This chapter discusses the evolving understanding of the universe's age and the origins of life on Earth. It highlights how scientific advancements have repeatedly challenged our preconceptions about cosmic and biological history.

 

2: The Universe
How Did We Get Here?

Science can tell us a lot about history.  Often, our prejudices get in the way, however, and science just tells us, over and over, that our prejudices are wrong.  While we have a pretty good idea of the age of the solar system and the Earth, and about the evolution of life starting about 3.44 billion years ago, we can’t go all the way back to the beginning with any certainty.  We only know that the universe is every old.  I like to use Darwin’s term for this:  it is ‘of great antiquity.’  

For centuries, religious texts and philosophical traditions held that the universe was relatively young, often estimated to be around 6,000 years old. This view was rooted in interpretations of religious texts and a limited understanding of the cosmos.

The 19th century saw a significant shift in thinking about the age of the Earth and the universe. Geological evidence, such as the slow erosion of mountains and the accumulation of sediments, suggested a much older Earth. Scientists like Charles Lyell proposed that geological processes were gradual and had been operating for millions of years.

In the 20th century, astronomical observations began to provide more concrete evidence for an ancient universe. Edwin Hubble's discovery of the expanding universe in the 1920s led to the development of the Big Bang theory, which posits that the universe began as a singularity and has been expanding ever since. By measuring the rate of expansion, scientists could estimate the age of the universe. Early estimates placed the age around 10 billion years.  This figure was later extended to 13.2 billion years.

In recent decades technological advancements such as the James Webb Space Telescope have allowed astronomers to observe galaxies at incredibly distant distances. These observations have revealed that even the estimates built on the Big Bang Theory are probably far too short.  The James Webb Space Telescope has observed galaxies that appear to be fully formed and mature—billions of years old—just a few hundred million years after the Big Bang.

 

 

New theories are emerging.  A few of the more promising candidates are in the text box below. 

 

 

We have prejudices that distort the way we look at certain historical events.  We, the members of the human race, want to believe we are extremely important.  We want to think that our time of existence is all that is important and anything outside of this period of time is unimportant.  We want to make the ‘unimportant’ period as small as possible, so we look at history through a lens that makes it small and irrelevant. 

We will examine many illustrations of this prejudice later in the book.   It distorts the way we look at all aspects of reality.  We need to look at reality objectively and without bias if we are to understand how to move forward in ways that get us out of the mess we are now in.  The universe is fantastically old, compared to the time humans have existed.  Even if we accept the 13.2 billion year figure (in spite of the evidence it is far too low), and compressed it into a year (Starting on January 1) for comparison, the human experience would not begin until December 31st at 11:48, meaning a mere 12 minutes before midnight, and recorded history didn’t begin December 31st at 11:59:46 PM, a mere 14 seconds before midnight. 

 

Solar System Comes into Existence

We have considerably more certainty about the age of the solar system. 

In December of 1998, the National Aeronautics and Space Administration (NASA) hosted a seminar.  They brought together scientists to establish an evidence-based figure for the age of the solar system and of the Earth.  Here is the summary of findings from this seminar:

 

 

 

Earth Comes Into Existence

The Earth, as a member of the solar system, formed at roughly the same time as the Sun and other planets. The Earth started as a contracting ball of gas and began to form a hard surface crust about 4.4 billion years ago.

 

 

We can see many solar systems being formed from the James Webb Space Telescope.  Scientists can follow the evolution of these systems by looking a different systems in different states.  The Webb Telescope website provides many detailed images that show how planets are formed. 

QQQ earth

First Rocks

When the Earth first formed, it was not solid.  It was a gaseous mass coming together under the effect of gravity.  In 2008, researchers at McGill University discovered rocks that were the oldest rocks yet recorded, dating to being 4.28 billion years old.

 

 

3.  Life

We don’t know exactly when the first life forms came to exist on Earth.

We can only trace back to the point where we have evidence of life and assert that life originated sometime before that time.  The earliest direct evidence of life on Earth (so far) are microfossils of microorganisms mineralized in 3.465-billion-year-old Australian Apex rocks.  The illustration below shows the photographs of these life forms, along with drawings to help visualize their shapes.

 

 

 

Universal Common Ancestry

What happened to cause more complex animals to exist?  What happened to cause humans to exist?

In 1859, Charles Darwin published the book on The Origin of Species. This book proposed that it is possible (Darwin uses the term ‘not incredible’) that all life on earth started with a common primordial form, and evolved from there due to the process of natural selection.  He writes:

 

 

Recently, scientists given a formal name to the theory Darwin described.  They call it the ‘Universal Common Ancestry’ theory, or “UCA.” Understanding the UCA theory is important because it provides a foundational understanding of the realities of the world before evolution began, which can then be used to test this theory of evolution itself.

Before we look at evolution, let’s first explore how scientists have confirmed the UCA theory and the evidence supporting its validity.  This evidence comes from an the analysis of DNA.

DNA, or ‘deoxyribonucleic acid,’ is a molecule in the nucleus of the cells of all living things that have cells.  In 1954, Francis Crick, Maurice Wilkins, Rosalind Franklin, and Charles Watson built models of DNA that revealed it contained coded messages within its structure.

 

 

DNA is made up of sequences of amino acids that code for proteins and other complex molecules that are needed for life.  The coding molecules are incredibly tiny, and it took roughly a half century for scientists to build machines that could read these codes.  These machines are called ‘gene sequencers.’

In the early 2000s, Douglas Theobald and a team of researchers at the University of Colorado obtained funding to use gene-sequencing techniques and statistical analysis to evaluate the UCA theory.  If different organisms had different origins — in other words, if they were not all ‘descended from a single primordial form’ — we would expect different coding methods to be used to code for complex molecules in different life forms.

Scientists can investigate the Universal Common Ancestor (UCA) by analyzing DNA sequences for various proteins across different organisms.  For instance, they might sequence the genes of Treponema pallidum, the bacteria responsible for syphilis, and then sequence human DNA, often using their own DNA as samples.  By comparing these genetic codes, they can draw conclusions about the origins of these species.  If the species had entirely separate origins, we would expect them to use different genetic coding mechanisms.  If their origins were similar but not identical, some parts of the coding mechanisms would match while others would differ.  However, if the coding mechanisms are found to be identical, it would strongly suggest that both the syphilis bacteria and humans share a common ancestor.

Scientists can investigate the Universal Common Ancestor (UCA) by analyzing DNA sequences for various proteins across different organisms.  For instance, they might sequence the genes of Treponema pallidum, the bacteria responsible for syphilis, and then sequence human DNA, often using their own DNA as samples.  By comparing these genetic codes, they can draw conclusions about the origins of these species.  If the species had entirely separate origins, we would expect them to use different genetic coding mechanisms.  If their origins were similar but not identical, some parts of the coding mechanisms would match while others would differ.  However, if the coding mechanisms are found to be identical, it would strongly suggest that both the syphilis bacteria and humans share a common ancestor.

If scientists sequenced a wide range of life forms and found similarities in some of them, but not all of them, it would suggest evidence for common ancestry among those with all these similarities.  The more similarities they found, the higher their confidence would be in a shared ancestry.  If they discovered that every single code was identical, they would be virtually certain that all these life forms share common ancestry.

Scientists can investigate the Universal Common Ancestor (UCA) by analyzing DNA sequences for various proteins across different organisms. For instance, they might sequence the genes of Treponema pallidum, the bacteria responsible for syphilis, and then sequence human DNA, often using their own DNA as samples. By comparing these genetic codes, they can draw conclusions about the origins of these species. If the species had entirely separate origins, we would expect them to use different genetic coding mechanisms. If their origins were similar but not identical, some parts of the coding mechanisms would match while others would differ. However, if the coding mechanisms are found to be identical, it would strongly suggest that both the syphilis bacteria and humans share a common ancestor.

The team published their findings in 2010.  They found that the gene sequences for various proteins were not just similar but identical in all living things.  They used statistical tests to determine how likely this is to be a coincidence.  Here are the findings from their paper:

 

 

If scientists sequenced a wide range of life forms and found similarities in some of them, but not all of them, it would suggest evidence for common ancestry among those with all these similarities. The more similarities they found, the higher their confidence would be in a shared ancestry. If they discovered that every single code was identical, they would be virtually certain that all these life forms share common ancestry.

This means that the probability of observing such genetic similarities by chance is approximately 1 in 10^2,860 —a number so large defies human comprehension.   To put this in perspective, let's consider some astronomical numbers:

There are estimated to be about 10⁸² atoms in the observable Universe, and, if the universe did in fact have a ‘big bang’ origin, about 10¹⁷ seconds have passed since the Universe's estimated beginning. If you had all of the necessary materials and could create DNA-based life in as many different places as there are atoms in the Universe, and you repeated this process once each second for all the time since the Big Bang, you would have created life 10⁹⁹ times. Even with this astronomical number of attempts, the chances of producing the observed genetic similarities by coincidence are vanishingly small.

In fact, you would need to repeat this entire experiment—creating life 10⁹⁹ times—approximately 102,860 times before you would have a 50/50 chance of producing one world with these similarities purely by coincidence. This number, 10^2,860, represents a 1 followed by 2,860 zeros—a number so large it defies human comprehension.

In other words, it is not a coincidence that all life forms on Earth use the same genetic coding sequence in our DNA. We can conclude that we have a common ancestry with a greater degree of certainty than we know just about anything else in science. This puts the theory of Universal Common Ancestry among the most well-supported ideas in all of science, comparable to fundamental theories in physics or chemistry.

Dating Artifacts

When Darwin was alive, scientists didn’t have any scientific tools that would give accurate dates on artifacts.

People had to rely on inference from the things they accepted and believed.  Western scientists, trained as many of us, were taught that nothing in the Universe is older than 4,004 BC.  For most of the last several thousand years, people in the Western world were required to accept this belief; those who did not, were guilty of heresy and could be put to death.  While the rigidity of this requirement eased during Darwin’s time, it was still uncommon for people to openly claim that anything was older.  Naturally, if nothing is older than 4,004 BC, then all artifacts were assumed to have come to existence sometime between that date and today.

In 1949, while working at the Lawrence Livermore National Laboratory at the University of California in Berkeley, William Libby discovered the first truly scientific dating method.  This process uses the radioactive decay cycle of carbon and is called ‘radiocarbon dating.’ (See textbox below for more information.)

 

 

Scientists began using this method in 1950 and found it to be extremely reliable.  To determine just how reliable it was, they needed to find other events that occurred at a known time in the past and test artifacts from those events to see if they obtained the expected results.

We know from many sources that Mount Vesuvius in Italy erupted on August 24, 79 AD.  This eruption buried many towns before the people could escape, encasing them in lava with the exact date of their death recorded on their date books and calendars.  We can test the radiocarbon dating method by dating artifacts left by Mount Vesuvius.  Other known eruption dates allow us to verify dates going back a very long way.  This process has been tested many times and is virtually 100% accurate giving us great confidence that this method determines accurate dates.

Over the 65 years since radiocarbon dating was perfected, scientists have developed many other scientific dating methods.  Radiocarbon dating is most effective for items of recent origins (less than 50,000 years).  Older artifacts can be tested with a similar method that measures the breakdown of potassium into argon.  By cross-referencing the results of many different tests, we can determine and have determined that these tests are extremely accurate.

As of 2024, scientists have come up with  many reliable and useful dating techniques based on other elements with extremely long decay cycles.  Most of these techniques only work for organic artifacts—those that were once alive—by determining when they stopped taking in air, water, and food, meaning when they died.  New methods such as optically stimulated luminescence (OSL), are being developed to measure the amount of exposure that rocks, and anything has had to light.  By cross-referencing results from various tests using different technologies, scientists can get increasingly accurate scientific dates for artifacts of all kinds.

Evolution

The chart below lists the ages of the oldest samples of various living things dated so far.  We don’t know exactly when these organisms first appeared on Earth; they may have been here significantly longer than shown.  However, the figures below represent the minimum time we know for certain that these life forms have been on Earth:

 

 

How did one life form change into another?

Darwin’s theory, which is more than 150 years old, has held up and remains consistent with the discoveries made since.  Darwin describes the process of “natural selection,” the most important underlying process of evolution, in this way:

 

 

Over time, beings with advantageous traits replaced those without them.  The basic capabilities of the most capable beings on earth increased steadily, over billions of years.  By 60 million years ago, primates existed—Primates being the ‘family’ that includes humans.  Our ancient ancestors were present in this world 60 million years ago.

Paleogenomics

The field of Paleogenomics is the study of the evolution of DNA.  It is a brand-new field.  This is an excerpt from a 2019 article about the field:

 

 

Paleogenomics is a new field and so far, it hasn’t produced any results that conflict with the evolutionary analysis of other sciences.  The lack of conflict, however, is an important finding.  If the previous work on evolution had been incorrect, the DNA results would have shown discrepancies.  The fact that there are “no conflicts” gives us great confidence that the researchers who have studied evolutionary processes were on the right track and that all the basic processes that Darwin proposed are indeed operating.

Primates

Mammals had already existed for 140 million years before the first primates emerged.  Over this immense period, nature selected mammals with higher intelligence for survival.  The gradual increase in intelligence eventually led to animals that were so different from than their predecessors that they were an entirely new classification of beings.  Sometime between 65 million and 60 million years ago, the highly intelligent mammals that are classified as “Primates” came to exist.

Primates are mammals with these specialized features:

 

 

Incomplete remains of primates have been found and dated to 60 million years while the oldest complete skeletons go back 55 million years.  These skeletons were discovered by scientists at Beijing’s Institute of Vertebrate Paleontology and Paleoanthropology in 2013.

Evolution did not stop when the first primates emerged.  All primates reproduce sexually, and sexual reproduction creates new combinations of genes—and entirely new animals—with each birth.  Once these new generations existed, they had to compete with their peers for resources.  Those with lesser intellectual skills and abilities were less likely to perish before they could mate, while those with greater skills were more likely to carry on the species.

Every 1,000 years about 500 generations had the opportunity to surpass their peers.  Over the span of a million years, some 500,000 generations had this same opportunity.

The individual changes didn’t need to be large.  Over this immense period, tiny incremental changes accumulated to bring about enormous differences.