Saturday 20 June 2009

“Human Evolution On Trial – A Case For The Defence" - Part 1 - Terry Toohill

A Case For The Defence


Following private correspondence with author Terry Toohill, I've agreed to serialise his book
“Human Evolution On Trial – A Case For The Defence" here at Remote Central, in the hope that not only will readers be interested to read what he has to say, but will also be prompted to add comments of their own, on what is a suitably detailed and well-researched set of chapters charting the author's take on what he also refers to as “From Apes Until today – A Case In Defence Of Human Evolution”.

I have been advised by Terry that the text is subject to copyright, as it has been placed in the Alexander Turnbull Library of New Zealand, and although I don't have details at the moment, copies may be available for purchase from the author. But for the time being, it's free to read here, so I hope readers find this a worthwhile and thought-provoking book, further instalments of which are scheduled to appear on this blog over the coming weeks.

I should also add as the usual disclaimer that the views and opinions contained therein are solely those of the author, and that he alone is responsible for the text and the details it contains, as he is the sole author - I hope that covers it.

So without further ado, here's an introduction from Terry Toohill, and my thanks to him for allowing his work to be published here at remote central.

"This extract is from partway through an account I have compiled on our evolution. My basic theme is that our cultural beliefs always influence how we interpret all phenomena. Because Judeo-Christian beliefs have been with us so long they have fundamentally influenced how we view the world. This has hampered an understanding of our origin as a species. I show that when we eliminate a biblical perspective any problems in our complete understanding of evolution disappear. On the other hand once we understand our evolution we easily see the history that lies behind stories in the Old Testament. I have divided the account into five parts.

In Part I, “Beginning - The Present”, I explain how genes work. I show how, in practice, populations or whole species can be simply regarded as a collection of genes in various proportions. I point out we could even say that each individual gene travels through a population on its own independent wave.

In Part II “Migration – The Past” I use what we know of New Zealand’s history and prehistory to show how recent human evolution provides evidence in support of the idea.

In Part III, “Biological Rules - Knowledge” I start with the short summary of the history of the earth presented here. I next look at the development of geology and then the complex question of what is a species. I show that any definition we attempt is inadequate. I then return to how biological evolution works.

Part IV “Wandering – Becoming Human” starts with our ape ancestors. I then look at the progressive development of Stone Age technology. I show that in some ways we can regard technology as evolving in a similar way to organic evolution; diversification, then hybridising followed by selection. Remaining chapters in this part follow and explain our ancestors’ biological development through various named species from Homo erectus to Neanderthals and modern humans. I argue that the ready acceptance of a mtEve single ancestor derives primarily from the influence of our Judeo-Christian background.

In Part V, I simply follow the course of modern human evolution until written records are able to tell us the historical situation in each region. I show all our culture, our knowledge, our beliefs and our skills are the result of a similar mixing, or “interbreeding”, followed by selection or culling. As a last point I compare human migration through islands in the Mediterranean Sea to that through islands in the Pacific Ocean. Finally I use my ideas to explain many stories in the Old Testament.


Preface - A Brief History of the World


Time



History needs dates and so I had better first provide a framework for all the 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 I’m sure you’ll find it useful to refer to it when necessary. 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 far end of the chart, 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’ll start with a human generation of twenty-five years and keep doubling the time.


For convenience we’ll begin at 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, and so on.


Doubled again takes us back to 1800 AD when we each have over two hundred and fifty ancestors in our individual pedigrees. 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. There is no doubt Maori had become 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 the temporary disruption of the Roman Empire 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. We are also at about the time of Ramesses III of Egypt and the migration of the Sea People through the Mediterranean Islands, what we might call 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.


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). The keeping of records through the use of writing probably began around this time. And Archbishop Ussher believed the earth had been created then. People in the Balkans were working copper (James 1991) and the Austronesian-speaking people began their expansion from Taiwan. 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. The Gravettian people probably used the same route as the Corded Ware people were to take 18,000 years later. 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. 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, or
Homo sapiens, are said to have left Africa by the time we double again to 100,000 years ago. They may have been held up in the Middle East because Neanderthals (Homo neanderthalensis) keep popping up there over the next 50,000 years.


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.


By 800,000 years ago the species
Homo erectus had probably reached the geographical extremes of their range. It was not until four divisions more recently that humans were able to expand further, into Australia. We’ll return to this summary in a while 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.

0: 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

200: The Industrial Revolution began and Europeans started moving into Australia and New Zealand

400: Time of Queen Elizabeth I. Europeans off learning about the world. Bruno executed

800: Maori in New Zealand by this time. Inquisition established

1600: Decline of Roman Empire, Anglo-Saxons into England

3200: About the time of Rameses III of Egypt and the Kingdom of Israel. Lapita pottery people to Tonga and Samoa.

6400: 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 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: Primitive life on Earth

4160 million: Round about the beginning of the Earth


Now to carry on:


Double again to 1.6 million years ago and we have
Homo erectus beginning their expansion. We should probably call them the first humans. 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 Africa 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 in Chad (Lemonick and Dorfman 2002).


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 is 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. We can use evidence from these and many other species to prove what a friend has called the wave theory of genetic, cultural and technological evolution. This theory is able to help us interpret the evidence for our evolution from apes until today. So do we need to go further back if we are concerned just with this? But I’m on a roll and for now I’ll just keep doubling the time until I reach the beginning of the earth.


Apes seem to 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. 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 whether or not we evolved from apes.


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 there have 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). 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 is 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 actually at the core of the debate between the “spread origin” and “single origin” theories of human evolution. You will be able to decide for yourself which is the most likely theory as we examine 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."


References



Attenborough, David (1987) The First Eden. Guild, London.

Corfield, Richard (2001) Architects of Eternity.
(UK/US) 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.
(UK/US) 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, Wellington

Tudge, Colin (1996) The Time Before History.
(UK/US) 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.

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