Eukaryotic cells are cells with internal organs, organelles and the DNA is in the nucleus. The predecessor prokaryote cells do not have a nucleus, but do have DNA. All cells in all animals, plants, and insects are eukaryotic, but all animals, plants, and insects host millions of critters based on both eukaryotic and prokaryote cells.

Organisms that consist of more than one cell took several billion years to evolve from unicellular organisms. All species of animals, land plants and most fungi are multicellular, as well as many algae. A few organisms are partially both such as slime molds and social amoebae.

The earliest known vertebrates originated about 525 million BCE during the Cambrian explosion. 

The millipede Pneumodesmus newmani is the oldest air-breathing animal known to date. This ancient denizen of the Scottish waters once roamed the Earth during the early Silurian era. The millipede likely supplemented its oxygen intake through air as well as using its gills while in water.
 
 

Animation of the break-up of the supercontinent Pangaea and the subsequent drift of its constituents, from the Early Triassic to recent (250 Million BCE to 1 CE). The super continent Pangaea existed from about 335 to 175 Million BCE.

The appendix is a small, finger-shaped pouch attached to the large intestine. It has long been considered a vestigial organ, meaning that it has no function in the human body. However, recent research suggests that the appendix may actually serve as a reservoir for beneficial gut bacteria.

The appendix is an example of a Phenotype Variation — a trait that varies among individuals. In fact, something like 1 in 100,000 people are born without an appendix. The presence or absence of the appendix is one example of a variation in humans. However, the presence or absence of the appendix is not a typical example of phenotype variation, as it is not a continuous range of variation within a population. Nonetheless, it is an interesting variation that our descendants over the next eons will certainly observe.

North America splits from Europe. Over millions of years, the modern-day Europe (Eurasian plate) and North America (North American Plate) separated during the final breakup of Pangaea in the early Cenozoic Era. This split is a later part of that breakup and created the North Atlantic Ocean.

Sahelanthropus tchadensis has two human anatomical traits: small canine teeth, and walking upright on two legs. We believe it walked on two legs because the large opening where the spinal cord exits out of the cranium from the brain is located further forward (on the underside of the cranium) than in apes or any other primate except humans.

Homo Habilis lived about 2.3 to 1.65 million BCE. They had larger brains than predecessors and used stone tools as well as used and controlled fire. They were likely the first hominids to explore most of the Earth. We know these hominids evolved into at least 20 known species of which only Homo Sapiens survive today.

Some of our extinct distant cousins but NOT* our ancestors:

• Homo antecessor: 1.2 million to 800,000 BCE (Spain; maybe England and France)
• Homo erectus**: 2 million to 108,000 BCE (Eurasia)
• Homo floresiensis: 60,000 to 50,000 BCE (Indonesian island of Flores)
• Homo luzonensis: 67,000 to 50,000 BCE (Philippines)
• Homo naledi: 335,000 to 236,000 BCE (Africa, along side our direct ancestors)

Our distant cousins exhibited some human traits including cave dwelling, controlled fire, team hunting, and butchering of prey with tools. The surviving tools found are made of stone and bone but it is very likely they used other less durable types of materials like wood, vines, feathers, sticks, etc. For example, the hand axe dates back to before 2 million BCE. All this evidence indicates these human traits likely evolved before 2 million BCE.

*No valid evidence, and not currently thought to be an ancestor. 
**There is a debatable hypothesis that homo erectus explored the world, returned to Africa, and those that returned evolved into homo ergaster and are our direct line ancestors.

Oldest undisputed evidence of hominins walking upright efficiently, probably Homo erectus. Our style of upright walking is energetic and efficient. We use a long stride with a spring-like mechanism in the arch of our foot. These footprints found in Kenya are dated to 1.52 million BCE. They show evidence of a well-developed arch and a long stride ending in a propulsive toe-off of modern people.

Burned flint tools dated to circa 790,000 BCE were discovered at Gesher Benot Ya’aquov, Israel.

Humans and Neanderthals had a common ancestor about 400,000 BCE (current estimates range from 320,000 to 800,000 BCE). Humans did not evolve from Neanderthals, but both are the current evolution of a common ancestor tentatively identified as Homo Heidelbergensis. After the split, Homo Sapiens and Neanderthals interbred up to and as recently as 40,000 BCE. Through DNA testing we can identify DNA that came from interbreeding with Neanderthals. Neanderthals became extinct about 40,000 BCE. They built shelters, wore clothes, used tools, and spoke. We know that about .03% to 4% of the genes in non-African modern humans is from Neanderthals. Neanderthal DNA in modern humans is the highest in East Asians, intermediate in Europeans, and lower in Southeast Asians. 

The common ancestor tentatively identified as Homo Heidelbergensis lived from about 600,000 to 200,000 BCE. The 400,000 BCE documented here is just a reasonable guess.

The first humans evolved in Africa about 315,000 BCE. These first humans had most of the traits we identify as human including looking and thinking much as we do. They used brain power, innovation, and teamwork. They spoke and controlled fire. Their lives were complex. Over the next 250,000 years they evolved into us. By about 150,000 BCE our current capabilities were mostly evolved. Today’s humans have essentially the same DNA as humans from circa 60,000 BCE.

All humans today share a single grandpa, circa 275,000 BCE. We know this because all humans alive today share our ancestor’s haplogroup A genes — from our Y chromosome. He was one of many thousands of men living in eastern Africa. Many paternal lines survived for many generations but ultimately over time all the other male lineages died out. Adam’s descendants met our Eve about 100,000 years later–about 4,000 generations later.

By circa 150,000 BCE, the size of our brain and it’s capabilities matured. Think about this. A human born today and a human born in 150,000 BCE had roughly the same mental and physical capacities. This includes all of our traits including our need for attention and power, our ingenuity, our gullibility to believe things, and our intolerance of the unknown and different. If a human from this time landed in a modern morgue, the doctor performing yet another autopsy would most likely think it was a modern human.

How many times since 150,000 BCE did humans create new religions and Gods? How many times did they discover or invent things that were then lost for thousands of years? Human knowledge builds on previous knowledge, but only if it can be passed down, and survive the test of time. It’s reasonable to believe that various forms of writing and labels were developed and lost countless times. Many interesting advances developed, and lost. No doubt, the stubborn belief in myth or dogma has led directly to the suppression of various human advances countless times. Many times through the use of war and genocide.

Let’s look at just one modern human example. We know the Greeks several thousand years ago knew the Earth was a globe. Over time, the information, the advance, was lost because of the belief in myth and a desire to control others.

Circa 76,000 BCE someone, perhaps the child’s parents, carefully prepared a human child aged about three years old for burial. They dug a circular pit at the entrance to a cave (likely their cave), placed the child in the hole on his or her right side with knees drawn toward the chest.

After proper analysis of the surrounding soil and the decomposition that has taken place in the pit over the years, the archaeologists believe the child, now nicknamed Mtoto, was intentionally buried shortly after death.

The modern human DNA evolved sometime between 71,000 and 51,000 BCE. Imagine that. A human baby born today, and a human baby born in 60,000 BCE have nearly indistinguishable DNA. There are differences but essentially humans are the same now as they were then. The popular website 23andme.com focuses on 23 changes in DNA that signify your ancestors recent migration. 23andMe.com, ancestry.com, and many others identify differences for their customers. Finally, the medical community is currently in an intense wave of identifying genetic differences that lead to medical problems with the idea of early diagnosis, prevention, and through the use of mRNA correction.

Through mtDNA sequencing, we currently believe the most recent common ancestor of all the Eurasian, American, Australian, Papua New Guinean, and African lineages dates to between 73,000 and 57,000 years ago.

The Venus of Hohle Fels is a 2.4″ figurine made of wooly mammoth ivory that was unearthed in 2008 in Hohle Fels, a cave near Schelklingen, Germany. It was pieced together from six pieces found in a cluster, about 10 feet below ground, and about 60 feet from the cave entrance. The left arm and shoulder are still missing. In place of a head, a carved ring protrudes indicating the sculpture was likely worn as a pendant. Using radiocarbon dating, the figurine is dated to between 38,000 and 33,000 BCE.

Humans used bone and ivory needles like these about 28,000 BCE to sew warm, closely fitted garments. These bone needles are from Xiaogushan, Liaoning Province, China, and are dated to about 28,000 to 21,000 BCE.

How old is Jericho? Jericho has been continuously inhabited since at least the 90th century BCE. That makes it at least 50 centuries older than 4000 BCE which is about the time the Bible indicates God created the Earth.

From 6500 to 4000 BCE, the Sumer civilization increased in social polarization. For example, central houses in the settlements became bigger. This early Sumer culture is characterized by large unwalled villages with multi-roomed rectangular mud-brick houses. The village featured public buildings including temples and centralized government. They had fine quality greenish colored pottery decorated with geometric designs in brown or black paint. Their known tools that survived the test of time included sickles made of hard fired clay, stone, and metal and the use of ploughs. Villages included craftspeople, potters, weavers and metalworkers, but the bulk of the population were farm workers.

The known Sumerian city-states written history goes back to before 2700 BCE, and starting about 2300 BCE the records are fairly complete.

The Jiahu gudi is the oldest known musical instrument from China. This 8,000 year old flute dates back to circa 6,000 BCE. Gudi literally means “bone flute”.

The earliest known man made glass dates back to circa 3500 BCE and to Egypt and Eastern Mesopotamia. Discovery of glassblowing around 1st century BC was a major breakthrough in glass making.

The Xia Dynasty is the first documented government of ancient China. The first to adopt dynastic succession. In modern times, it was regarded as a myth created later by Chinese historians, but 20th-century excavations uncovered sites which corresponded to descriptions in earlier historians’ accounts. This fact is an important lesson on understanding how little survived the test of time. How much we will never know about the true progress of humans over our first 100,000 years. 

The legendary story of Noah’s flood occurred in the year 2348 BCE if you believe Ussher’s biblical timeline he made up in 1654. However, this flood myth is clearly based on the Sumerian flood story documented in the Epoch of Gilgamesh circa 2100 BCE.

The Epoch of Gilgamesh is regarded as one of the earliest surviving notable literature. I think it is interesting to note that the first section of the Epoch of Gilgamesh refers to a time span of 241,200 years prior to the great flood. To me, it is interesting that around the proposed date of the great flood, the people authoring it thought the Earth was at least 241,200 years old. The first section of the Epoch of Gilgamesh lists eight kings who ruled over the five cities of Eridu, Bad-tibiru, Larag, Zimbir and Shuruppag. The section ends with the line “Then the flood swept over.”

The Proto-Sinaitic alphabet is considered the earliest trace of alphabetic writing and the common ancestor of both Ancient South Arabian script and the Phoenician alphabet. The ancient South Arabian script evolved about 900 BCE which continued to evolve into today’s Modern South Arabian languages. The Phoenician alphabet evolved into the Greek alphabet and all of today’s Western alphabets.

The Rigveda, Sanskrit for “praise knowledge”, is a collection of sacred texts of Hinduism first written down between 1700 and 1100 BCE. The sounds and texts of Rigveda have been orally transmitted since at least circa 2000 BCE. It discusses cosmology, praises deities, and covers philosophical questions including…

• 1.164.34: “What is the ultimate limit of the earth?”, “What is the center of the universe?”, “What is the semen of the cosmic horse?”, “What is the ultimate source of human speech?”;
• 1.164.34: “Who gave blood, soul, spirit to the earth?”, “How could the unstructured universe give origin to this structured world?”;
• 1.164.5: “Where does the sun hide in the night?”, “Where do gods live?”;
• 1.164.6: “What, where is the unborn support for the born universe?”;
• 1.164.20 is a parable of the Body and the Soul.

The other three books of the Veda were written centuries later:

• Yajurveda, circa 1000 BCE
• Samaveda, circa 1000 BCE
• Atharvaveda, circa 700 BCE

The Phoenician alphabet is a direct continuation of the Proto-Canaanite script circa 1300 BCE. Starting about 900 BCE, the Phoenician alphabet thrived and was adapted by others. It evolved into use by many languages including Greek, Old Italic and Anatolian scripts. These early uses of the alphabet evolved into the alphanumeric alphabet. 

The Greek philosopher and mathematician Pythagoras was born in Ancient Greece on the island Samos which is about a mile off the coast of modern Turkey. History looks at Pythagoras as an educator and philosopher as well as a cult leader. He discovered the musical octave, used deductive reasoning, and embraced an early version of forms which was a stepping stone to Plato’s forms. His early theories on math as the answer to the universe are elementary and off course, but these first attempts led the path for future mathematicians to explore. He is most remembered for his Pythagorean theorem which states the square of the length of the hypotenuse of a right triangle equals the sum of the squares of the lengths of the other two sides

As a cult leader, he spent his life brainwashing anyone who would follow him. Like Jesus, he said he was the son of God. His cult had strange rules including that you had to be silent for five years before you could join. A clever trick that meant only true believers who would not tell others of the crazy could get in. The crazy ran deep. You must spit on your finger clippings. You cannot urinate toward the sun. They sacrificed an ox whenever they proved a mathematical formula.

Pythagoras never wrote anything down or at least none of his writings survived so we have to rely on what others say he said and did, but we’re likely never to know what was Pythagoras’ pure ideas from the evolved or altered ideas of later writers. 

Some of my favorite translated sayings attributed to Pythagoras:

• Reason is immortal, all else mortal.
• There is geometry in the humming of the strings, there is music in the spacing of the spheres.
• As soon as laws are necessary for men, they are no longer fit for freedom.
• Do not say a little in many words but a great deal in a few.

Socrates was a Greek philosopher and is frequently credited as the founder of Western philosophy. He left no writings, but his student Plato documented his philosophy.

Some of my favorite translated sayings attributed to Socrates:

• Enjoy yourself — it’s later than you think.
• He who is not content with what they have will not be content with more.
• Do not praise someone wealthy until you known how they employ it.
• We should hear and see more than we speak.
• False words are not only evil in themselves, but they infect the soul with evil.
• He is rich who is content with the least.
• Once made equal to man, woman becomes his superior.

The earliest known magnification dates back to the first century. These simple early magnification devices consisted of using natural crystals or a glass globe filled with water. It is reasonable to assume the use of natural crystals for magnification was around for many thousands of years. One possible specimen is the Nimrud lens dating back to 750 BCE.

Although man-made glass was in common use about 3500 BCE, eye glasses would have to wait about 4,500 years later. Eye glasses were invented in the 13th century. A few centuries earlier, a reading glass was in common use. A piece of glass you set on a page of text to magnify the letters well enough to read easily.

These early devices provided a max of about 2x, or perhaps 3x, magnification. The microworld of cells and large bacteria would have to wait for the invention of good quality microscopes about 1630. The nanoworld of smaller bacteria, viruses, proteins, and molecules would have to wait for the invention of the electron microscope in 1931.

• The world is a book and those who do not travel read only one page.
• Right is right even if no one is doing it; wrong is wrong even if everyone is doing it.
• There is no saint without a past, no sinner without a future.

Spaces between words started circa 1000 CE because those copying texts found it easier and faster to copy if they introduced spaces between words. The 1215 Magna Carta is a good example of this quality of writing which included word-spacing, uppercase, and lowercase, but no punctuation, nor paragraphs. 

In 1905, radiometric dating was discovered. It is a method used to date rocks and other objects based on the known decay rate of radioactive isotopes. This technique is used to date rocks. Paleontologists regularly order discoveries in chronological order and estimate their age. Knowing the age of rocks allows paleontologists to assign known values to rocks and fossils to firm up the known historical calendar.

In 1946, Willard Libby created the method for dating organic materials by measuring their content of carbon-14, a newly discovered radioactive isotope of carbon. This dating technique provides objective age estimates within a few decades for carbon-based objects that originated from living organisms.