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So here's a list of some critical questions and answers that might provide us additional insight into the fate of higher lifeforms on other worlds-- based upon our own experiences:
Q: How long have complex lifeforms (which would be vulnerable to these sorts of things) been present on Earth?
A: If we don't count things like algae, maybe around 600 million years. Present evidence indicates around 570 million years-- future finds may extend the number deeper into time.
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THE SHORTER, THE STRANGER From Science Frontiers Digest of Scientific Anomalies #90, NOV-DEC 1993 by William R. Corliss, citing Samuel A. Bowring,, et al; "Calibrating Rates of Early Cambrian Evolution," Science, 261:1293, 1993. Richard A. Kerr; "Evolution's Big Bang Gets Even More Explosive," Science, 261:1274, 1993. R. Monastersky; "Siberian Rocks Clock Biological Big Bang," Science News, 144:142, 1993. Carol Kaesuk Yoon; "Biology's 'Big Bang' Took a Mere Blink of the Eye," New York Times, September 7, 1993. Cr. P. Gunkel
Complex lifeforms appear to require around 3 billion years to develop from simpler life (judging from the Earth's case).
-- Andrew Watson: Forget about aliens: we're all alone in the universe [from a lecture given to the Geological Society at the University of East Anglia, London]; Independent Digital (UK) Ltd; 28 March 2002
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Q: What's been the average frequency of gamma ray bursters in our galaxy over the past 600 million years or so? What about the frequency of other cosmic radiation events which might have affected climate and/or life on Earth over this time?
A: Over the last 600 million years the most suspect periods for gamma burster episodes appear to be the mass extinctions of the Ordovician (439,000,000 BC), and Permian-Triassic (360,000,000 BC- 250,000,000 BC)-- though there's also evidence of a major asteroid or comet strike relating to the Permian-Triassic too. The cosmic impact may have merely been coincidental, mattering little in the wake of a gamma burster, or complemented the burster's effect, thereby adding to the death toll, or extended the period of extinctions for much longer than they might have otherwise lasted. Or, the burster itself could have played second fiddle to the impact, in a similar fashion.
It appears the bursters lasted long enough in both instances to fry at least 60-75% of the Earth's surface life before they faded.
There's the possibility that more than one burster occured during the Permian-Triassic event-- this could help account for the very lengthy period of die offs found by researchers.
If gamma bursters were involved in both these events then the bursts were separated by somewhere between 79 million and 189 million years. And the latest one may have occured sometime between 360 million and 250 million years ago-- which appears to make us overdue for another anytime now (if the frequency holds). YIKES! We're overdue to become just another statistic, folks.
But gamma bursters aren't the only showers of extra radiation from space periodically suffered by Earth. Much less dangerous radiation showers also occur-- sometimes leaving climate changes and less substantial extinction events in their wake. Some of the approximate dates for such events include 5,000,000 BC, 1,006 AD, 1,054 AD, 1,181 AD, 1,320 AD, 1,572 AD, and 1,604 AD. Note that in recent times the average time between such radiation showers has been around 120 years. So we're perhaps overdue for another by some 276 years.
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-- "Nearby Supernova May Have Caused Mini-Extinction, Scientists Say", ScienceDaily Magazine, http://www.sciencedaily.com//releases/1999/08/990803073658.htm, 8/3/99, Source: SciNews-MedNews, University of Illinois Urbana-Champaign
31-Jul-99, Contact: James E. Kloeppel, Physical Sciences Editor (217) 244-1073; kloeppel@uiuc.edu
-- "Can Supernovas Scar Earth?" By Mark Sincell, Discovery News Brief, Discovery Online, http://www.discovery.com/, found on or about 9-23-99
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Q: What's been the average frequency of large comet and/or asteroid impacts on Earth over the past 600 million years or so?
A: This is a toughie, since our information on these points is very spotty, and the frequency has hopefully been lowering over time, similar to how gamma burster frequency is said to have done. Events like Tunguska in 1,908 AD also seem to show that some comet impacts may not leave craters at all, but still possibly affect climate over large regions, or even globally. Some scientists believe some global climate changes in the past came from Earth merely passing through the dust wake of a comet tail.
Fortunately, we do have some noteworthy impacts and related numbers to draw upon. 590 million BC, 370 million BC, 364 million BC, 150 million BC, 65 million BC, 35 million BC, 35.5 million BC, and 2.3 million BC all seem to have marked such impact or related events. Note that the average time between events appears to be some 84 million years-- which means we might not see another until around 82 million AD (if the average holds).
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-- Secret strike By Tim Thwaites; New Scientist, 7 August 1999
-- Tiny Teeth Shed Light on Ancient Comets; 3/20/98; News Release; U.S. Department of the Interior; U.S. Geological Survey, Central Region Outreach Office, P.O. Box 25046, MS 150, Denver, CO 80225-0046. Contact Heidi Koehler Phone 303-236-5900 ext. 302 Fax 303-236-5882
-- Killer Crater Found By Larry O'Hanlon,
Discovery.com News, April 19, 2000
-- Europe's biggest smash hit By Dr David Whitehouse; Sci/Tech; BBC News Online, February 15, 1999, http://www.bbc.co.uk/
-- 2150 biodiversity
-- "Did the Dark Ages begin with a bang?" by Robert Matthews
Connected, Electronic Telegraph, http://www.telegraph.co.uk,
29 July 1999, Telegraph Group Limited
-- "Dino Deaths Revisited
Meteor May Not Have
Destroyed Them, After All" By Kenneth Chang
ABCNEWS.com, Sept. 26, 1999, http://www.abcnews.go.com, ABC News Internet Ventures
-- GLOBAL FIRE AT THE K-T BOUNDARY from Science Frontiers Digest of Scientific Anomalies #60, NOV-DEC 1988, by William R. Corliss, citing Wendy S. Wolbach, et al; "Global Fire at the Cretaceous-Tertiary Boundary," Nature, 334:665, 1988
-- THE CRETACEOUS INCINERATION from Science Frontiers Digest of Scientific Anomalies #43, JAN-FEB 1986 by William R. Corliss, citing Wendy S. Wolbach, et al; "Cretaceous Extinctions: Evidence for Wildfires and Search for Meteoric Material," Science, 230:167, 1985
-- Were the last dinosaurs roasted alive? by Michael Day
New Scientist issue: 20th November 99
Source: Geo-Marine Letters (vol 18, p 285), http://www.newscientist.com and EurekAlert!
-- Tiny Teeth Shed Light on Ancient Comets; 3/20/98; News Release; U.S. Department of the Interior; U.S. Geological Survey, Central Region Outreach Office, P.O. Box 25046, MS 150, Denver, CO 80225-0046. Contact Heidi Koehler Phone 303-236-5900 ext. 302 Fax 303-236-5882
-- GIANT IMPACT-WAVE DEPOSIT ALONG U.S. EAST COAST From Science Frontiers Digest of Scientific Anomalies #87, MAY-JUN 1993 by William R. Corliss, citing C. Wylie Poag, et al; "Deep Sea Drilling Project Site 612 Bolide Event: New Evidence of a Late Eocene Impact-Wave Deposit and a Possible Impact Site, U.S. East Coast," Geology, 20:771, 1992
-- earth : When it's cool to be cool by PHILIP BALL, 4 August 2000, Nature, Macmillan Publishers Ltd.
-- "Researchers Amazed to Find Tools More Than 2 Million Years Old" Compiled by Times medical writer Thomas H. Maugh II , May 6, 1999, Los Angeles Times, Science in Brief
-- DID AN ASTEROID IMPACT TRIGGER THE ICE AGES? From Science Frontiers Digest of Scientific Anomalies #59, SEP-OCT 1988 by William R. Corliss, citing Frant T. Kyte, et al; "New Evidence on the Size and Possible Effects of a Late Pliocene Oceanic Asteroid Impact," Science, 241:63, 1988
-- TWO CATASTROPHE SCENARIOS From Science Frontiers Digest of Scientific Anomalies #117, MAY-JUN 1998 by William R. Corliss, citing Jeff Hecht; "A Bigger Splash," New Scientist, p. 11, November 1, 1997, and Anonymous; "The Splash Felt 'round the World," Earth, 7:12, April 1998
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Q: What's been the average frequency of catastrophic geological upheaval on Earth over the past 600 million years or so?
A: 534 million BC, 200 million BC, 84 million+ BC, 65 million BC, 55.5 million BC, and 69,000 BC represent notable instances of massive geological upheaval which possibly had big effects on climate. The average frequency of these events seems to have been once every 107 million years. If the average also gives us a rough estimate of when to expect the next one, we may have around 107 million years to wait.
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EARTH'S SHIFTING CRUST From Science Frontiers Digest of Scientific Anomalies #113, SEP-OCT 1997 by William R. Corliss, citing Joseph L. Kirschvink, et al; "Evidence for a Large-Scale Reorganization of Early Cambrian Continental Masses by Inertial Interchange True Polar Wander," Science, 277:541, 1997, Kathy Sawyer; "Global Shift May Have Sped Evolution," Washington Post, July 25, 1997, and Kurt P. Wise, "The Archaean Explosion," CEN Technical Journal, 10:315, 1996
-- TWO REALLY DEEP OCEANS from Science Frontiers Digest of Scientific Anomalies #96, NOV-DEC 1994 by William R. Corliss, citing Carl Zimmer; "The Ocean Within," Discover, 15:20, October 1994, and Martin Redfern; "Lost Ocean Found Deep in the Earth," New Scientist, p. 16, September 3, 1994
-- "Eruptions Cleared Path for Dinosaurs" By R. Monastersky
Science News Online, Volume 155, Number 17 (April 24, 1999), ScienceService
-- Lecture 14 - The Appalachian Mountains, last reviewed by respective author(s) on 2/18/00, found by J.R. Mooneyham on or about 7-8-2000
-- The creatures time forgot by Lynn Dicks, From New Scientist, 23 October 1999
-- Study: Earth Once Wobbled, Jan. 21, 2000, Associated Press/Discovery Online News Brief/Discovery Communications Inc./http://www.discovery.com/
-- Fast tilt, From New Scientist magazine, 29 January 2000
-- "The world's oceans seem to be draining away" by Peter Hadfield, Tokyo, New Scientist issue 11th September 99, http://www.newscientist.com, 8 SEPTEMBER 1999, EurekAlert!
-- 2150 biodiversity
-- "Did the Dark Ages begin with a bang?" by Robert Matthews
Connected, Electronic Telegraph, http://www.telegraph.co.uk,
29 July 1999, Telegraph Group Limited
-- "Dino Deaths Revisited
Meteor May Not Have
Destroyed Them, After All" By Kenneth Chang
ABCNEWS.com, Sept. 26, 1999, http://www.abcnews.go.com, ABC News Internet Ventures
-- GLOBAL FIRE AT THE K-T BOUNDARY from Science Frontiers Digest of Scientific Anomalies #60, NOV-DEC 1988, by William R. Corliss, citing Wendy S. Wolbach, et al; "Global Fire at the Cretaceous-Tertiary Boundary," Nature, 334:665, 1988
-- THE CRETACEOUS INCINERATION from Science Frontiers Digest of Scientific Anomalies #43, JAN-FEB 1986 by William R. Corliss, citing Wendy S. Wolbach, et al; "Cretaceous Extinctions: Evidence for Wildfires and Search for Meteoric Material," Science, 230:167, 1985
-- Were the last dinosaurs roasted alive? by Michael Day
New Scientist issue: 20th November 99
Source: Geo-Marine Letters (vol 18, p 285), http://www.newscientist.com and EurekAlert!
-- Evidence for historic global warming published in Science, EurekAlert!, University of California, Santa Barbara, 18 NOVEMBER 1999, Contact: Gail Brown, gbrown@instadv.ucsb.edu,
805-893-7220
-- Geologists pinpoint source of major global warming event more than 55 million years ago, National Science Foundation /EurekAlert!, 19 NOVEMBER 1999, Contact: Cheryl Dybas
cdybas@nsf.gov
703-306-1070
-- Ocean Burp Caused Global Warming, Associated Press/Discovery Online News Brief, http://www.discovery.com/, found on or about 11-19-99
-- Paleoanthropology (revised 16 December 1999) by Francis F. Steen, Department of English, University of California at Santa Barbara, http://cogweb.english.ucsb.edu/EP/Paleoanthropology.html
-- "Ancient 'volcanic winter' tied to rapid genetic divergence in humans", News From the University of Illinois at Urbana-Champaign, September 1998, News Bureau
University of Illinois at Urbana-Champaign
807 S. Wright St., Suite 520 East
Champaign, IL 61820-6219, found on or about 9-10-98
-- "History Of Humans And Great Apes Strikingly Different"
University Science, 27-Apr-1999, UniSci Science and Research News, http://unisci.com
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Q: What's been the average frequency of notable extinction events on Earth over the past 600 million years or so?
A: A list of such extinction events would include the following dates: 439 million BC, 367 million BC- 245 million BC, 220 million BC- 208 million BC, 65 million BC, 13 million BC, 5 million BC, and 3 million BC- 2 million BC. The average time between events seems to be some 73 million years (For my calculations I used a number near the median of the values which represented ranges rather than specific dates). Thus, in terms of naturally inspired notable extinction events, we might be about 71 million years away.
Unfortunately, humanity has over the past 50,000 years or so initiated its own unnatural global extinction event-- which shows signs of possibly expanding to include us as well, within the next 200 years or so. But that's a topic to be dealt with elsewhere.
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-- Killer Crater Found By Larry O'Hanlon,
Discovery.com News, April 19, 2000
-- 2150 biodiversity and WRI Article: "A History of Extinction"
-- Meltdown By Diana Steele, From New Scientist, 7 August 1999
-- NOW, IT'S COMET SHOWERS THAT DID IT From Science Frontiers Digest of Scientific Anomalies #54, NOV-DEC 1987 by William R. Corliss, citing Piet Hut, et al; "Comet Showers as a Cause of Mass Extinctions," Nature, 329:118, 1987
-- A PERMIAN POLAR FOREST From Science Frontiers Digest of Scientific Anomalies #84, NOV-DEC 1992 by William R. Corliss, citing Edith L. Taylor, et al; "The Present Is Not the Key to the Past: A Polar Forest from the Permian of Antarctica," Science, 257:1675, 1992
-- Scientific American: IN BRIEF: Fast Extinction (appears from the URL to be the August 1998 issue)
-- New evidence indicates huge vegetation loss accompanied mass extinction, 7 SEPTEMBER 2000, EurekAlert!, Contact: Vince Stricherz, vinces@u.washington.edu,
206-543-2580, University of Washington
-- "Did the Dark Ages begin with a bang?" by Robert Matthews
Connected, Electronic Telegraph, http://www.telegraph.co.uk,
29 July 1999, Telegraph Group Limited
-- "Dino Deaths Revisited
Meteor May Not Have
Destroyed Them, After All" By Kenneth Chang
ABCNEWS.com, Sept. 26, 1999, http://www.abcnews.go.com, ABC News Internet Ventures
-- GLOBAL FIRE AT THE K-T BOUNDARY from Science Frontiers Digest of Scientific Anomalies #60, NOV-DEC 1988, by William R. Corliss, citing Wendy S. Wolbach, et al; "Global Fire at the Cretaceous-Tertiary Boundary," Nature, 334:665, 1988
-- THE CRETACEOUS INCINERATION from Science Frontiers Digest of Scientific Anomalies #43, JAN-FEB 1986 by William R. Corliss, citing Wendy S. Wolbach, et al; "Cretaceous Extinctions: Evidence for Wildfires and Search for Meteoric Material," Science, 230:167, 1985
-- Were the last dinosaurs roasted alive? by Michael Day
New Scientist issue: 20th November 99
Source: Geo-Marine Letters (vol 18, p 285), http://www.newscientist.com and EurekAlert!
-- A UNIFIED THEORY OF GEOPHYSICS From Science Frontiers Digest of Scientific Anomalies #98, MAR-APR 1995 by William R. Corliss, citing Richard Monastersky; "Shots from Outer Space," Science News, 147:58, 1995
-- Evidence for historic global warming published in Science, EurekAlert!, University of California, Santa Barbara, 18 NOVEMBER 1999, Contact: Gail Brown, gbrown@instadv.ucsb.edu,
805-893-7220
-- Geologists pinpoint source of major global warming event more than 55 million years ago, National Science Foundation /EurekAlert!, 19 NOVEMBER 1999, Contact: Cheryl Dybas
cdybas@nsf.gov
703-306-1070
-- Ocean Burp Caused Global Warming, Associated Press/Discovery Online News Brief, http://www.discovery.com/, found on or about 11-19-99
-- "Seafood Was Brain Food, Says Researcher", CONTACT:
Bruce Rolston, U of T Public Affairs, (416) 978-6974, bruce.rolston@utoronto.ca, ScienceDaily Magazine, http://www.sciencedaily.com//releases/1999/08/990827152557.htm, 8/30/99, Source: University Of Toronto
-- "Nearby Supernova May Have Caused Mini-Extinction, Scientists Say", ScienceDaily Magazine, http://www.sciencedaily.com//releases/1999/08/990803073658.htm, 8/3/99, Source: SciNews-MedNews, University of Illinois Urbana-Champaign
31-Jul-99, Contact: James E. Kloeppel, Physical Sciences Editor (217) 244-1073; kloeppel@uiuc.edu
-- "NOT WITH A BANG BUT A WHIMPER" From Science Frontiers Digest of Scientific Anomalies #107, SEP-OCT 1996 by William R. Corliss, citing Ray Jayawardhana; "Earth Menaced by Superbubble," New Scientist, p. 15, June 22, 1996
-- "The First Human?" By Robert Locke, Discovering Archaeology, July/August 1999, http://www.discoveringarchaeology.com/
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Q: What's been the average frequency of major tsunamis or global flooding events on Earth over the past 600 million years or so, which were possibly NOT directly related to any of the above events?
A: Again, our records here are spotty-- but we do know about such events around 998,000 BC, 98,000 BC, and 15,000 BC to 3,000 BC.
Here our sample is terribly small-- so I'm unsure what good an average from the numbers would be. Plus, the 15,000 BC- 3,000 BC event represents the flooding due to the end of the last glaciation of the current Ice Age-- a spike which likely belongs in its own wholly owned category along with other Ice Age related sea changes over the past 2 million years and during other icey epochs. But I don't have the info for that.
So how about this? We'll assume that all land-based civilizations of a given one million year star farer generation has suffered or will suffer at minimum three catastrophic tsunamis and/or global sea level changes during their span.
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-- Landslide By Jonathan Knight, From New Scientist, 7 August 1999
-- "Was The Lack Of Language The Force Of Driving Stone Age Art?", 12-9-98, New Scientist
-- TWO TSUMANI TALES From Science Frontiers Digest of Scientific Anomalies #85, JAN-FEB 1993 by William R. Corliss, citing Garry Davidson; "A Tsunamis Tale from Sydney," New Scientist, p. 17, October 17, 1992, and Jan Smit, et al; "Tektite-Bearing, Deep-Water Clastic Unit at the Cretaceous-Tertiary Boundary in Northeastern Mexico," Geology, 20:99, 1992
-- EVIDENCE FOR A GIANT PLEISTOCENE SEA WAVE From Science Frontiers Digest of Scientific Anomalies #37, JAN-FEB 1985 by William R. Corliss, citing James G. Moore, and George W. Moore; "Deposit from a Giant Wave on the Island of Lanai, Hawaii, Science, 226:1312, 1984
-- "ANCIENT SEAFARERS"BY PETER BELLWOOD, SPECIAL REPORT, Volume 50 Number 2 March/April 1997, the Archaeological Institute of America, http://www.archaeology.org/9703/etc/specialreport.html
-- "Evidence For Earliest Maritime-Based Societies In The Americas Reported"
In Science Magazine, 17 SEPTEMBER 1998, American Association for the Advancement of Science
-- Rise in Sea Levels To Double, Discovery News Brief , http://www.discovery.com/, found on or about 9-15-99
-- page 446, "Traces of our Forebears", National Geographic, October 1988
-- METHANE HYDRATE: PAST FRIEND OR FUTURE FOE? From Science Frontiers Digest of Scientific Anomalies #77, SEP-OCT 1991 by William R. Corliss, citing "Did Methane Curb Ice Ages," New Scientist, p. 24, May 25, 1991, and Tim Appenzeller; "Fire and Ice under the Deep-Sea Floor," Science, 252:1790, 1991
-- GAS HYDRATES AND THE BERMUDA TRIANGLE From Science Frontiers Digest of Scientific Anomalies #25, JAN-FEB 1983 by William R. Corliss, citing Richard D. McIver; "Role of Naturally Occurring Gas Hydrates in Sediment Transport," American Association of Petroleum Geologists, Bulletin, 66:789, 1982
-- "Antarctic Ice Core Hints Abrupt Warming Some 12,500 Years Ago May Have
Been Global", 1 OCTOBER 1998,
University of Colorado at Boulder
-- "Surprise: Geologists Find Glaciers Can Suppress Volcanic Eruptions", 12-8-98, University of North Carolina at Chapel Hill
-- Damburst By Daniel Pendick, From New Scientist, 7 August 1999 (issue 2198)
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Q: What's been the average frequency of worldwide ecological catastrophe on Earth over the past 600 million years or so, for which a specific cause has yet to be determined?
A: Everything I have in this category is extremely recent. Tree growth rings and rare historical accounts of the times point to worldwide ecological catastrophe occuring around 2,354 BC, 1,628 BC, 1,159 BC, 208 BC, and 536 AD- 541 AD.
The causes may have been asteroid/comet impacts (or near-misses dusting the atmosphere), large volcanic eruptions, or perhaps even the passing of the Earth through a great cloud of cosmic dust in space.
The average time between these events has been approximately 723 years. This implies that we may be overdue for another by around 739 years (YIKES!).
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-- "Chaos from Above-- Did Asteroids and Comets Turn the Tides of Civilization?" by MIKE BAILLIE, Discovering Archaeology, http://www.discoveringarchaeology.com
-- "Did the Dark Ages begin with a bang?" by Robert Matthews
Connected, Electronic Telegraph, http://www.telegraph.co.uk,
29 July 1999, Telegraph Group Limited
-- THE 536 AD DUST-VEIL EVENT From Science Frontiers Digest of Scientific Anomalies #96, NOV-DEC 1994 by William R. Corliss, citing "Raining Death and Dark Ages," London Times, July 27, 1994. Cr. A. Rothovius and M.G.L. Baillie; "Dendrochronology Raises Questions about the Nature of the AD 536 Dust-Veil Event," The Holocene, 4:212, 1994. Cr. L. Ellenberger
-- MYSTERY CLOUD OF AD 536 From Science Frontiers Digest of Scientific Anomalies #33, MAY-JUN 1984 by William R. Corliss citing R.B. Stothers; "Mystery Cloud of AD 536," Nature, 307:344, 1984
-- COLLISION/ERUPTION/EXTINCTION/ MAGNETIC REVERSAL From Science Frontiers Digest of Scientific Anomalies #60, NOV-DEC 1988 by William R. Corliss, citing "Regular Reversals in Earth's Magnetic Field A Fluke?" New Scientist, p. 32, August 25, 1988
-- GEOMAGNETIC REVERSALS FROM IMPACTS ON THE EARTH From Science Frontiers Digest of Scientific Anomalies #49, JAN-FEB 1987 by William R. Corliss, citing Richard A. Muller, and Donald E. Morris; "Geomagnetic Reversals from Impacts on the Earth," Geophysical Re search Letters, 13:1177, 1986
-- METEOR-IMPACT WINTERS, MAGNETIC FIELD REVERSALS AND TEKTITES From Science Frontiers Digest of Scientific Anomalies #53, SEP-OCT 1987 by William R. Corliss, citing Bertram Schwartzschild; "Do Asteroid Impacts Trigger Geomagnetic Reversals?" Physics Today, 40:17, February 1987
-- GEOCORROSION? From Science Frontiers Digest of Scientific Anomalies #48, NOV-DEC 1986 by William R. Corliss, citing I. Peterson; "Tracing Corrosion's Magnetic Field," Science News, 130:132, 1986
-- Computer simulations reveal the workings of the dynamo behind earth's magnetic field, EurekAlert! Contact: Tim Stephens
stephens@cats.ucsc.edu
831-459-2495
University of California, Santa Cruz, 20 FEBRUARY 2000
-- "ALMOST INCONCEIVABLE" CHANGES IN THE GEOMAGNETIC FIELD From Science Frontiers Digest of Scientific Anomalies #101 Sep-Oct 1995 by William R. Corliss, citing R.S. Coe, et al; "New Evidence for Extraordinarily Rapid Change of the Geomagnetic Field during a Reversal," Nature, 374:687, 1995. Ronald T. Merrill; "Principle of Least Astonishment," Nature, 374:674, 1995
-- WANTED: DISASTERS WITH A 26-MILLION-YEAR PERIOD From Science Frontiers Digest of Scientific Anomalies #31, JAN-FEB 1984 by William R. Corliss, citing C. Simon; "Pattern in Mass Extinctions," Science News, 124:212, 1983
-- WRI Article: "A History of Extinction"
-- Modeling Earth: Why the force is with us By Robert Roy Britt, explorezone.com NEWS, http://www.flycast.com, 10.27.99
-- WHENCE THE EARTH'S PULSE? From Science Frontiers Digest of Scientific Anomalies #87, MAY-JUN 1993 by William R. Corliss, citing Michael R. Rampino, and Ken Caldeira; "Major Episodes of Geologic Change:
Correlations, Time Structure and Possible Causes," Earth and Planetary Science
Letters, 114:215, 1993
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Q: So how fast could life recover evolution-wise from such calamities?
A: It appears Earth on average requires about 10 million years to recover from a fairly wide scale of global extinction events, ranging from massive species extinctions to considerably smaller events. The inability of evolution to recover more quickly than this seems to be due to entire ecosystems collapsing when critical species within them die. Therefore, a bootstrapping process involving both replacement species and replacement ecosystems to support them, must take place.
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-- Inherent speed limit governs how quickly life bounces back after extinction, UC Berkeley research shows; 2-Jan-2002
Contact: Robert Sanders
rls@pa.urel.berkeley.edu
510-643-6998
University of California - Berkeley
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