Human Evolution on Trial - 'Time'
History needs dates and so the defence had better provide a framework for all this evidence. To understand the lengths of time involved for various events during the earth’s history try this summary. It is an exponential time scale. There is a condensed version in the form of a chart starting a few pages ahead and you will be able to refer back to it when necessary during the rest of the trial. But first of all I’ll explain it.
The most recent events are at the top, or beginning of the chart, as they are in geological strata or layers. The older, or lower, layers are compressed, also as they are in geological strata. To read it in the order things happened you have to start at the bottom, or at the end of the chart, (p.88) but you can start anywhere. As you move back in time, or down the list, each division covers the same length of time as everything before it (or above it). As you move up the column towards the present each division halves the time between then and today. The chart has the advantage of being close to how we actually view time because as Gohau (1991) writes “every history favors the present over the past, if only because of the unequal amount of data available for the two”. I have juggled the figures a little in places to produce more significant dates but it still basically doubles all the way.
To make it relevant for humans I will start with a human generation of twenty-five years and keep doubling the time. For convenience we’ll begin at the year 2000 AD. Twenty-five years takes us back to 1975. Fifty years ago it was 1950, soon after the end of the Second World War. Double it again and we are back 100 years, the beginning of the twentieth century.
Doubled yet again takes us back to 1800 AD when we each have over two hundred and fifty ancestors in our “Pedigree” [Ancestry]. The steam engine had just come into general use (Fyrth and Goldsmith 1965) and so we could use this date to mark the beginning of the Industrial Revolution and the beginning of geology.
Double again to four hundred years ago and we are about the time of the death of Queen Elizabeth I of England (March 1603). We are well into the time of European exploration, exploitation and expansion around the world and the beginning of the latest round of extinctions. We are nearing the time of a million ancestors each. The invention of both the telescope and the microscope around this time meant science could begin. Both Lucilio Vanini and Giordano Bruno were burnt at the stake for their beliefs. Archbishop Ussher calculated the earth had been created in 4004 BC, near enough to 6400 years ago.
Eight hundred years takes us back to just 1200 AD though. You saw in “Change” [Destruction] there is no doubt Maori were well established in New Zealand by this time. The Crusades were well under way and Genghis Khan took control of the Mongols.
Sixteen hundred years ago marks the withdrawal of the Roman Empire from much of Western Europe, although an argument can be made that “The West” is a continuation of it. The Anglo-Saxon movement into England coincided with its temporary disruption in Britain. Human expansion beyond Samoa into Eastern Polynesia was well underway.
Double 1600 years to 3200 years ago (1200 BC) and people using Lapita pottery were about to reach Tonga and Samoa (“Pacific Population” [Lapita]). We are also at about the time of Ramesses III of Egypt and the migration of the Sea People through the Mediterranean Islands, “The Last Point” of the human star. It may also be the time of any kingdom of Israel in the Middle East under David and Solomon although not all people regard all these events as being contemporary. I’ll return to this in “Culture” [Evolution of a Religion].
Double again to 6400 years ago (4400 BC) and we are at about the beginning of cities in the Tigris and Euphrates River valleys (Mesopotamia) in what is now Iraq. Much older towns have been found just outside the region though (for example at Jericho). Record-keeping through the use of writing probably began around this time. And Archbishop Ussher believed the earth had been created then. Balkan people were working copper (James 1991) and the Austronesian-speaking people began their expansion from Taiwan (“Polynesian Origins”). People with the Linear Pottery or Danubian culture were moving into Europe.
If we double again we reach 12,800 years ago but we’ll round the date to 12,500. We are near the end of the ice age and the beginning of human movement into the extreme end of the Northwest European point of the human star and into the American sub-point. The first steps towards farming were probably also made at this time both in the Middle East (the Fertile Crescent) and in Southeast Asia (the Hoabinhian culture).
Double the time again and we have 25,000 years ago, about the time people with the “Gravettian” stone-age culture moved into Western Europe from east of the Carpathian Mountains, from Southern Russia. Modern humans finally replaced the Neanderthals, probably at least partly through the formation of hybrids (“Neanderthals et al” [Aurignacian and Mousterian]). The Gravettian people probably used the same route the Corded Ware people were to take 18,000 years later (see “Indo-Europeans” [Mingling]). The jury will meet the Gravettian again several times, especially in Part V. African and European cattle separated at about this time.
About 50,000 years ago humans known as Cro-Magnon started moving into Europe, most likely from the southeast via Turkey and Greece (“Out of Africa” [Cro-Magnon]). They introduced the “Aurignacian” technology. At the opposite side of the human star people were able to move “Into Australia” for the first time.
Fully modern humans (Homo sapiens) are said to have left Africa by the time we double again to 100,000 years ago. They seem to have been held up in the Middle East because Neanderthals (Homo neanderthalensis) keep popping up there over this 50,000 years. We’ll return to the period from here to the present in Part V. In the meantime we’ll keep going back.
200,000 years ago we have Homo heidelbergensis in Europe (the first fossils of it were found near Heidelberg). Neanderthals and modern humans both presumably developed from this species (possibly with some input from earlier Homo erectus). Neanderthals’ culture is called “Mousterian” and involved the “Levallois” technique of working stone.
The Levallois developed some time between 200,000 and 400,000 thousand years ago and 400,000 years ago is about when Homo heidelbergensis developed, presumably from some sort of Homo erectus. The defence will present evidence from this period in Part IV (“Technology” and “Species or Not”). We’ll return to this summary of “Time” over the page but now is a convenient place for us to have a rest and for me to show you the chart.
A Short History of the Earth
Years ago Significant Event
2000 AD The New Millennium
25 One generation, back to 1975. I left the Manawatu and returned to Northland
50 End of Second World War (roughly). I was born (a little less roughly)
100 Beginning of the twentieth century. Humans found they could fly after all
The Industrial Revolution began and Europeans started moving into Australia and New Zealand
Time of Queen Elizabeth I. Europeans off learning about the world.
Maori in New Zealand by this time. Inquisition established
Decline of Roman Empire, Anglo-Saxons into England
About the time of Ramesses III of Egypt and the Kingdom of Israel. Lapita pottery people to Tonga and Samoa
Cities developing in the Middle East and possibly Egypt. Linear pottery-bearing and Austronesian-speaking people begin their expansion
12,500 End of ice age. Beginning of farming and Hoabinhian culture. Humans able to enter what I call the American subpoint of the human star
25,000 In Europe the Gravettian stone tool culture moved in from the northeast
50,000 Aurignacian stone tool culture into Europe from the southeast. (Cro-Magnon man). First humans into Australia
100,000 Human expansion out of Africa. They and Neanderthals alternate in the Middle East for half the time between today and then.
200,000 Mousterian (Neanderthal) stone culture and evidence of controlled use of fire in Europe.
400,000 Evolution of Heidelberg Man and Levallois stone working.
800,000 Homo erectus reaches maximum distribution around the Earth.
1.875 million Evolution of Homo erectus in Africa and Asia. Ice ages well established.
3.75 million Good fossil evidence for Australopithecus (Lucy).
7.5 million Roughly time of split between humans, chimps and gorillas. Three-toed horses out of America.
15 million Africa became jammed into Asia and Europe. Ancestors of modern apes able to move between these continents.
30 million Mid-Oligocene geological epoch. Apes separated from monkeys during this period.
65 million End of the Cretaceous geological period and the dinosaurs. Continents started splitting and age of mammals began. Monkeys already developing.
130 million Beginning of Cretaceous (end of the Jurassic period). The Cretaceous fills half the time between today and then.
260 million Beginning of the Permian geological period. Most of the oldest rocks in New Zealand were laid down over the period from the Permian to the end of the Jurassic. Again this took up half the time between today and then
520 million End of the Cambrian geological period. The first mass extinctions we are aware of.
1040 million Possibly an ice age.
2080 million So long ago I can’t remember what happened here.
4160 million Round about the beginning of the Earth.
Now to carry on:
As I said by 800,000 years ago the species Homo erectus had probably reached the geographical extremes of their range. You saw it was not until four divisions more recently that humans were able to expand further, “Into Australia”.
Double again to 1.6 million years ago and we have Homo erectus beginning their expansion. “First Humans” will be about these people. The latest series of ice ages had started a little before this time. There have been up to twenty cycles of extreme cold followed by periods as warm as or warmer than today. The climate had actually already been steadily cooling for more than 30 million years before this though. The period of the ice ages is known as the “Pleistocene geological epoch”. The beginning of the Pleistocene, about two million years ago, also marks the end of the Tertiary and the beginning of the Quaternary geological period.
Homo erectus evolved more than 1.7 million years ago but I’ll use 1.875 million years. When that is doubled it comes up 3.75 million years ago. From about this date there is good fossil evidence in “The First Point” for presumed Homo erectus and human ancestors, in the form of “Lucy” and other Australopithecus species (Johanson and Edey 1982). Some genetic evidence has been interpreted as showing humans, chimpanzees and gorillas may have finally separated as recently as this date (Gribbin and Cherfas 2001). Various species of Equus and camels moved out of North America also about this time.
Doubled again is 7.5 million years and three-toed horses moved out of North America. This is also about the earliest time given for the split between chimpanzees and humans, although gorillas may have separated even earlier. A fossil of this age that could well lie on the line to humans has recently been found just outside “The First Point”, in Chad (Lemonick and Dorfman 2002). I’ll return to the evidence for the evolution of various human types, and their technology and culture, in Parts IV and V but I am on a roll and for now I’ll just keep doubling the time until we arrive at the beginning of the earth.
Fifteen million years ago, in the middle of the Miocene geological epoch, Africa became jammed up against Asia and Europe (Attenborough 1987). This allowed the ancestors of the modern (or brachiating) apes to move between Africa and Asia (brachiating is the ability to swing or hang from branches by your arms). In fact it’s possible the ancestors of the present African apes (including humans) actually moved into Africa from Asia (Gribbin and Cherfas 2001). The gibbons may have separated from the rest of the ape line as early as fifteen million years ago. They have become particularly effective brachiators. The orangutan separated eight to ten million years ago.
Double again and we are in the middle of the Oligocene geological epoch, at 30 million years ago. Three-toed horses appeared in North America and the ancestors of deer and giraffes separated from other ruminants during this period. Camels and llamas had already parted from them. The defence will use evidence from these and many other species to prove the wave theory in the remainder of Part III. Apes may have separated from monkeys during this period. Apes diverged into many species most of which (apart from some of the later brachiating ones) eventually became extinct.
During the Oligocene the continents were at their lowest altitude, having been eroded down since well back in the Cretaceous period. The climate was very warm and seas were at their highest. From the Oligocene until the present the continents start bumping into each other again. Mountains rise and the sea is able to sink into deeper ocean basins. This period also marks the beginning of the climate cooling that led ultimately to the latest series of ice ages. The immediate cause of the cooling was probably the opening of the gap between Australia and Antarctica. This allowed the southern circum-polar current to develop (Stevens 1985).
Double again and we have 60 million years but we’ll make it 65 million years, which marks the end of the Cretaceous geological period and the beginning of the Tertiary geological period. It also marks the extinction of the dinosaurs and beginning of the age of mammals. Some people believe the dinosaurs didn’t actually become extinct. Small versions that had evolved feathers, probably to keep warm, evolved into birds.
The Cretaceous itself in fact lasted about 65 million years and so the Cretaceous began 130 million years ago. This earlier date marks the end of the Jurassic period and the beginning of another breakup of continents. Virtually all the sea floor on earth is younger than this date and most of it is younger than half this age (Jones 2000). The lowering of mountain ranges by erosion and the gradual filling of sea floor with the sediment during the sixty-five million years of the Cretaceous eventually had the effect of raising sea levels and partially flooding the continents.
The gradual isolation and size reduction of the continents during the Cretaceous period and consequent climate and environmental change may have had as much to do with the eventual extinction of the dinosaurs outside North America as did the asteroid collision. Dinosaur extinction was actually very protracted; at least hundreds of thousands of years (Jones 2000). And possibly millions but humans like the idea of catastrophes. In fact many people hope the world is going to end soon.
The massive eruption of volcanoes on the Deccan plateau of India near the end of the Cretaceous would have contributed to the dinosaur extinction and could be partly responsible for the layer of heavy metals found in sediments from 65 million years ago throughout the world. Although Richard Corfield (2001) does mention this possibility he seems to suggest the idea has been rejected largely because of political and funding considerations. He actually offers no evidence to dispute it. Most mass extinctions have coincided with large volcanic eruptions though (Wade 2001).
The ancestors of monkeys and lemurs had separated from other mammals at some time during the Cretaceous, probably along with the development of flowering plants, especially trees (Tudge 1996). Flowering plants appeared in the mid-Cretaceous and the evolution of grass may have been the final straw, so to speak, for the dinosaurs. Grasses didn’t actually reach their major expansion until more recently though (at the beginning of the Miocene epoch about 25 million years ago) and ruminants or cud-chewing animals seem to have started developing a little before that time (“Evolution” [Ruminants]). The expansion of grassland was also responsible for the development of horses.
Double the time again and we get 260 million, the beginning of the Permian period. The Permian is actually in the Paleozoic geological era but the Paleozoic ends with the end of the Permian, about 235 million years ago. Great volcanic eruptions and a series of ice ages similar to the ones the earth has just been through mark the end of the Permian. But the continents were in much different positions than they are today. The time also marks easily the greatest mass extinction event we are aware of. It makes the extinction event at the end of the Cretaceous (which included the extinction of the dinosaurs) look relatively minor, about number five on a list of severity.
Double again: 520 million is the end of the Cambrian period, marked by the extinction of much of the variety of life that had developed by that time. The Cambrian began about 570 million years ago with a huge explosion of life forms (Corfield 2001). Supporters of the Intelligent Design theory of evolution apparently believe this happened through a creation (Wells 2000, and Dembski and Kushiner 2001). Anyway whether it happened by creation or not is irrelevant to this case although arguments both for and against will no doubt be presented when “The origin of Life” comes to trial. I’m sure the wave theory will be able to help us interpret the evidence. Besides, do we need to go even this far back if we are concerned just with Human Evolution from apes until today? This could become an incredibly long story. But I’ve nearly reached the beginning.
1040 million years is in the Precambrian era and someone else can look for significance in that date but some evidence suggests complex life began about then (Wade 2001). Intelligent Design supporters presumably would say through another creation event. Until James Hutton’s time most geologists used the idea that there had been several “creations” to explain the fact that throughout the world rocks of the same age have similar collections of fossils, many of them not present in more recent levels (Gohau 1991 and see “Long Ago” [Geology]). Most early geologists believed each group of earlier life had been destroyed by catastrophes. There had been a series of beginnings. Others began to see a basic thread that indicated life had changed or evolved through the history of the earth.
We can see that the same old argument carries on in the conflict between creationists and evolutionists. The term creationist covers a huge variety of beliefs though. Some of them even accept evolution has occurred but that it has happened by design (Wells 2000, and Dembski and Kushiner 2001).
The preference of any individual to accept either gradual or sudden change (or even no change at all) as an explanation for the development of life on earth depends very much on what has been, or is, important in their own life. It’s difficult for us to imagine the world has ever changed more than it has over our own lifetime. We also carry many mythconceptions from our childhood. I believe the conflict between a belief in gradual or sudden change is at the core of the debate between the “spread origin” and “single origin” theories of human development (see “Conception”). You will be able to decide for yourself which is the most likely theory after examining the rest of the evidence.
2080 million years may be significant (perhaps the beginning of life itself) and the earth is said to have begun a little more than 4160 million years ago.
See next :: Human Evolution On Trial - Long Ago
Attenborough, David (1987) The First Eden. Guild, London.
Corfield, Richard (2001) Architects of Eternity. Headline Book Publishing, London.
Dembski, William and Kushiner, James (2001) Signs of Intelligence. Brazos Press, USA.
Fyrth, H. J. and Goldsmith, M. (1965) Science History and Technology Book 1. Cassell, London.
Gohau, Gabriel (1991) A History of Geology. Rutgers University Press, New Brunswick, USA.
Gribbin, John and Cherfas, Jeremy (2001) The First Chimpanzee. Penguin Books, England
James, Peter (1991) Centuries of Darkness. Jonathan Cape, London.
Johanson, Donald and Edey, Maitland (1982) Lucy. Warner Books, New York.
Jones, Steve (2000) Almost Like a Whale. Anchor, London.
Lemonick, Michael and Dorfman, Andrea (2002) Father of us All? Time, July 22nd.
Stevens, Graeme (1985) Lands in Collision. Science Information Publishing Centre,
Tudge, Colin (1996) The Time Before History. Scribner, New York.
Wade, Nicholas ed. (2001) The New York Times Book of Fossils and Evolution. The Lyon Press, New York.
Wells, Jonathan (2000) Icons of Evolution. Regnery Publishing, USA.