October 30: Panspermia is reconsidered on Space.com, after the revival of 250-million-year-old halophiles and the news that germs could have survived a trip from Mars. Chandra Wickramasinghe, geophysicist Jay Melosh, British meteoritic researcher Matthew Genge, and writer Paul Davies were interviewed for the stories.
The New Case for Panspermia, by Robert Roy Britt, Space.com, 30 October 2000.
Panspermia Q and A [with] Chandra Wickramasinghe, by Robert Roy Britt, Space.com, 27 October 2000.
...Panspermia Q and A With Jay Melosh, by Robert Roy Britt, Space.com, 27 October 2000.
Life On Earth Could Have Come From A Mars Rock, by Robert Roy Britt, Space.com, 26 October 2000.
Introduction... is a related CA webpage.
October 27:
NASA announces new Mars program. Instead of two missions per launch window there will be one. The six missions planned for this decade include mapping, surface rovers, and collaboration with Italian or French partners. Sample return is postponed from 2005 until at least 2011. "We will seek before we sample," said Scott Hubbard, NASA's Mars Program director.
NASA Outlines Mars Exploration Program for Next Two decades, NASA, 26 October 2000.
NASA Unveils Its 21st Century Mars Campaigns, Space.com, 26 October 2000.
Mars Reality Check: The High Cost, and Hopes, of Exploration, Space.com, 25 October 2000.
Life on Mars! is the related CA webpage.
October 27:
Mars meteorite could have brought life. A new analysis shows that the interior of ALH84001 was never too hot for cells to survive. A preliminary report of this result was given at NASA's Astrobiology Conference in April.
Benjamin P. Weiss et al., "A Low Temperature Transfer of ALH84001 from Mars to Earth" [abstract], p 791-795 v 290 Science, 27 October 2000.
Benjamin P. Weiss and Joseph L. Kirschvink, "Life From Space?" p 8-11, The Planetary Report, November/December 2000.
Reuters, "Mars Rock Could Have Carried Life, Study Shows," [text], The New York Times, 27 October 2000.
Meteorites may have transferred life between planets in the solar system, McGill University, 26 October 2000.
New look at Martian meteorite breathes new life into 'panspermia' theory, exn.ca, 27 October 2000.
Astrobiology Conference, 6 April 2000, is the CA What'sNEW item mentioning the preliminary report.
Microfossil from the moon |
October 27: Microorganisms from the Moon — Russian biologists examining published microphotos of lunar regolith examples have noticed that some of the particles are fossilized microorganisms. Stanislav Zhmur and Lyudmila Gerasimenko made the discovery when they took a careful new look at moon material collected in the 1970s by missions of the Soviet Union's unmanned Luna program. Their analysis was first published in December 1999, in the proceedings of an astrobiology conference.
At the same conference, these biologists reported fossilized microorganisms in carbonaceous meteorites, and on 27 January, we publicized that finding. Today, no one doubts that the meteoritic fossils are biological. But it turns out that meteorites can easily become contaminated after contact with the ground, so mainstream science now suspects that all meteoritic fossils are contaminants. The fossilized microorganisms from the moon, however, were delivered to Earth in sealed containers that were opened only in laboratories. They can hardly be the remains of recent, earthly contaminants.
One circular fossil collected by Luna 16 (shown) bears an unmistakable resemblance to modern spiral filamentous microorganisms like Phormidium frigidum. Other particles returned by Luna 20 plainly resemble fossils of modern coccoidal species like Siderococcus or Sulfolobus. These fossils are solid evidence for ancient life beyond planet Earth.
Stanislav I. Zhmur and Lyudmila M. Gerasimenko. "Biomorphic forms in carbonaceous meteorite Alliende and possible ecological system - producer of organic matter hondrites" in Instruments, Methods and Missions for Astrobiology II, Richard B. Hoover, Editor, Proceedings of SPIE Vol. 3755 p. 48-58 (1999).
Microorganisms from the Moon has the full CA story with additional photos.
9 July 2004: This may be an impact crater after all! See linked images.
October 25:
Red and grey Kuiper-belt objects have different orbits. Of the thirteen 'classical' KBOs roughly 45 AU from the sun, the ten very red ones are in orbits close to the the ecliptic plane, while all three grey ones are in tilted orbits. The discovery was made by same astronomers who reported the sharp red - grey color distinction of KBOs in March 1998. At that time, Wickramasinghe and Hoyle speculated that red objects might host microbial activity while grey ones didn't. Because orbits can influence climates, now we are even more intrigued.
S.C. Tegler and W. Romanishin, "Extremely red Kuiper-belt objects in near-circular orbits beyond 40 AU" [text], p 979 - 981, v 407, Nature, 26 October 2000.
Brian G. Marsden, "Astronomy: The red ragged edge" [text], p 952 - 955, v 407, Nature, 26 October 2000.
Rash of Red Asteroids Puzzles Researchers, by Robert Roy Britt, Space.com, 25 October 2000.
...Two distinct classes of Kuiper-belt objects..., 21 March 1998, is the related CA What'sNEW item.
The Astonishing Redness of Kuiper-belt Objects is Wickramasinghe and Hoyle's story.
October 23:
An astrobiologist's recommendations for Mars — Chris McKay of NASA's Ames Research Center thinks we should bio-engineer Mars with life from Earth, unless Mars has life already. In that case, we should enable that life to flourish there separately. McKay's discussion of the possible similarity of newfound life forms to ours — only biochemically, or also genetically — is especially illuminating. Cosmic Ancestry expects any life on Mars to resemble Earth's in both ways.
Balancing The Rights Of Indigenous Martian Life Over Human Exploration, by Christopher P. McKay, SpaceDaily.com, 23 October 2000.
Life on Mars! is a related CA webpage.
Detail of salt crystal showing the brine inclusion that contained the bacterium (below "i"). The inclusion is approximately 3x3x1 mm. A drill hole is visible above the vertical arrow. |
October 19: 250 Million-year-old bacteria have been revived. Previously unknown spore-forming bacteria were isolated from a brine inclusion within a salt crystal collected in October 1998, at a depth of 569 meters in a mineshaft in Carlsbad, New Mexico. The analysis by two biologists and a geologist was done so carefully at every stage that contamination is extremely unlikely.
Even more ancient claims exist, but the care taken in this investigation extends the proven survival time of bacterial spores, established by Cano and Borucki in 1995, from tens to hundreds of millions of years. In commentary on the report R. John Parkes wonders, "If bacteria can survive for this length of time, why should they die at all?" And The Washington Post says, "If the findings are upheld, [they] will strengthen arguments that seeds of life might have spread to Earth (or vice versa)...".
The ancient age of the salt crystals from the Permian Salado Formation is confirmed by fossils in overlying strata and by the radiometric ages of minerals above and around the extraction. Crystal features and original structures in the Salado beds indicate that the salt particles were not disturbed after they formed. Most, but not all scientists, find the report convincing. (For a doubter, see Nicholas Wade.)
Russell H. Vreeland, William D. Rosenzweig and Dennis W. Powers, "Isolation of a 250 million-year-old halotolerant bacterium from a primary salt crystal" [abstract], p 897-900, v 407, Nature, 19 October 2000.
R. John Parkes, "Microbiology: A case of bacterial immortality?" p 844-845, v 407, Nature, 19 October 2000.
Kathy Sawyer, "Oldest Living Bacteria Are Revived" [text] p A02, The Washington Post, 19 October 2000.
Nicholas Wade, "Ancient Bacterium Is Reported Found" [text], The New York Times, 19 October 2000.
Hardcore hibernation, by David Adam, Nature science update, 19 October 2000.
Scientists revive 250 million-year-old bacteria, by Matthew Fordahl, AP, Nandotimes.com, 18 October 2000.
Alive...after 250 million years, BBCNews, 18 October 2000.
Bacteria... is a related CA webpage referencing Cano and Borucki.
Can The Theory Be Tested? is a related CA webpage.
Cindy L. Satterfield et al, "New evidence for 250 Ma age of halotolerant bacterium from a Permian salt crystal" [abstract], doi:10.1130/G21106.1, p 265-268 v 33 n 4, Geology, Apr 2005: "These results support the 250 Ma age of the fluid inclusions, and by inference, the long-term survivability of microorganisms such as Virgibacillus sp."
October 15:
Entire genetic regions appear to have been transferred between species. Many have been transferred between domains, from bacteria to archaea. This conclusion comes from the international team that recently sequenced the genome of the archaebacterium Thermoplasma acidophilum. The conserved clusters, averaging about three genes in size, tend to be found near "hot spots" on the chromosome. In commentary to the article in Nature, Don Cowan calls the high level of transferred genes "the most startling observation" to come from the new sequence.
Andreas Ruepp et al., "The genome sequence of the thermoacidophilic scavenger Thermoplasma acidophilum" [abstract], p 508-513, v 407, Nature, 28 September 2000.
Don Cowan, "Use your neighbour's genes" [text], p 466-467, v 407, Nature, 28 September 2000.
Viruses... is a related CA webpage. [Next-What'sNEW about HGT-Prev]
October 13:
More about Tagish Lake meteorite. A story in today's Science gives preatmospheric orbit, mass, and initial compositional characterization of the meteorite that fell in Canada's Yukon territory on 18 January. Probably from the Apollo asteroids, it struck the atmosphere with a mass estimated at 200,000 kilograms. Its primitive material adds much to our knowledge of the early solar system. We await a search for fossilized germs in it.
Peter G. Brown et al., "The Fall, Recovery, Orbit, and Composition of the Tagish Lake Meteorite: A New Type of Carbonaceous Chondrite" [abstract], p 320-325, v 290, Science, 13 October 2000.
Jeffrey N. Grossman, "A Meteorite Falls on Ice" [summary], p 283-285, v 290, Science, 13 October 2000.
John Noble Wilford, "Clues to Life May Come From Meteorite" [text], The New York Times, 13 October 2000.
Cosmic Time Capsule: Frozen Yukon Meteorite Found, by Robert Roy Britt, Space.com, 12 October 2000.
Is Meteorite Most Primitive Sample Of Solar System?, by Steven N. Koppes, Unisci.com, 13 October 2000.
Meteorites may be most primitive solar system material ever studied, University of Calgary, 12 October 2000.
Comets... is a related CA webpage.
October 6:
Isolated giant planets forming. Researchers from the Instituto de Astrofisica de Canarias (IAC), the California Institute of Technology and the Max Planck Institut für Astronomie, have discovered in the Orion region three giant planets and fifteen other bodies that resemble planets. The bodies are between 5 and 15 times the mass of Jupiter and are not associated with any star. Rather, they roam freely in Orion's Sigma cluster approximately 1000 light years from Earth. They are estimated to be one to five million years old. Spectra of three of the objects from the Keck telescopes in Hawaii revealed temperatures of 1700 to 2200 kelvin. After they cool sufficiently, might such bodies provide refuge for life, as Caltech's David J. Stevenson suggested in 1999?
M. R. Zapatero et al., "Discovery of Young, Isolated Planetary Mass Objects in the [Sigma] Orionis Star Cluster" [abstract], p 103-107, v 290, Science, 6 October 2000.
Robert Irion, "Giant 'Planets' on the Loose in Orion?" [summary], p 26, v 290, Science, 6 October 2000.
John Noble Wilford, "Unidentified Floating Objects: Not Quite Stars or Planets" [text], The New York Times, 10 October 2000.
Birth of Lonely Giant Planets Observed, IAC, 5 October 2000.
When is a Planet Really a Planet?, Astronomy.com, n.d.
Life-sustaining planets in interstellar space? is the What'sNEW item re Stevenson, 1 July 2000.
mothballed Mars Lander |
October 2: NASA's new Mars plan to be announced this month. The mission to return a sample from Mars could be accomplished in a variety of ways. All are under consideration after the Mars Orbiter and Mars Polar Lander missions failed in 1999. For example, Houston suggests that samples could be returned to the Space Shuttle instead of directly back to Earth's surface. The likely delay that such a change would cause is disappointing to some at Ames, like Chris McKay. One possibility, to launch the completed but mothballed Mars Surveyor 2001 Lander, is being promoted by a Connecticut aerospace engineer.
Mars Sample Return: Here's the Scoop, by Leonard David, Space.com, 2 October 2000.
Homegrown Movement to Save Scrapped Probe, by Andrew Bridges, Space.com, 2 October 2000.
Life on Mars! is the related CA webpage.
varying yeast forms grown in prion experiment |
September 27: Prions can turn on genetic programs. Two geneticists from The University of Chicago and the Howard Hughes Medical Institute have found that a prion can cause a yeast cell's translation mechanism to "read through" a stop codon and translate a previously silent genetic sequence. The researchers see the phenomenon as a needed way for duplicated genes to acquire new functions and drive evolution as Susumu Ohno suggested in 1970. They write that before this discovery, "the known mechanisms for the reactivation of inactive genes work sporadically, act infrequently and provide no obvious means for sampling coding changes in several genes simultaneously."
Prions are misfolded proteins that can cause diseases like mad-cow disease, scrapie in sheep, and Creutzfeldt-Jakob disease in humans. It came as a surprise in the 1990s that a protein — with no genetic material — can cause a communicable disease. But enzymatic proteins can initiate cascades of genetic activity; and the possibility for misfolded proteins with altered enzymatic activity to act as infectious agents has recently become accepted. Now, we welcome the new discovery that the promotion of "read-through" by prions may serve an evolutionary purpose. Thus prions align with the better-known infectious agents, viruses and bacteria, that have already begun to be recognized as having major roles in evolution.
We note another thing. Even if this discovery did achieve the solution attested, it would not advance Darwinian theory. Rather, it's one step backward, one step forward. "A major mystery in evolution" — that Darwinians have heretofore alleged to be no mystery at all — is finally acknowledged and claimed to be solved, all at once. Yet such hype reinforces the common impression that new research continues to strengthen the Darwinian account of macroevolutionary progress.
