The following three paragraphs and illustration are from a brochure that I read recently. Its title is, The Origen of Life―Five Questions Worth Asking*:
"In fact, more than half of all the major divisions of animal life seem to have appeared in a relatively short period of time. Because many new and distinct life forms appear so suddenly in the fossil record, paleontologists refer to this period as 'the Cambrian explosion.' When was the Cambrian period?
"Let us assume that the estimates of researchers are accurate. In that case, the history of the earth could be represented by a time line that stretches the length of a soccer field (1). At that scale, you would have to walk about seven eighths of the way down the field before you would come to what paleontologists call the Cambrian period (2). During a small segment of that period, the major divisions of animal life show up in the fossil record. How suddenly do they appear? As you walk down the soccer field, all those different creatures pop up in the space of less than one step!
"The relatively sudden appearance of these diverse life forms is causing some evolutionary researchers to question the traditional version of Darwin’s theory."
Confirmation bias (the tendency of people to favor information that confirms their beliefs or hypotheses) might cause a creationist to interpret those three paragraphs to support his belief that the diversity of life that we see today all appeared during a relatively short period of time.
Someone who recognizes the fossil evidence―that species of life have appeared and disappeared for over 3 billion years (and that 99.9% of all species that have ever existed are now extinct)―might be left scratching his head.
When the brochure says that "all those different creatures" ("the major divisions of animal life") 'popped up' during a small segment of the Cambrian period, are you left with the impression that fish, insects, amphibians, reptiles, birds, or mammals appeared during the relatively-short Cambrian period?
Nothing could be further from the truth.
In fact, the brochure doesn't say that at all. (So, creationists and evolutionists alike can breathe a sigh of relief.) The point is being made that perhaps all life did not descend from a single ancestor. That does not question whether or not life is evolving...only whether or not all life (on earth) had one single source.
The facts presented in that section of the brochure are pretty accurate, but not intended to be complete. So, for those who prefer the big picture, here is "the rest of the story":
In the illustration, the length of the soccer field represents the approximately 4.54 billion years that the earth has existed. The Cambrian period is shown by the red line that runs through the right-side penalty area...starting about 4 billion years after the earth first formed, ending about 485 million years before today. The thickness of the line represents the length of the Cambrian period...about 60 million years.
Fossil evidence shows that about 3 billion years before the Cambrian period started, prokaryotes (living organisms whose cells lack a membrane-bound nucleus) existed in the sea. From then until the Cambrian period, cyanobacteria came into existence, then complex cells (eukaryotes), then multicellular life.
As the brochure correctly states, during the Cambrian period "the major divisions of animal life show up in the fossil record." What it does not say is that those "major divisions of animal life" were "bacteria", "archaea", and "eucaryota"...nothing more. By the end of the Cambrian period, the most advanced animals that existed out of "all those different creatures [that popped up] in the space of less than one step" were trilobites.
(Virtually all life was still in the sea. For the first 3 billion years that life existed, it couldn't survive on dry land, because the ozone layer was not yet sufficiently developed to shield ultraviolet rays from the sun.)
Fish (the first vertebrates) started appearing about 45 million years after the Cambrian period. Millipedes...over 100 million years after. Amphibians, primitive insects, and primitive ferns―the first plant with roots―more than 200 million years after. Then reptiles (250 million years after) and mammals (more than 300 million years after).
"A little learning is a dangerous thing."―Alexander Pope (1688 – 1744)
* © 2010 Watch Tower Bible and Tract Society of Pennsylvania
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"In fact, more than half of all the major divisions of animal life seem to have appeared in a relatively short period of time. Because many new and distinct life forms appear so suddenly in the fossil record, paleontologists refer to this period as 'the Cambrian explosion.' When was the Cambrian period?
"Let us assume that the estimates of researchers are accurate. In that case, the history of the earth could be represented by a time line that stretches the length of a soccer field (1). At that scale, you would have to walk about seven eighths of the way down the field before you would come to what paleontologists call the Cambrian period (2). During a small segment of that period, the major divisions of animal life show up in the fossil record. How suddenly do they appear? As you walk down the soccer field, all those different creatures pop up in the space of less than one step!
"The relatively sudden appearance of these diverse life forms is causing some evolutionary researchers to question the traditional version of Darwin’s theory."
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| The soccer field illustration from pages 22-23 of the brochure. |
________________________________________________________________________
Confirmation bias (the tendency of people to favor information that confirms their beliefs or hypotheses) might cause a creationist to interpret those three paragraphs to support his belief that the diversity of life that we see today all appeared during a relatively short period of time.
Someone who recognizes the fossil evidence―that species of life have appeared and disappeared for over 3 billion years (and that 99.9% of all species that have ever existed are now extinct)―might be left scratching his head.
When the brochure says that "all those different creatures" ("the major divisions of animal life") 'popped up' during a small segment of the Cambrian period, are you left with the impression that fish, insects, amphibians, reptiles, birds, or mammals appeared during the relatively-short Cambrian period?
Nothing could be further from the truth.
In fact, the brochure doesn't say that at all. (So, creationists and evolutionists alike can breathe a sigh of relief.) The point is being made that perhaps all life did not descend from a single ancestor. That does not question whether or not life is evolving...only whether or not all life (on earth) had one single source.
The facts presented in that section of the brochure are pretty accurate, but not intended to be complete. So, for those who prefer the big picture, here is "the rest of the story":
In the illustration, the length of the soccer field represents the approximately 4.54 billion years that the earth has existed. The Cambrian period is shown by the red line that runs through the right-side penalty area...starting about 4 billion years after the earth first formed, ending about 485 million years before today. The thickness of the line represents the length of the Cambrian period...about 60 million years.
Fossil evidence shows that about 3 billion years before the Cambrian period started, prokaryotes (living organisms whose cells lack a membrane-bound nucleus) existed in the sea. From then until the Cambrian period, cyanobacteria came into existence, then complex cells (eukaryotes), then multicellular life.
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| An example of a trilobite fossil |
(Virtually all life was still in the sea. For the first 3 billion years that life existed, it couldn't survive on dry land, because the ozone layer was not yet sufficiently developed to shield ultraviolet rays from the sun.)
Fish (the first vertebrates) started appearing about 45 million years after the Cambrian period. Millipedes...over 100 million years after. Amphibians, primitive insects, and primitive ferns―the first plant with roots―more than 200 million years after. Then reptiles (250 million years after) and mammals (more than 300 million years after).
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| "All those different creatures [that] pop up in the space of less than one step" refers only to a group of extinct marine arthropods. |
"A little learning is a dangerous thing."―Alexander Pope (1688 – 1744)
* © 2010 Watch Tower Bible and Tract Society of Pennsylvania
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