J. William Schopf
Autore di Cradle of Life: The Discovery of Earth's Earliest Fossils
Sull'Autore
J. William Schopf, a member of the Department of Earth and Space Sciences, the Molecular Biology Institute, and the Institute of Geophysics and Planetary Physics (IGPP) at the University of California, Los Angeles, is Professor of Paleobiology and Director of the IGPP Center for the Study of mostra altro Evolution and the Origin of Life. A Member of the National Academy of Sciences, the American Philosophical Society, and the American Academy of Arts and Sciences, he is the recipient of medals from the National Science Board, the National Academy of Sciences, and the International Society for the Study of the Origin of Life. He has also been awarded national book prizes for two edited volumes on life's earliest evolution, an Alexander von Humboldt Senior Research Prize, and two Guggenheim Fellowships. mostra meno
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setnahkt | Nov 21, 2021 |
setnahkt | Nov 21, 2021 | 
Review of: Life in Deep Time: Darwin’s “Missing” Fossil Record, by J. William Schopf
by Stan Prager (5-5-19)
As a reader, some of my most serendipitous finds have been plucked off the shelves of used bookshops. Such was the case some years ago with Cradle of Life: The Discovery of Earth’s Earliest Fossils, by J. William Schopf, a fascinating account of how the author in 1965 was the first to discover Precambrian microfossils of prokaryotic life in stromatolitic sediments in Australia’s Apex chert dated to 3.5 billion years ago, the oldest confirmed evidence for life on earth at the time. My 2017 review of Cradle of Life—nearly twenty years after it was first published—sparked an email exchange with Bill Schopf that later led to his sending me a signed edition of his most recent book, Life in Deep Time: Darwin’s “Missing” Fossil Record. He did not ask me to read and review it, but naturally I did.
In this work, Schopf—an unusually modest man of outsize accomplishment—typically credits good fortune rather than his own estimable talents, often emphasizing the centrality of teamwork in the pursuit of sound science, as well as frequently paying tribute to the notion that each discovery and its discoverers are after all “standing on the shoulders of the giants” that preceded them. A young grad student when he first got into the game, at seventy-seven the author now remains the most significant living survivor of those paleobiologists that devoted decades in an effort to identify and substantiate traces of the most ancient forms of life on the planet. He feels the clock ticking, and thus is strongly motivated by a desire to leave a record of the journey that led to such consequential discoveries now that most of his peers have passed on.
The result is Life in Deep Time, a curious book—actually something of a blend of three different kinds of books—that succeeds more often than not in its efforts, even if at times it can be an uphill climb for the general reader. It is first and foremost a memoir that dwells for a surprisingly long time on the author’s youth and upbringing, which can be awkward at times because of his decision to employ a third-person limited literary technique in the narrative, so that it is “Bill wondered about …” rather than “I wondered about …” Early on, the reader might grow a bit impatient as Bill negotiates high school, often under the disapproving glare of his father, an admirable man who nevertheless sets impossibly high standards for his son and is quite difficult to please. Yet, even then Schopf is ever the optimist, always grateful for that which goes his way, and treating that which does not as a valuable learning experience. Rather than being scarred from the travails of enduring a demanding parent, he seems to sit in awe of a father who sets challenges that are always another chalk-mark higher than Bill can grasp. Such circumstances for another might leave that child a substance abuser or a ne’er-do-well, but it simply inspires Bill Schopf to be the best-of-the-best, fully absent an uncontainable ego or an axe to grind.
Beyond memoir, the second focal point of the book recounts Schopf’s scientific achievements, while paying tribute to those he worked with, many of whom are little known or entirely unknown outside of the paleobiology community. Science, the author repeatedly underscores, is a team effort. While the ever-modest Schopf does not dodge the recognition he clearly deserves for his key contributions to the field, he makes certain that credit gets appropriately shared among mentors and colleagues and even assistants.
Schopf’s work has spawned controversy that sometimes spilled over into the public arena. In the first case, there was pushback on his remarkable find of those 3.5-billion-year-old microfossils. Peer-reviewed science upheld his claim, although a prominent rival paleobiologist continued to dispute it. In the second, Schopf was brought in by NASA in 1996 to evaluate the extraordinary if premature announcement that life had been identified in a Martian meteorite, which was trumpeted by scientists, politicians and the media. Schopf was skeptical, and subsequent careful research proved him correct. The author’s well-written examination of these controversies is both coherent and enlightening, although blemished a bit by the continued use of that third-person limited literary technique, which feels especially awkward as he answers his critics through the narrative.
Schopf’s greatest triumph was certainly his discovery of those ancient fossils in Australia’s Apex chert, detailed in Cradle of Life and revisited in Life in Deep Time. Modern science has established that the earth is a little more than 4.5 billion years old, but in the mid-nineteenth century, when Charles Darwin devised his theory of evolution, no one could be sure what the true age of the planet was, although most scientists knew it was far older than the six thousand years that theologians claimed. In his groundbreaking 1859 treatise, On the Origin of Species, Darwin estimated that the erosion of England’s Sussex Weald must have taken some 300 million years, but he was taken to task on this by the famed Lord Kelvin, who publicly scolded that the earth could not possibly be older than 100 million years. Whatever the actual number, Darwin was deeply troubled because the process of natural selection that he envisioned would take much, much longer in order for higher life forms to evolve. In the century that followed Darwin, greater scientific sophistication established the true age of the earth with greater specificity, but it turned out that identifying the planet’s earliest life forms proved quite elusive. This is because traces of these unicellular organisms lacking a membrane-bound nucleus—the prokaryotes that include Archaea and Bacteria—can be maddeningly difficult to identify, and often actually appear to be inorganic remains with strikingly similar characteristics. A famous false positive in this venue set paleobiology back for many decades. As a result, even as late as 1965, Schopf’s find of 3.5-billion-year-old microfossils of prokaryotic life proved controversial, although eventually gained full acceptance by the scientific community.
The science behind all this is remarkably complex, and that is the third focus in Life in Deep Time, a welcome addition for those comfortable with textbooks on paleobiology, but often inaccessible to the general reader. I am trained in history rather than science, so I found some challenging moments in Cradle of Life that had me re-reading a paragraph or two, but much of it was indeed comprehensible to me as a non-scientist, which is not always the case with the final section of Life in Deep Time, which casually includes sentences such as this one:
“By this time, Bill had gained sufficient knowledge of the chemistry of kerogen, the coaly carbonaceous matter of which ancient microscopic fossils are composed, that he imagined that if the dominating polycyclic aromatic ring structures of the fossil kerogen were irradiated with an appropriate wavelength of laser light, they too would fluoresce and produce the images he sought.” [p186]
Material like this is certainly not impenetrable to an educated reader, but long discourses in this vein can lose a wider audience not schooled in paleobiology. Perhaps this content, although critical to scientists reading the book, might have been better placed in the appendix so as not to lose the flow of an otherwise engaging narrative.
While portions of Life in Deep Time may be difficult to navigate for the general reader, I would nevertheless recommend it. Bill Schopf is a remarkable man, a great scientist and a fine writer. The various threads of the tale he relates here add up to a storied saga of the evidenced- based search for the earliest life on the planet, as well as that of the distinguished if often otherwise anonymous men and women who were responsible for marking one of the greatest milestones in recent scientific history. The voice of Bill Schopf is a humble yet commanding one: it deserves to be heard.
[My review of: Cradle of Life: The Discovery of Earth’s Earliest Fossils, by J. William Schopf, referenced above, is here: https://regarp.com/2017/05/14/review-of-cradle-of-life-the-discovery-of-earths-e...
Review of: Life in Deep Time: Darwin’s “Missing” Fossil Record, by J. William Schopf https://regarp.com/2019/05/05/review-of-life-in-deep-time-darwins-missing-fossil...… (altro)
by Stan Prager (5-5-19)
As a reader, some of my most serendipitous finds have been plucked off the shelves of used bookshops. Such was the case some years ago with Cradle of Life: The Discovery of Earth’s Earliest Fossils, by J. William Schopf, a fascinating account of how the author in 1965 was the first to discover Precambrian microfossils of prokaryotic life in stromatolitic sediments in Australia’s Apex chert dated to 3.5 billion years ago, the oldest confirmed evidence for life on earth at the time. My 2017 review of Cradle of Life—nearly twenty years after it was first published—sparked an email exchange with Bill Schopf that later led to his sending me a signed edition of his most recent book, Life in Deep Time: Darwin’s “Missing” Fossil Record. He did not ask me to read and review it, but naturally I did.
In this work, Schopf—an unusually modest man of outsize accomplishment—typically credits good fortune rather than his own estimable talents, often emphasizing the centrality of teamwork in the pursuit of sound science, as well as frequently paying tribute to the notion that each discovery and its discoverers are after all “standing on the shoulders of the giants” that preceded them. A young grad student when he first got into the game, at seventy-seven the author now remains the most significant living survivor of those paleobiologists that devoted decades in an effort to identify and substantiate traces of the most ancient forms of life on the planet. He feels the clock ticking, and thus is strongly motivated by a desire to leave a record of the journey that led to such consequential discoveries now that most of his peers have passed on.
The result is Life in Deep Time, a curious book—actually something of a blend of three different kinds of books—that succeeds more often than not in its efforts, even if at times it can be an uphill climb for the general reader. It is first and foremost a memoir that dwells for a surprisingly long time on the author’s youth and upbringing, which can be awkward at times because of his decision to employ a third-person limited literary technique in the narrative, so that it is “Bill wondered about …” rather than “I wondered about …” Early on, the reader might grow a bit impatient as Bill negotiates high school, often under the disapproving glare of his father, an admirable man who nevertheless sets impossibly high standards for his son and is quite difficult to please. Yet, even then Schopf is ever the optimist, always grateful for that which goes his way, and treating that which does not as a valuable learning experience. Rather than being scarred from the travails of enduring a demanding parent, he seems to sit in awe of a father who sets challenges that are always another chalk-mark higher than Bill can grasp. Such circumstances for another might leave that child a substance abuser or a ne’er-do-well, but it simply inspires Bill Schopf to be the best-of-the-best, fully absent an uncontainable ego or an axe to grind.
Beyond memoir, the second focal point of the book recounts Schopf’s scientific achievements, while paying tribute to those he worked with, many of whom are little known or entirely unknown outside of the paleobiology community. Science, the author repeatedly underscores, is a team effort. While the ever-modest Schopf does not dodge the recognition he clearly deserves for his key contributions to the field, he makes certain that credit gets appropriately shared among mentors and colleagues and even assistants.
Schopf’s work has spawned controversy that sometimes spilled over into the public arena. In the first case, there was pushback on his remarkable find of those 3.5-billion-year-old microfossils. Peer-reviewed science upheld his claim, although a prominent rival paleobiologist continued to dispute it. In the second, Schopf was brought in by NASA in 1996 to evaluate the extraordinary if premature announcement that life had been identified in a Martian meteorite, which was trumpeted by scientists, politicians and the media. Schopf was skeptical, and subsequent careful research proved him correct. The author’s well-written examination of these controversies is both coherent and enlightening, although blemished a bit by the continued use of that third-person limited literary technique, which feels especially awkward as he answers his critics through the narrative.
Schopf’s greatest triumph was certainly his discovery of those ancient fossils in Australia’s Apex chert, detailed in Cradle of Life and revisited in Life in Deep Time. Modern science has established that the earth is a little more than 4.5 billion years old, but in the mid-nineteenth century, when Charles Darwin devised his theory of evolution, no one could be sure what the true age of the planet was, although most scientists knew it was far older than the six thousand years that theologians claimed. In his groundbreaking 1859 treatise, On the Origin of Species, Darwin estimated that the erosion of England’s Sussex Weald must have taken some 300 million years, but he was taken to task on this by the famed Lord Kelvin, who publicly scolded that the earth could not possibly be older than 100 million years. Whatever the actual number, Darwin was deeply troubled because the process of natural selection that he envisioned would take much, much longer in order for higher life forms to evolve. In the century that followed Darwin, greater scientific sophistication established the true age of the earth with greater specificity, but it turned out that identifying the planet’s earliest life forms proved quite elusive. This is because traces of these unicellular organisms lacking a membrane-bound nucleus—the prokaryotes that include Archaea and Bacteria—can be maddeningly difficult to identify, and often actually appear to be inorganic remains with strikingly similar characteristics. A famous false positive in this venue set paleobiology back for many decades. As a result, even as late as 1965, Schopf’s find of 3.5-billion-year-old microfossils of prokaryotic life proved controversial, although eventually gained full acceptance by the scientific community.
The science behind all this is remarkably complex, and that is the third focus in Life in Deep Time, a welcome addition for those comfortable with textbooks on paleobiology, but often inaccessible to the general reader. I am trained in history rather than science, so I found some challenging moments in Cradle of Life that had me re-reading a paragraph or two, but much of it was indeed comprehensible to me as a non-scientist, which is not always the case with the final section of Life in Deep Time, which casually includes sentences such as this one:
“By this time, Bill had gained sufficient knowledge of the chemistry of kerogen, the coaly carbonaceous matter of which ancient microscopic fossils are composed, that he imagined that if the dominating polycyclic aromatic ring structures of the fossil kerogen were irradiated with an appropriate wavelength of laser light, they too would fluoresce and produce the images he sought.” [p186]
Material like this is certainly not impenetrable to an educated reader, but long discourses in this vein can lose a wider audience not schooled in paleobiology. Perhaps this content, although critical to scientists reading the book, might have been better placed in the appendix so as not to lose the flow of an otherwise engaging narrative.
While portions of Life in Deep Time may be difficult to navigate for the general reader, I would nevertheless recommend it. Bill Schopf is a remarkable man, a great scientist and a fine writer. The various threads of the tale he relates here add up to a storied saga of the evidenced- based search for the earliest life on the planet, as well as that of the distinguished if often otherwise anonymous men and women who were responsible for marking one of the greatest milestones in recent scientific history. The voice of Bill Schopf is a humble yet commanding one: it deserves to be heard.
[My review of: Cradle of Life: The Discovery of Earth’s Earliest Fossils, by J. William Schopf, referenced above, is here: https://regarp.com/2017/05/14/review-of-cradle-of-life-the-discovery-of-earths-e...
Review of: Life in Deep Time: Darwin’s “Missing” Fossil Record, by J. William Schopf https://regarp.com/2019/05/05/review-of-life-in-deep-time-darwins-missing-fossil...… (altro)
Review of: Cradle of Life: The Discovery of Earth’s Earliest Fossils, by J. William Schopf
by Stan Prager (5-14-17)
Breaking news that recent discoveries may push back traces of the earliest forms of life on earth to a remarkable 3.77 billion years ago brings new relevance to Cradle of Life: The Discovery of Earth’s Earliest Fossils, by J. William Schopf, a dazzling exploration of how science was able to overcome substantial obstacles to look back to the very edges of the dawn of life on our planet. Schopf, professor of earth sciences at UCLA, is a paleobiologist with a long, impressive resume that includes service as NASA's principal investigator of lunar samples during the golden age of manned moon landings. More significantly, it was Schopf himself who in 1965 was the first to discover Precambrian microfossils of prokaryotic life in stromatolitic sediments in Australia's Apex chert dated to 3.5 billion years ago, the oldest confirmed evidence for life at the time. Because new breakthroughs in this field are rare and the science moves forward at a somewhat glacial pace, Cradle of Life–first published in 1999–remains fresh and fascinating.
If references to “prokaryotic life” and “stromatolitic sediments” sound intimidating, the reader should take some comfort in that Schopf’s fast-moving and well-written chronicle is largely accessible to the non-scientist. At the same time, do not overlook the implied caution in “some comfort” and “largely accessible,” but neither should that serve as roadblock to his rewarding if sometimes complicated account. I frequently challenge myself to read above my level, and these forays typically orbit around science and mathematics, where my strengths in historical analysis are of little service to me. I will long remember how humbled I was by The Particle at the End of the Universe, Sean Carroll’s brilliant exposition on the hunt for the Higgs Boson. Such books are a reminder of how smart you aren’t! I came better equipped to Schopf than to Carroll, largely because of my long self-taught study of evolution and paleontology, yet still I found myself tested as I trod through the evidence for ancient microbial life and how it functioned in an ecosystem so distant in time to us that it compels the reader to brave the contours of both science and imagination.
The earth was formed some 4.54 billion years ago, but as recently as the late nineteenth century it was believed to be only 100 million years old. Darwin, who advanced his theory of evolution before the earth’s antiquity was established, was troubled by what he viewed within that framework as the lack of requisite time for the slow process of natural selection to occur. Later, with the age of the planet at least approximated, it yet remained rather fuzzy when organic life first appeared, today believed to be as early as 4.1 billion years ago. Until relatively recent times, it was accepted wisdom that whatever life–simple and microscopic–may have existed before the fossil-rich Cambrian Period (the first geological period of the Paleozoic Era, which began 541 million years ago) left no verifiable remains.
In the opening chapters of Cradle of Life, Schopf neatly summarizes for the non-specialist the fundamentals of earth science, geology, and plate tectonics, as well as the key concepts of evolutionary biology, before moving on to recount the various attempts to locate evidence of Precambrian life. It turns out that such traces are often ambiguous, and vestiges of life in the layered mineral record bear a striking resemblance to similar nonbiologic designs in sedimentary rock. Experts who fell victim to such errors brought disrepute to the field when shown to be mistaken, which engineered a strong resistance to authentic microfossils when these came to light. Fortunately, for all of its wrong turns, science is self-correcting, and the bulk of this fine book relates the discovery of indisputable ancient fossil life and how that has impacted what we know about evolutionary paleobiology.
Schopf, as noted, was at the forefront of this dramatic breakthrough, which was manifested in his discovery of microfossils of cyanobacteria preserved in stromatolites–accretionary layers produced by the activities of mat-building microorganisms–in the sedimentary rock of some of the oldest pristine continental crust still extant on the planet, in northwestern Australia’s Pilbara Craton. Cyanobacteria, formerly and incorrectly tagged “blue-green algae,” are an ancient single-celled organism that, lacking a nucleus, are characterized as prokaryotes. Cyanobacteria still exist, but were of outsize significance to an early earth that was both starved for oxygen and subject to punishing UV radiation unshielded by an ozone layer that was yet to exist. Critical to the evolution of much of life as we know it, it was cyanobacteria’s pioneering strategy of oxygen-producing photosynthesis that literally created the environment suitable for the explosion of the diversity and complexity of organisms that later populated the planet. As cyanobacteria flourished, vast quantities of oxygen were pumped into the atmosphere that not only created conditions salubrious to evolving life but led to the formation of the protective ozone layer essential to the latter’s survival. In the meantime, cyanobacteria demonstrated an astonishing level of adaptability to a whole host of habitats, a testament to how it is that this “living fossil” remains with us today.
While I see no inherent conflict between science and religion, as a self-styled “dogmatic skeptic” the evolution of life strikes me as even more wondrous and miraculous without the presence of a creator god. Schopf underscores that every form of life on earth is linked to one another, that: “Whether large or small, living or fossil, life comes in just two varieties …” the nonnucleated single-celled prokaryotes like cyanobacteria, and the eukaryotes, which “have chromosomes packaged in a saclike nucleus.” Eukaryotes encompass both single-celled creatures as well as all of the more complex multicellular organisms–like azaleas, ants, frogs and humans–that exist on our planet. The author rhetorically chides us for our “big-organism bias” that puts frequent focus upon plants, fungi and animals–the only three branches of life that “include large, many-celled organisms,” as well as microscopic ones. [p237] Cradle of Life reminds us that the most noteworthy creatures can be those that are invisible to the naked eye. Cyanobacteria, measured in micrometers–a millionth of a meter–are not nearly as wide as a human hair. Life’s four most critical biogenic elements are carbon, hydrogen, oxygen and nitrogen (CHON), so the contributions of oxygen producing cyanobacteria–a microbial single-celled prokaryote–to the evolutionary processes unleashed cannot be overstated. Schopf argues that cyanobacterial oxygenic photosynthesis, and the much later innovation of eukaryotic sex that fueled genetic variation, are the two “surpassingly important” components of evolution ever devised. [p249]
While much of Schopf’s delightful book is accessible to the non-specialist, portions nevertheless present some difficulty to those outside of this field. The complexity is, however, much mitigated by photographs, illustrations, timelines and a comprehensive glossary of terms that I found most helpful. Moreover, Schopf’s prose is both articulate and engaging. While I found some of this read challenging, I came away from the work much rewarded for the effort. For those little familiar with the origins of life on earth and the line that can be drawn from that hazy ancient past to my very fingers typing out this review, Cradle of Life comes highly recommended.
Check out the latest review on the book blog “Cradle of Life: The Discovery of Earth’s Earliest Fossils,” by J. William Schopf, http://wp.me/p5Hb6f-dx
https://regarp.com/2017/05/14/review-of-cradle-of-life-the-discovery-of-earths-e...… (altro)
by Stan Prager (5-14-17)
Breaking news that recent discoveries may push back traces of the earliest forms of life on earth to a remarkable 3.77 billion years ago brings new relevance to Cradle of Life: The Discovery of Earth’s Earliest Fossils, by J. William Schopf, a dazzling exploration of how science was able to overcome substantial obstacles to look back to the very edges of the dawn of life on our planet. Schopf, professor of earth sciences at UCLA, is a paleobiologist with a long, impressive resume that includes service as NASA's principal investigator of lunar samples during the golden age of manned moon landings. More significantly, it was Schopf himself who in 1965 was the first to discover Precambrian microfossils of prokaryotic life in stromatolitic sediments in Australia's Apex chert dated to 3.5 billion years ago, the oldest confirmed evidence for life at the time. Because new breakthroughs in this field are rare and the science moves forward at a somewhat glacial pace, Cradle of Life–first published in 1999–remains fresh and fascinating.
If references to “prokaryotic life” and “stromatolitic sediments” sound intimidating, the reader should take some comfort in that Schopf’s fast-moving and well-written chronicle is largely accessible to the non-scientist. At the same time, do not overlook the implied caution in “some comfort” and “largely accessible,” but neither should that serve as roadblock to his rewarding if sometimes complicated account. I frequently challenge myself to read above my level, and these forays typically orbit around science and mathematics, where my strengths in historical analysis are of little service to me. I will long remember how humbled I was by The Particle at the End of the Universe, Sean Carroll’s brilliant exposition on the hunt for the Higgs Boson. Such books are a reminder of how smart you aren’t! I came better equipped to Schopf than to Carroll, largely because of my long self-taught study of evolution and paleontology, yet still I found myself tested as I trod through the evidence for ancient microbial life and how it functioned in an ecosystem so distant in time to us that it compels the reader to brave the contours of both science and imagination.
The earth was formed some 4.54 billion years ago, but as recently as the late nineteenth century it was believed to be only 100 million years old. Darwin, who advanced his theory of evolution before the earth’s antiquity was established, was troubled by what he viewed within that framework as the lack of requisite time for the slow process of natural selection to occur. Later, with the age of the planet at least approximated, it yet remained rather fuzzy when organic life first appeared, today believed to be as early as 4.1 billion years ago. Until relatively recent times, it was accepted wisdom that whatever life–simple and microscopic–may have existed before the fossil-rich Cambrian Period (the first geological period of the Paleozoic Era, which began 541 million years ago) left no verifiable remains.
In the opening chapters of Cradle of Life, Schopf neatly summarizes for the non-specialist the fundamentals of earth science, geology, and plate tectonics, as well as the key concepts of evolutionary biology, before moving on to recount the various attempts to locate evidence of Precambrian life. It turns out that such traces are often ambiguous, and vestiges of life in the layered mineral record bear a striking resemblance to similar nonbiologic designs in sedimentary rock. Experts who fell victim to such errors brought disrepute to the field when shown to be mistaken, which engineered a strong resistance to authentic microfossils when these came to light. Fortunately, for all of its wrong turns, science is self-correcting, and the bulk of this fine book relates the discovery of indisputable ancient fossil life and how that has impacted what we know about evolutionary paleobiology.
Schopf, as noted, was at the forefront of this dramatic breakthrough, which was manifested in his discovery of microfossils of cyanobacteria preserved in stromatolites–accretionary layers produced by the activities of mat-building microorganisms–in the sedimentary rock of some of the oldest pristine continental crust still extant on the planet, in northwestern Australia’s Pilbara Craton. Cyanobacteria, formerly and incorrectly tagged “blue-green algae,” are an ancient single-celled organism that, lacking a nucleus, are characterized as prokaryotes. Cyanobacteria still exist, but were of outsize significance to an early earth that was both starved for oxygen and subject to punishing UV radiation unshielded by an ozone layer that was yet to exist. Critical to the evolution of much of life as we know it, it was cyanobacteria’s pioneering strategy of oxygen-producing photosynthesis that literally created the environment suitable for the explosion of the diversity and complexity of organisms that later populated the planet. As cyanobacteria flourished, vast quantities of oxygen were pumped into the atmosphere that not only created conditions salubrious to evolving life but led to the formation of the protective ozone layer essential to the latter’s survival. In the meantime, cyanobacteria demonstrated an astonishing level of adaptability to a whole host of habitats, a testament to how it is that this “living fossil” remains with us today.
While I see no inherent conflict between science and religion, as a self-styled “dogmatic skeptic” the evolution of life strikes me as even more wondrous and miraculous without the presence of a creator god. Schopf underscores that every form of life on earth is linked to one another, that: “Whether large or small, living or fossil, life comes in just two varieties …” the nonnucleated single-celled prokaryotes like cyanobacteria, and the eukaryotes, which “have chromosomes packaged in a saclike nucleus.” Eukaryotes encompass both single-celled creatures as well as all of the more complex multicellular organisms–like azaleas, ants, frogs and humans–that exist on our planet. The author rhetorically chides us for our “big-organism bias” that puts frequent focus upon plants, fungi and animals–the only three branches of life that “include large, many-celled organisms,” as well as microscopic ones. [p237] Cradle of Life reminds us that the most noteworthy creatures can be those that are invisible to the naked eye. Cyanobacteria, measured in micrometers–a millionth of a meter–are not nearly as wide as a human hair. Life’s four most critical biogenic elements are carbon, hydrogen, oxygen and nitrogen (CHON), so the contributions of oxygen producing cyanobacteria–a microbial single-celled prokaryote–to the evolutionary processes unleashed cannot be overstated. Schopf argues that cyanobacterial oxygenic photosynthesis, and the much later innovation of eukaryotic sex that fueled genetic variation, are the two “surpassingly important” components of evolution ever devised. [p249]
While much of Schopf’s delightful book is accessible to the non-specialist, portions nevertheless present some difficulty to those outside of this field. The complexity is, however, much mitigated by photographs, illustrations, timelines and a comprehensive glossary of terms that I found most helpful. Moreover, Schopf’s prose is both articulate and engaging. While I found some of this read challenging, I came away from the work much rewarded for the effort. For those little familiar with the origins of life on earth and the line that can be drawn from that hazy ancient past to my very fingers typing out this review, Cradle of Life comes highly recommended.
Check out the latest review on the book blog “Cradle of Life: The Discovery of Earth’s Earliest Fossils,” by J. William Schopf, http://wp.me/p5Hb6f-dx
https://regarp.com/2017/05/14/review-of-cradle-of-life-the-discovery-of-earths-e...… (altro)
An in-depth and exhaustive study of the earliest life on earth. It is amazing that life began so soon after the earth cooled, and also amazing how hard it is to tell early life from natural geological processes (think Martian Meteorite).
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Well illustrated; lots of references to each chapter (again now outdated). Worth it but with the caveat that you need to follow up with more recent works.… (altro)