1: The Universe
How did the world around us get here?
Many creation theories—theories about how the world came to exist—seem designed to manipulate people, not inform and enlighten. For example, I was taught that a superbeing in the sky made everything in a magical process, a process that violated all of the known laws of physics. This being was a god whose name, I was told, was ‘Jehovah.’
Jehovah said a few words and the heavens and the earth appeared. Then a few more words and light appeared. Jehovah used this method (incantations) to divide the waters from the waters to create land, then create plants and animals, then man, and then, out of man, woman. At a certain point, Jehovah created the societies that are now in place: He divided the land into nations and gave the pieces away to different people. Jehovah then set these countries against each other in battle, by creating war. He then accepted that the winners of wars had gained rights, and the losers lost rights to the land.
Why did Jehovah do these things?
My teachers didn’t seem to have an answer for this question.
In fact, they couldn’t explain much of anything about the reasons anything in history happened. They only said that Jehovah is very wise and loves us all with all his heart. We don’t know Jehovah’s reasons and can’t know them—Jehovah is so high above us that mere humans can never really understand him. But we know that, whatever the reasons, they are based on love, compassion, benevolence, and concern for our souls. Whatever the reason for Jehovah’s actions, it is a good one, one we must not question
If we accept this version of ‘how the world got here,’ we are led to believe that we are supposed to be acting a certain very specific way: The world is divided into countries because it is supposed to be divided this way. Jehovah gave certain groups of people and their descendents these ‘countries’ and granted these countries their rights and we, the people of the world, are supposed to respect this.
If this is the way the world came to exist, there is no question about how we are supposed to be acting: We are supposed to be playing our part to make sure the countries that Jehovah gave us succeed in war. We are supposed to be working hard, paying taxes, and fighting, killing, and even giving our own lives, if we think this can provide military advantages to the countries that have gained rights—through divine will—through the wars and other events that the creator has orchestrated.
We are supposed to do as we are told.
We have great intellects. These are gifts that Jehovah gave us to help us figure out the best way to accomplish the goals of our countries and the best way to defeat our enemies. We are not supposed to be using these intellects to try to discover things that the creator does not want us to know (or He would have told us these things).
If the above version of creation is correct, we are clearly supposed to act a certain way.
But what if this version of the events that led to the existence of everything in the world around us is wrong?
What if there is another possible way that the world around us could have come to exist, one that is logical, reasonable, and conforms totally to all known laws of physics?
If we accept this other version, we don’t really have any reference that can tell us how we are supposed to be acting. It isn’t logical or reasonable to act as described above. It doesn’t bring benefits to our race or move us toward any realistic goal we may have for life itself. In other words, logic tells use that we aren’t really supposed to be doing the things that we are told we are supposed to be doing at all. If we use logic, we would be led to believe that there are people who benefit from this way of life and they have manipulated us to try to get more benefits. We are led to believe that the people who benefit might be using the above creation story to manipulate us and turn us into their tools.
Very recently, people have found scientific techniques that can help us see that it isn’t necessary to evoke stories of magic or invisible beings that have the ability to create entire universes out of thin air to explain the existence of the world. Science, they tell us, can help us understand everything.
The Early Years
In December of 1998, the National Aeronautics and Space Administration (NASA) hosted a seminar. They brought together scientists to come up with an evidence-based figure for the age of the solar system and of the earth. Here is the summary of findings from this seminar:
The oldest materials that formed in the Solar System are inclusions rich in calcium and aluminum found within carbonaceous chondrite meteorites. Nicknamed CAIs (for Calcium-Aluminum-rich Inclusions), these objects are thought to have been some of the first solids to form after the cloud of gas and dust began to heat up. CAIs have ages of 4.566 billion years. On the basis of measurements of several isotopes, the earth and Moon formed about 50 to 100 million years later. [Origin of the earth and Moon, 1998, LPI Contribution No. 957, Lunar and Planetary Institute, Houston.]
The science is complex and involves a basic understanding of nuclear physics, but here is a quick and simplified version:
Isotopes are different varieties of the same atom; all isotopes of the same element have the same number of protons and electrons, but different numbers of neutrons. Scientists have found that atoms formed while solar systems come to exist are highly unstable; they generally have more neutrons than the quantum forces inside the nucleus can keep together. They throw off neutrons in a very predictable and understandable way over time. As this happens, the ratio of isotopes changes; scientists can determine the age of the rocks from the ratio of the isotopes.
When scientists want to understand things, they start by coming up with a theory about how things might have happened. At first, the theory is nothing but a guess. They then use experiments and observations to try to confirm or reject the theory. The more pieces of information they have that support the theory, the more confidence they have that the theory is correct. Since 1998, astrophysicists have developed a great many tools used to test the initial theory that the solar system is 4.566 billion years old and the earth came into existence 50 to 100 million years later.
More recently, scientists have put powerful telescopes into space that can see very remote objects. We can actually see the events that take place when solar systems come to exist and take photographs of the event. The picture below is a photograph taken from the Hubble telescope. It is an actual photograph of a planetary system being formed.
Some of the more recent tests have provided slightly older dates for the formation of the solar system, and the consensus as of this writing in 2020 is closer to 4.65 billion years for the formation of the solar system and 4.6 billion years for the formation of the earth. Of course, new scientific tools will be found, and it is possible that they may cause us to modify our estimates of the age in the future. But most likely, any modifications to the currently accepted figure of 4.65 billion years will be relatively small and we can say with a great deal of confidence that the solar system is about 4.65 billion years old. The basic outlines of the earth—as a gas cloud that was condensing and would eventually become solid—formed sometime around 500 million years into this process, or 4.6 billion years ago.
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, dated to 4.28 billion years old.
O’Neil and colleagues estimated the age of the rocks using isotopic dating, which analyzes the decay of the radioactive element neodymium-142 contained within them. This technique can only be used to date rocks roughly 4.1 billion years old or older; this is the first time it has ever been used to date terrestrial rocks, because nothing this old has ever been discovered before
“There have been older dates from Western Australia for isolated resistant mineral grains called zircons,” says Carlson, “but these are the oldest whole rocks found so far.” The oldest zircon dates are 4.36 billion years. Before this study, the oldest dated rocks were from a body of rock known as the Acasta Gneiss in the Northwest Territories, which are 4.03 billion years old. The earth is 4.6 billion years old, and remnants of its early crust are extremely rare—most of it has been mashed and recycled into earth’s interior several times over by plate tectonics since the earth formed. *
Before the first rocks, the earth was extremely hot, far above the temperature where liquid water could exist. No life forms on earth today can survive at the very high temperatures of molten rock so if there were living things on earth before the first rocks, they were built on an entirely different foundation than current life forms. For practical purposes and for purposes of historical analysis, we can rule out life on earth before 4.36 billion years ago.
We don’t know for sure when the first life forms came to exist on earth. We can only go back to the point where we have evidence of life and claim that we know 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 photographed life forms, together with drawings made to make it easier to see 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. (You can get a PDF version of this book from the resources tab on the PossibleSocieties.com website.) 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:
On the principle of natural selection with divergence of character, it does not seem incredible that, from some such low and intermediate form, both animals and plants may have been developed; and, if we admit this, we must likewise admit that all the organic beings that have ever lived on this earth may be descended from some one primordial form. (PDF of book available in references section of PossibleSocieties.com website.)
Recently, scientists have come up with a formal name for the theory Darwin described. They call it the ‘universal common ancestry’ theory, or ‘UCA.’ It is important to understand the UCA theory because, if we understand it, we will have a foundational understanding of the realities of the world before evolution began and can use this to test the theory of evolution itself.
Before we look at evolution, let’s look at the way scientists have confirmed the UCA theory and the evidence that it is true. This evidence comes from an 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, and Charles Watson built models of DNA that showed it had coded messages written inside it. The DNA has sequences of amino acids that code for proteins and other complex molecules 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 test the UCA theory. If different organisms had different origins—in other words, if they weren’t all ‘descended from some one primordial form’—we would expect different coding methods to be used to code for complex molecules in different life forms.
Scientists can test UCA by comparing the sequences in DNA for various proteins in different organisms. For example, they may sequence the genes of the Treponema pallidum bacteria that cause syphilis, and then sequence human DNA (many scientists use their own DNA for samples). They can then compare the codes. If these two species had different origins, we would expect them to use different coding mechanisms. If they had similar but not identical origins, we would expect parts of the coding mechanism to work the same way, with other parts working differently. If they found that the coding mechanisms were identical, they would have a high degree of confidence that the syphilis bacteria and human beings had a common ancestor.
If scientists sequenced a lot of different life forms, and found similarities in some of them, but not all of them, we would have evidence for common ancestry in all those life forms that had these similarities. If they found a very large number of similarities, they would have a high degree of confidence in common ancestry. If they found that every single one of the codes was identical, they would be virtually certain that all these life forms had common ancestry.
The team published their findings in 2010. They found that the gene sequences for various proteins were not just similar; they were identical in all living things. They used standard tests to determine how likely this is to be a coincidence. Here are their findings, from their paper:
UCA is at least 102,860 times more probable than the closest competing hypothesis. Notably, UCA is the most accurate and the most parsimonious hypothesis. Compared to the multiple-ancestry hypotheses, UCA provides a much better fit to the data (as seen from its higher likelihood), and it is also the least complex (as judged by the number of parameters). [Theobald, Douglas L. “A Formal Test of the Theory of Universal Common Ancestry,” Nature 465, 219-222 (May 2010).]
Basically, this means that if you could create DNA-based life a total of 102,860 different times leading to 102,860 worlds covered with life, you would only have one instance where the DNA of the different life forms would coincide to the same degree as we observe on earth, if random chance determined the results. The number 102,860 is a 1 with 2,860 zeros after it. This is a very large number
For reference, there are estimated to be 1082 atoms in the entire universe. [Villanueva, John Carl. “How Many Atoms Are There in the Universe?” Universe Today, July 30, 2009.] There have been about 1017 seconds since the Big Bang. If you could create DNA-based life by as many times as there are atoms in the universe, and then did this once each second for all the time that has passed since the Big Bang, you would have created life 1099 times. If you have a background in math, you will be able to see that we are still a fantastic way away from having any real chance of getting this coincidence: We would need to make these changes 102,760 (a 1 with 2,760 zeros after it) times before we got a 50/50 chance of getting one world with these similarities due only to coincidence.
In other words, it is not a coincidence that all life forms on earth use the same genetic coding sequence in our DNA. We know that we have a common ancestry with a greater degree of certainty than we know just about anything.
When Darwin was alive, scientists didn’t have any scientific tools that would give accurate dates on artifacts.
People had to use inference from the things they accepted and believed. Western scientists, trained as I was, were taught that nothing in the universe is older than 4,004 BC. (For most of the last several thousand years, people were required to accept this in the western world; those who didn’t were guilty of heresy and could be put to death. The requirements were eased somewhat during Darwin’s time, but it was still uncommon for people to openly state that anything was older.) Of course, if nothing is older than 4,004 BC, all artifacts must have come to exist sometime between this date and today.
In 1949, William Libby, while working at the Lawrence Livermore National Laboratory at the University of California in Berkeley, discovered the first truly scientific dating method. This process used the radioactive decay cycle of carbon, and is called ‘radiocarbon dating.’ (See textbox below for more information.)
Gamma radiation from the sun changes stable carbon-12 to radioactive carbon-14 at a fixed rate, and carbon-14 degrades to carbon-12 at a known rate; the relative ratios of these two kinds of carbon have reached an equilibrium billions of years ago. The new carbon-14 created exactly equals the carbon-14 that disappears, and the ratio stays the same.
All plants ‘breathe in’ carbon; they take in carbon dioxide and convert it to sugars using photosynthesis. Animals eat plants, taking the plant’s carbon into their bodies. Once the plant or animal dies, it stops taking in carbon and there is no more carbon-14 being created (it is only created in the atmosphere due to the sun’s UV rays), so the relative ratio of carbon-14 to carbon-12 falls, as the amount of carbon-14 falls. Eventually, after about 50,000 years, the carbon-14 has all disappeared and there is none left.
During the first 50,000 years after the death of a plant or animal, the ratio of these two isotopes of carbon changes from its natural ratio in the atmosphere to zero. Scientists can measure the ratios of these two isotopes in a sample and go to a chart that tells them how long that carbon has been out of the atmosphere, to within a few years. *
Scientists started to use this method in 1950 and found it to be extremely reliable. To find out just how reliable it was, they had to find other events that took place at a known time in the past and test artifacts of those events to determine if they got the expected result
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 leave; this led to many people encased in lava with the exact date of their death known (shown on their date books and calendars). We can test the radiocarbon dating method by dating artifacts left by Mount Vesuvius. Other eruption dates are known, allowing us to check dates going back a very long way. The process has been tested many times and has been found to be virtually 100% accurate. We have great confidence that this method gives accurate dates
Over the 65 years after radiocarbon dating was perfected, scientists created a great many other scientific dating methods. Radiocarbon dating is best for items of recent origins (less than 50,000 years). Older artifacts can be tested with a similar tool that measures the breakdown of potassium into argon. By cross-referencing the results of many different testing samples, we can determine and have determined that these tests are extremely accurate
As of 2023, we have a great many dating techniques based on other elements with extremely long decay cycles. We can now date artifacts that are hundreds of millions or even billions of years old.
The chart below lists the ages of the oldest sample dated so far of various living things. We don’t know exactly when these living things first appeared on earth; they may have been here significantly longer than shown, but the figures below show the time that we know for sure these things have been on earth:
For the last 3.4 billion
years, simple cells (prokaryotes) have existed;
For the last 3.4 billion years, cyanobacteria performing photosynthesis have existed;
For the last 2 billion years, complex cells (eukaryotes) have existed;
For the last 1.2 billion years, eukaryotes which sexually reproduce have existed;
For the last 1 billion years, multicellular life has existed;
For the last 600 million years, simple animals have existed;
For the last 500 million years, fish and proto–amphibians have existed;
For the last 475 million years, land plants have existed;
For the last 400 million years, insects and seeds have existed;
For the last 360 million years, amphibians have existed;
For the last 300 million years, reptiles have existed;
For the last 200 million years, mammals have existed;
For the last 150 million years, birds have existed;
For the last 130 million years, flowers have existed;
For the last 60 million years, primates have existed.*
How did one life form change into another?
Darwin’s theory about this is more than a century old. It has held up and is totally consistent with the results discovered. Darwin describes the process of ‘natural selection,’ the most important underlying process of evolution, this way:
As many more individuals of each species are born than can possibly survive; and as, consequently, there is a frequently recurrent struggle for existence, it follows that any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected. From the strong principle of inheritance, any selected variety will tend to propagate its new and modified form.
Over time, beings with advantages replaced those that didn’t have these advantages. The basic capabilities of the most capable beings on earth increased steadily, over billions of years. By 60 million years ago, primates existed. Primates are the ‘family’ that includes humans. Our ancient ancestors were on this world 60 million years ago
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:
The recent accumulation of plant genomic resources has provided an unprecedented opportunity to compare modern genomes with each other and to infer their evolutionary history from the reconstructed genomes of their most recent common ancestors (MRCA). Such ancestral genome reconstruction was initially used to investigate 105 million years of eutherian (placental) mammal evolution. Eutherian genomes have been found to be surprisingly stable, and affected by only a limited number of large-scale rearrangements during evolution. Higher rates of such chromosomal shuffling have been reported for the branch extending from the great ape ancestor to the ancestor of humans and chimpanzees, which diverged after the Cretaceous–Paleogene (K–Pg) boundary, at a time when the dinosaurs became extinct.
Computational reconstructions of mammalian ancestral genomes were instrumental in suggesting that environmental changes may have driven genome plasticity through chromosome rearrangements. These changes may also have led to new variation in gene content and gene expression that gave rise to key adaptive biological functions.
Paleogenomics is a new field and hasn’t produced any results that conflict with the findings of other sciences. No conflict, however, is an important finding. If the previous work on evolution had been wrong, the DNA results would provide findings that were unexpected. ‘No conflicts’ gives us great confidence that the people who have worked out the processes behind evolution were on the right track and that all the basic processes that Darwin claimed must be operating are, indeed, operating.
Mammals had already been around for 140 million years before the first primates came to exist. Over this immense period of time, nature selected mammals with higher intelligence for survival. The gradual increase in intelligence eventually led to animals that were so much different than their predecessors that they were an entirely different classification of beings. Sometime between 65 million and 60 million years ago, the extremely intelligent mammals that are classified as ‘primates’ came to exist.
Primates are mammals with these specialized features:
Grasping hands with fingernails (rather than claws) and fingerprints
Large brains relative to their body mass
Vision is their primary sense and they are highly visually oriented
They normally give birth to one offspring at a time
They have very long periods of growth & development
They tend to live in long-lasting social groups
Primates are the only class of animals that take natural products and use them to manufacture tools
Incomplete remains of primates have been found and dated to 60 million years. The oldest complete skeletons go back 55 million years. Scientists at Beijing’s Institute of Vertebrate Paleontology and Paleoanthropology found them in 2013.
Evolution did not stop when the first primates came to exist. All primates reproduce sexually, and sexual reproduction creates new combinations of genes—and entirely new animals—with each baby born. Once the babies came to exist, they had to compete against their peers for resources. Those with lesser intellectual skills and talents were selected to perish before they could mate; the ones with greater skills were selected to carry on the species.
Each 1,000 years, some 500 generations would have a chance to surpass their peers. Each 1,000,000 years, some 500,000 generations had this same chance.
The individual changes didn’t have to be big. Over this immense period of time, just tiny incremental changes added together to bring about enormous differences.