxygen build-up in the atmosphere. This global catastrophe spelled doom for many bacterial groups, but made possible the explosion of eukaryotic forms. These include multicellular algae, and toward the end of the Proterozoic, the first animals.

Phanerozoic Eon
(543 mya to present)
Paleozoic Era
(543 to 248 mya)
At its beginning, multicelled animals underwent a dramatic "Cambrian explosion" in diversity, and almost all living animal phyla appeared within a few millions of years.

Roughly halfway in between, animals, fungi, and plants alike colonized the land, the insects took to the air.

Much of the limestone quarried for building and industrial purposes, as well as the coal deposits of western Europe and the eastern United States, were formed during the Paleozoic.

By the end of this era, life was no longer confined to the seas. Plants had begun to colonize the land, closely followed in the Silurian by invertebrates, and in the Late Devonian by vertebrates.

At its end, the Permian extinction, 244 million years ago, the largest mass extinction in history wiped out approximately 90% of all marine animal species. Causes of these events are still not understood.


(543 to 490 mya)

(490 to 443 mya)
(443 to 417 mya)
(417 to 354 mya)
(354 to 290 mya)
(290 to 248 mya)
Mesozoic Era
(248 to 65 mya)
Mesozoic means "middle animals", and is the time during which the world fauna changed drastically from that which had been seen in the Paleozoic. Dinosaurs, which are perhaps the most popular organisms of the Mesozoic, evolved in the Triassic, but were not very diverse until the Jurassic. Except for birds, dinosaurs became extinct at the end of the Cretaceous. Some of the last dinosaurs to have lived are found in the late Cretaceous deposits of Montana in the United States.

The Mesozoic was also a time of great change in the terrestrial vegetation. The early Mesozoic was dominated by ferns, cycads, ginkgophytes, bennettitaleans, and other unusual plants. Modern gymnosperms, such as conifers, first appeared in their current recognizable forms in the early Triassic.

By the middle of the Cretaceous, the earliest angiosperms (flowering plants) had appeared and began to diversify, largely taking over from the other plant groups. Nearly all of our food comes from flowering plants; grains, beans, nuts, fruits, vegetables, herbs and spices almost all come from plants with flowers, as do tea, coffee, chocolate, wine, beer, tequila, and cola. Much of our clothing comes from them as well -- cotton and linen are made from "fibers" of flowering plants, as are rope and burlap, and many commercial dyes are extracted from other flowering plants. We also owe them credit for a large number of our drugs, including over-the-counter medicines such as aspirin, prescribed drugs such as digitalis and atropine, and controlled drugs such as opium, cocaine, marijuana, and tobacco.
Triassic (245-208 Million Years Ago),

Jurassic (208-146 Million Years Ago)
Cretaceous (146-65 Million Years Ago).
Cenozoic Era
(65 mya to today)

The Cenozoic is the most recent of the three major subdivisions of animal history. The Cenozoic is divided into two main sub-divisions: the Tertiary and the Quaternary.

Paleocene: Prior to the Paleocene, mammals appear first in the late Triassic (about 210 mya), at about the same time as dinosaurs. Throughout the prior Mesozoic era, most mammals were small, fed on insects and lead a nocturnal life, whereas dinosaurs were the dominant forms of life on land. This situation changed abruptly about 65 million years ago, when dinosaurs disappeared with the exception of their descendants, the birds, probably as the result of a meteorite impact. At the beginning of the Paleocene epoch, the world was practically without larger sized terrestrial animals. This unique situation was the starting point for the great evolutionary success of the mammals. Only ten million years later, at the end of the Paleocene, they had occupied a large part of the vacant ecological niches. By this time, the landscape was teeming with small insectivorous and rodent-like mammals, medium sized mammals were searching the forests for any kind of food they could cope with, the first large (but not yet gigantic) mammals were browsing on the abundant vegetation, and carnivorous mammals were stalking their prey.

Despite this impressive diversification, most Paleocene mammals are still on a primitive level of anatomy in comparison to mammals of today. Often they show only the first beginning of specializations that characterize their descendants from later epochs, such as optimization of the teeth for a special kind of food or adaptations of the limbs to fast running. The Paleocene mammalian fauna is therefore often called archaic.

The beginning of the following epoch, the Eocene, brought about an important modernization of this fauna. Several groups of mammals with more modern appearance spread over the northern hemisphere at this time, whereas the decline of the archaic forms started. The oldest known fossils of most of the modern orders of mammals appear in a brief period during the Early Eocene and all were small, under 10 kg.

The Oligocene is thus a relatively short span of time, though a number of major changes occurred during this time. These include the appearance of the first elephants with trunks, early horses, and the appearance of many grasses -- plants that would produce vast tracts of grasslands in the following epoch, the Miocene.

The Miocene was a time of warmer global climates than those in the preceeding Oligocene, or the following Pliocene. It is particularly notable in that two major ecosystems first appeared at this time: kelp forests and grasslands. The expansion of grasslands is correlated to a drying of continental interiors as the global climate first warmed and then cooled.

Global circulation patterns changed as Antarctica became isolated and the circum-polar ocean circulation became established. This reduced significantly the mixing or warmer tropical water and cold polar water, and permitted the buildup of the Antarctic polar cap. Likewise, the African-Arabian plate joined to Asia, closing the seaway which had previously separated Africa from Asia, and a number of migrations of animals brought these two faunas into contact.

Tertiary (65 to 2.6 mya)
Paleocene (65 to 54.8 mya)

(54.8 to 33.7 mya)

(33.7 to 23.8 mya)

(23.8 to 5.3 mya)

(5.3 to 2.6 mya)

Quaternary (2.6 mya to today)
Pleistocene (2.6 mya to 10,000 yrs)
Holocene (10,000 years to today)




As we reflect on the past 4.5 billion years illustrated in the graphic above, we are in awe of the ever increasing complexity that has emerged. The evolving complexity of our Ecosystem is only possible by the persistent addition of energy (from the Sun) that becomes embedded in new chemical bonds (new relationships between the Earth's basic elements) that comprise all forms of Life.

Chemistry + Light(energy) = Life + Consciousness

At this point, we humans appear to be at the end of one of the branches of the tree of Life; we appear to be one of if not the most complex forms of Life. We have enough complexity to record/store & recall (remember/replay) intricate sequences of stimuli abstractly - after the fact - before the fact. As a result, we developed an ability to communicate these rememberences / imaginations to our fellow humans via pictographs, symbols, sounds, language, ... all the tools of collective learning. To our knowledge, no other living species has developed this unique capability - to transcend the memory of the DNA and convey life experiences to the next generation in an abstract way. We call it education (and it is so common some have recently begun to take it for granted and to devalue it.)

Consciousness has continued to increase in complexity with the emerging awareness that indeed our planet and all of us inhabitants, human and non-human, make up a cohabitating system often referred to as Gaia. At the moment we (life on Earth) appear to be a rather unique in the mass of star stuff known as our solar system.

The visual images of earth taken from a perspective beyond earth also convey the fact that during the natural evolution of the planet, nature did not construct political boundaries, or barbed wire fences to prevent /restrict movement of its human and non-human population.

Although we appear alone, we are also connected to our star, the Sun, by the invisible force of gravity, and to a lesser degree to each of the hundreds of billions of bodies that make up our Milky Way galaxy, and to an even lesser degree to the hundreds of billions of galaxies that make up our universe.

Likewise we commune with and are connected to our Sun and all the other heavenly bodies via electromagnetic energy (e.g. light, radio waves, x-rays,…).


Summary / Conclusions
Like a classical symphony comprised of three movements, we will not applaud at the end of Part II and break the continuity of the Story. This is a Story of a sacred work - a work that will be played only once.  

Let's simply pause, reflect for a moment on this last movement, how ....


The story written in the fossil record can now be read in the new records - of artwork on the walls of caves - carved into stone, writtten on parchment, and modern paper, and now stories that come to us on invisible messengers we call waves that emerge from radios and televisions and monitors and tablets and phones.

The stage is now prepared for Part II, we call Human Time.   

For Further Reflection

  • What does this part of the Universe Story tell us?
  • How do you personally connect to this part of the Universe Story?
  • What are we able to take away from these observations?
  • By observing the past (history) we call Deep Time, what might we learn about the future? 
  • What are we now aware of today that we were not aware of 100, 1000, 10,000 years ago?
    (e.g. That all Life on Earth is related - has common ancestry.)