Ward, Peter & Brownlee, Donald Rare Earth www.copernicus-ny.com 2000. The book has references in the back, but not footnoted in the text, so it is difficult to determine what statement is supported by what reference. The processes for the formation of the solar system and earth seem highly fortuitous and improbable. The authors do not mention God guidance in any of it. Ward is a professor of Geology and Brownlee of astronomy. The assumption of molecules to man evolution up the tree of life is evident throughout the book. The book is summarized below, and I have added a few comments.
Intro: Astrobiology is a new field that involves many disciplines: Astronomy, biology, paleontology, oceanography, microbiology, geology and genetics. Sagan and Dark who devised the drake equation(for the # of alien civilizations) that has some hidden assumptions: including once any life appears on a planet it evolves into to higher live forms. The Rare Earth book argues that there is microbial life in the universe but not higher life forms, as the conditions are not found to be right for them. They call this the rare earth hypothesis. Organic material is found interstellar clouds. Some microbes can tolerate extreme climate and conditions, but not higher life forms. Some claimed the bacterial remains were found of Mars from a meteorite. This has been challenged however. Up to 2 billion yrs of oxygen generation by algae was need for higher life on earth. In space travel life can easily be killed. Asteroid and comet impacts are a danger to life. The earth had a time period for this but is now shielded of these by the large gas planets. Our placement in the MW galaxy is good for life and unique. Many places in the MW galaxy are unsuitable for life due to low metal contents or too much radiation. Many factors making the earth are rare environment were noted. Tables are given of the many dead zones in the universe and the rare earth factors.
Chap. 1 Life might be widespread in the Universe: p.1-13 The deep sea volcanic vents have microbial life and worms nearby. Many extremophiles at 80C0, and some as high as 112 C0. p. 5 Deep drill core microbes 1500 ft in SC; 3.5 Km. in So. Africa.;often in sedimentary rocks, some in Basalt- they use C and H to form organic compounds and produce methane; called methanogens; These Archaea are autotrophs. At one time there were 5 kingdoms: Animilia, Plantae, Fungi, Protozoa and Bacteria; now it was revised to 3: Bacteria, Archaea, and Eucarya(plants, animals, portists, and fungi).p7 Most extremopohiles are archaeans, but some are bacteria. Two types of Archaea: Crenarchaeota- heat loving; and Euryarchaeota- that produce methane. Extremophiles need water, nutrients and a source of energy. Bacteria have also been found in icebergs. This leads to the assumption that microbial life may be widespread; other planets have ice and hot buried rocks.
Chap. 2 Habitable Zones of the Universe: p.15-33 Any slight variation in the parameters of the earth, sun or moon could limit our life on earth. We are at a unique location for life. The habitable zone HZ is often defined as where water is not frozen or boiled. Planets with smaller stars have smaller zones and longer life; those with larger stars have wider zones but shorter life. The CO2-silicate cycle aids maintaining the favorable climate; it removers CO2 from the atmospheres when it gets too hot and adds it when it cools. The animal life HZ is much smaller than the microbial HZ. Planets are sometimes ejected out their first orbit. This changes their HZ. Inside the planet the heat of the core radioactivity can maintain microbial life for a time, as can frozen ice. 95% of the stars in the universe are less massive than the sun. The HZ there are close to the star and this poses some dangers for life. The planets would tend to have synchrony of rotation and orbit; this would mean the same side of the planet always faces the star; this leads to extremes of heat and cold on the planet. The larger stars emit high amount of UV light which breaks down the atmosphere and is dangerous. 2/3 of the stars in our galaxy have binary or multiple stars; they are not generally good for life due to changing solar energy and gravitational effects. Variable stars are also not good for life nor are open or globular clusters. Our galaxy is about 85,000 light yrs across and our sun is 25,000 LY from the center. The center region is more dangerous with neutron stars and supernovas; the outer regions have to little heavy metals for life and for a metal planet core. Our core produces a protective magnetic field and plate tectonics. To form the heavy elements from supernovas takes time; at least 2 billion yrs. The rate of supernovas is declining with time, since our sun was formed. The Hubble deep field indicated the most distant and oldest galaxies were irregular and deformed; they were also in bubble or sheet like structures. Life has a time window in the universe. Our sun is getting brighter.
Chap. 3 Building a habitable Earth: p.35-54 The most important factors for life on earth were as follows:1. Trace amounts of C and other life elements, 2. Water on or near the surface, 3. a good atmosphere, 4. a long period of good temperatures, 5. a rich abundance of heavy elements. Any construction project requires the bld. materials to be one site for the project to begin. Pg.38 The big bang began the process. During the 1st ½ hr. elements were formed(H, He); they make up 99% of normal visible matter. H protons fused to He and this process fuels the stars. A major event was the forming of C by having 3 He atoms collide, perhaps in the red giant stars. The production of the other elements occurred after C in the cores of stars at high temperatures 10-100 million C0. Elements heavier than Bi83 are all radioactive, and most are produced by the decay of U and Th. These elements were produced in the cores of stars 10 times more massive than the Sun. The sun and some stars have about 90% H, 10% He, leavened with C, N, O at about 0.1%. Mg, Fe, Si, are at about .01% The dominate atoms on earth ware Si, Mg, Fe, and O to oxidize some of these. A high % of the earth is O; C is a trace element. The sun is unique I that it contains about 25% more heavy elements than nearby stars. Stars near the center of the Milky Way have a higher % of the heavy elements than the far out stars. The solid planets and earth are rich in heavy metals. The heavy metal content of the universe also increases with time.
Construction of Planet Earth: Stars evolve die and form; in death they become white dwarfs, neutron stars, and black holes; new stars arise from the ashes of the old. It is theorized that large mass of interstellar material formed into a flattened, rotating cloud- the solar nebula; the disk shaped mass orbiting the proto-sun. The planets formed from this nebular disk. It appears that as stars form they eject matter perpendicular to the surrounding disk, but the matter eventually ends up in the disk. The fundamental process for forming solid planets was accretion of particles that stuck together. A paradox for terrestrial planets is that if they form in the habitable zone, they usually end up with very little water, or elements like, N, C. The ice and volatile N would be not be with the other solids. Carbonaceous meteorites are thought to have been formed between Mars and Jupiter(they have up to 20% water and 4% C). The bulk of solid earth contains only 0.1% water and .05% C. A high C % would have contributed to a high CO2 and at high greenhouse effect. The light elements in comets and debris by have encountered earth and been held. A collision with a mars sized object might have vaporized the ocean and caused much CO2 to leave. These impacts would have destroyed any life; they lessened 3.9 billion yrs ago. This may have caused the earth’s tilt and rotation. It is believed that the collision with a Mars sized object also formed the moon. There is little direct information of the earth before 3.9 billion yrs, since these are the oldest rocks. Our fine tuned atmosphere is a key for life. Biological processes aid and maintain it; they generate O and remove CO2. The continents formed by volcanism and plate tectonics. P.53
Chap. 4 Life’s 1st Appearance on Earth. P. 55-85 Their assumptions of naturalism explaining everything continue here. Viruses are small but can’t reproduce alone; they need living cells. It is difficult for formulate DNA, although it could come from RNA which has only a single helix strand. During the heavy bombardment 4.4-3-9 billion yrs ago the oceans would have vaporized destroying surface life. Comets with dust, water and volatiles also hit earth raising the CO2. The earth was rotating faster and the heat from the sun less. There is some evidence in zircons about 4.2 billion yrs ago of life due to C 12/13 ratios. If there was and O2 free atmosphere, there would have been much higher UV. P62 They noted the Miller formed some amino acids, but does not discuss their handedness. Some suggest RNA formation was aided by clay crystals. They say there is no consensus on this. There is fossil evidence 3.5 billion yrs ago. Early evolutionists thought life evolve in shallow water pre-biotic soup. More recently the formation of extremophiles in hydrothermal vents is proposed; this would be a hot reducing environment. The evidence points to an early earth higher in CO2, but not with high ammonia and methane.p68 There is evidence that meteorites from the Moon and Mars reached earth; this is a possible mechanism of seeding life. There are 3 early families of microbial life: Bacteria, Archaea and Eukaryotes:(the 1st, 2nd groups have thermophiles). Gene swapping and transfer between the 3 groups may have occurred. A thermophile, Aquifex was found in the hot springs at Yellowstone Park. RNA can’t survive over 100C0.
Chap. 5 How to build animals: p.83-111 The bacteria has more than a thousand genes and the flatworm millions. The simple prokaryotic cell of a bacteria or Archaea had no nucleus and no organelles; Their genetic information is in a single strand of DNA. They solve their problem by using chemistry; they are the earliest fossils, including stromolites and cyanobacteria. Chart of 3 groups, p.88. The Eucaryans are different and more complex: They have a nucleus, organelles, mitochondria, chloroplasts and did not appear until a billion yrs later. They may have formed by endosymbiosis by taking in other organisms. A bacterium that could have done this is magneobacter, which makes organelles called magnetosmoes incorporating magnetite-Fe304 in bubbles; they line up with a magnetic field. The stromatolites produced the 02 for the early atmosphere 3-2.5 billion yrs(Gy) ago. The O in the ocean formed the banded iron formations. Also about 2.5 Gy ago the tectonic activity increased and land masses formed. Between 1-2 Gy the protists; amoeba and paramecium developed, also the multicellular algae; after 1 Gy the other eukaryotics, plants and animals developed. See chart on p. 100 How this occurred is unclear, but there are theories.p101 One theory is that sponges promoted the growth. Then worms with three tissue layers developed; they have a gut. During the Cambrian explosion there were trilobites and mollusks (quite advanced creatures) by .6 Gy. A paper by Wray used genetic dating clocks to estimate the changes: they predicted that the genetic changes occurred at about 1.6 Gy and continued to form annelids (worms) and chordates(our phylum) at .7 to 1.6 Gy. Some worm tracks have been found at 1.2 Gy, but this has been challenged. Fossil embryos of triplobasts have been found and dated at .57 Gy. There was more diversification in the Cambrian explosion at .55-50 Gy; see p.108
chart. There were also environmental changes including more O, large land masses, ice ages, and mountain bldg. the O and CO2 values changed. Ice age =.8-.6 Gy & 2.5 Gy.
Chap. 6. The Snowball Earth. P.113-124 Most astrobiologists believe that the early earth from the time of first life at 3.8-2.5 Gy was hot; most believe it was low in O, but this increased. There is evidence for glaciations from scratching of bedrock and forming tillite deposits. The major ice age began about 2.45 Gy ago and reoccurred at .8-6 Gy. After these times higher life increased. There was a lesser ice age 2.5 million to 12,000 yrs ago. This affected both the north and south hemispheres to mid latitudes. The ice age at 2.5 Gy was global to the equator and iced over the ocean: temp. -20-50 C0. It is thought this gave a reducing ocean; under sea volcanoes and contributed to a high iron and Mg. p.115 The CO2 build up escaped to the atmosphere and caused greenhouse gas warming and melting of the ice. This caused an algal bloom that generated O, and precipitation of the iron into the banded iron formations and carbonate rocks. S. Africa has large Mg. deposits dated at 2.4 Gy. P118 The sea organisms had to change to aerobic and handle oxidizing conditions, and a low iron solutions. Kirschvink held that the Archaea and Eucarya developed only after the 2.5gy ice age, but bacteria were before this. P119 At 2.1 Gy the Grypania are found as fossils. During the ice age life may have survived at the hydrothermal vents and hot surface pools. There was a 2nd glaciation at .8-.6Gy before the Cambrian explosion. P.123 gives a life temperature chart; plant and animals cant survive above 50 C0.; eukaryotic microbes not above 60 C0. Snelling noted some weakness of this ice age view(p.796). Unless there is evaporation of warm water and subsequent snow or rain fall on land there is no way to form ice and snow deposits on land. If the earth just became very cold -20-50 C0 and the oceans froze over on the top as Chap. 6 stated, how did the thick ice and snow deposits on land occur? Snelling stated there was massive volcanism that heated the oceans during the period of rapid plate tectonics as in the Baumgardner model. This would make sense. Another option would be for a frozen sea to be hit by a large meteor. However this would be a one time event, and millions of yrs of precipitation from this would be difficult to explain. The long ice age of 2.45 Gy above was after the period of heavy meteor bombardment ended.
Chap.7 The Cambrian Explosion: p.125-156 .55-.5 Gy Many groups: arthropods, mollusks, chordates; Brachiopods= small calms, trilobites=anthropods. Adam Sedgewick named it. The event took place in the sea, there were few land plants then. Some tiny organisms in the Precambrian preceded. P130 Four acts=groups followed: 1. Ediacarans: Jelly Fish(cnidarian), sea anemones, corals; figure p.134 Some put these in the early tree of life to arthropods. Others believe the Ediacarans are plants and not part of the animal tree of life(D. Seilacher of Yale); their resemblance to jelly fish is coincidental, they couldn’t swim. Grazing animals like mollusks may have eaten them.2,3. Trace fossils( only leave tracks),(Perhaps they were worms for flat worms) and Small Shellys( tiny calcareous tubes, knobs, spines)(1/2 inch about .545Gy)mineralized SSF. 4. Trilobites clams, mussels, echinoderms(.53-.5 Gy). Of these only the clams and mussels remain. The authors note that it is odd only the Eucarya evolved, not the bacteria or Archaea.p. 139 Figure on p141 shows Cambrian proceeding into the Ordovician. By this time all the major animal phyla (100) appeared. Today there are only about 28-35 phyla, as many have gone extinct. P142, 154 This was a big surprise. Factors that could have contributed to a favorable environment: 1. O2 increased greatly, 2.nutiriants (P,N, Fe) became available; bottom sediments were brought up. 3. temperatures moderated, 4. There was an inertial interchange event: rapid continental drift p.145, there were large swings in carbon isotopes, suggesting that large amounts of ocean buried carbon were brought up and exposed to the atmosphere (volcanism?).p147 Biological factors: oxidative metabolism, new body skeletons(calcified and other), large size skeletons and animals., use of food from the precambrain. Diversity implies more species, disparity different body plans. A big increase occurred in the Cambrian-Ordovician, and a 2nd one in the Cenozoic. Animals were like an ocean liner compared to the bacteria, a toy sail boat.
Chap. 8 Mass Extinctions: p.157-189 There were about 15 partial extinction events in the past 500 million yrs. the diversity of mammals was promoted by the extinction of dinosaurs 65 million yrs ago.p161 Changes to the atmosphere is the cause of most extinctions. Other causes: 1. Changing the earth’s spin rate. Some planets are tidally locked in rotation with their star and one side always faces it. 2. temp. changes out of habitable zone- runaway climate change. 3. impact of a comet or asteroid, Walter Alvarez proposed the 65 Myr Asteroid that killed the dinosaurs. He based this on iridium levels. 4. Nearby supernova within 10 parsecs (30 light yrs)- every 200-300 Myrs. 5.Cosmic ray jets and gamma rays from merging neutron stars- every several hundred Myrs. 6. Man’s activities. Frequency curves were developed by Raup based on the fossils and zoological records; has book Extinction: Bad Genes or Bad Luck. Small ones are more frequent. Reef habitats are usually affected by small extinctions, and higher animals, but not bacteria. History of extinctions: 1. The asteroid bombardment- 4.6-3.8 Gyr, 2. Advent of high O and snowball earth- 2.5-2.2 Gyr, 3. Snowball earth .75-.6 Gyr, 4. Cambrian -.56, .5 Gyr. This is a mystery.p178, 5. Ordovician and Devonian- .44,.37 Gyr. Causes also a mystery. P179 6. Permian-Triassic -250 Myr. Most severe; see p. 141 The cause is also unsure- proposed out gassing on CO2 from ocean sediments contributed to toxicity and global heating.(perhaps the continents formed one large super continent).p184 50% of marine life died, 80-90% of species died. 7. End Triassic -202 Myr; possible asteroid: Manicouagan crater in Quebec is 100 Km diameter. 8. Cretaceous/Tertiary boundary- 65 Myr. Alvarez hypothesis of asteroid: Chicxulub crater(200 Km) in Yucatan Mexico; caused blackout for several mo.; much of plant life died; high iridium at C/T boundary, also soot, probably fire on most of earth; Dinosaurs and 60% of species die. p 157-8 Five biggest family extinctions: 54% for Permian, 25%,Ordovician, 32% Triassic, 19% Denovian, 17% for C/T(K/T). Cambrian, 60% biggest of all. See p. 357 Snelling differs: He noted that the extinction peaks occur for both marine and terrestrial life. The P/T was the biggest, then the C/T (K/T) and then the Cambrian. Although most dinosaurs disappeared at the K/T, many terrestrial species survived- frogs, lizards, salamanders, crocodiles, alligators and turtles also teeth of dinosaurs have been found above the K/T. The marine extinctions at the K/T are more severe; p358 Snelling His charts of sea level changes are noted in Fig 19,38 p448,464. He stated the major changes are well accepted by geologists. This show the sea level lowest in the pre-Cambrian, rising very high during the Cambrian (due to the flood), then dropping slowly during the Paleozoic and most of the Mesozoic 9 (due to flood depositions and dropping water levels and continent plate tectonics –continents separating and some mountains raising-Snelling stated this is when most of the fossils and sedimentary layers were deposited), The C/T boundary is again a high sea level, actually occurring in the Cretaceous. My thought: The ice age could be in the Jurassic as ice has more volume that water and it is lighter than rock and on top of the land; Snelling noted p.785 that the sea level dropped 50-60 M due to the ice being locked up on the land. When the ice melted the seas rose again as in the Cretaceous. It could be that a meteor also struck causing heating and melting of the ice., The final sea dropping to near present was due to further mountain building and sea bottom changes. The land areas that had been covered with ice rose due to isostatic rebound due to the loss of the ice weight p.788 Snelling. References on iridium: http://www.scn.org/~bh162/iridium.html, http://en.wikipedia.org/wiki/Iridium It was noted that asteroids have high iridium as does volcanic emissions, and the earth core. There is a slightly elevated iridium clay layer at the K/T.
Chap. 9 The Importance of Plate Tectonics, PT: p.191-220 Plate tectonics is the cause of the mtn. chains on earth; they are not found on other planets. The earth has a radioactive interior that generates heat(p196) and melts the core. The mantle layer is somewhat plastic and is overlain by the plates. The division is the 1400C isotherm.p197 the plates are 50-60 km thick at the oceans and 100 km thick over the continents. The melted rock(magma) forms chocolate to black basalt. It is denser than the continents of granite and andesite which have more silica. The Cascade mtns. and Aleutian Is. are examples formed by subduction and PT. The continents are not generally destroyed but continue rising; they can erode or split however. The ocean crust can sink but not the continents they float.p.201 Some believe that the continent formation period was rapid in the early earth history, as the process was accelerated. At some areas like the mid-Atlantic ridge new magma is continually added. The continent formation and separation process driven by PT promoted biodiversity. There is a carbonate and CO2 cycling process promoted by tectonics: Weathering cause erosion of CaSiO3 that reacts with CO2 to form CaCO3 limestone. This gets subducted, then melted and CO2 is out-gassed at volcanoes. As the earth spins there is circulation in the liquid iron core that produces the magnetic field. The loss of heat from the core contributes to the circulation. The heat is brought to the surface aided by PT. P213 The oceans also aid PT. The details of the driving of PT are not well understood. Scientists model it.p.214 It is thought that there was a rapid continental formation about 2 million yrs ago in the Archaean era preceding the Cambrian explosion.(p.216). The moon may have also influenced the process.
Chap. 10 The Moon, Jupiter and Life on Earth. p221-42 They play vital roles. There are few earth like planets with big moons. The gas giant planets have moons; Jupiter with 4.The moon plays a vital role in keeping the earth tilt of 230 and the tides. The tilt is optimum and key for a varied climate. The moon is slowly moving outward at 4 cm/yr. High tides are at full and new moon. After initial formation the moon may have been only 15,000 mi. away from earth. This would have caused huge tides and earth heating. Now the water bulge precedes the moon in rotation and is in the same direction of rotation as the earth. The Devonian corals indicate the earth was rotating faster (400 days in a yr). The most accepted theory of the moon’s origin follows: A planet the size of mars collided with earth on an angle and then after some admixing they separated. The great heat melted the iron which all went into the earth’s core. The more volatile elements(zinc, cadmium, tin) are absent from the moon. It accumulated solids by accretion after the split. It is very dry but has sticky dust on the surface. Both the earth and moon are depleted of the siderophile elements(platinum, gold, iridium). The moon is much less dense than the earth, but their surface trace element and isotropic composition is very similar. An iron core formation requires high internal temperatures, to melt and segregate the elements. It is thought that there was a build up of radioactive uranium, thorium, and potassium in the core that produced heat. If the impact had not occurred at all the earth may have had a much higher content of water, carbon and nitrogen. My note: The disposition of the water was not discussed.
http://nineplanets.org/overview.html
The inner solar system contains the Sun, Mercury, Venus, Earth and Mars: The main asteroid belt (not shown) lies between the orbits of Mars and Jupiter. The planets of the outer solar system are Jupiter, Saturn, Uranus, and Neptune (Pluto is now classified as a dwarf planet):
ore terrestrial or rocky planets: Mercury, Venus, Earth, and Mars:
- The terrestrial planets are composed primarily of rock and metal and have relatively high densities, slow rotation, solid surfaces, no rings and few satellites.
- jovian or gas planets: Jupiter, Saturn, Uranus, and Neptune:
- The gas planets are composed primarily of hydrogen and helium and generally have low densities, rapid rotation, deep atmospheres, rings and lots of satellites
http://en.wikipedia.org/wiki/Comet
- Short-period comets originate in the Kuiper belt, or its associated scattered disc,[1] which lie beyond the orbit of Neptune. Longer-period comets are thought to originate in the Oort cloud, a spherical cloud of icy bodies in the outer Solar System. Long-period comets plunge towards the Sun from the Oort cloud because of gravitational perturbations caused by either the massive outer planets of the Solar System (Jupiter, Saturn, Uranus, and Neptune), or passing stars.
Jupiter J (p.235) is a gas giant of mostly hydrogen H and helium, with a H core. J. protects earth from asteroids and comets. J is 10 times larger and 300 times heavier than earth. Mars is smaller than earth and lacks a magnetic field and an atmosphere. There was a period of heavy bombardment of earth and Mars with asteroids in which the ocean may have been vaporized.P.237 Mars water may have been lost to space. It is possible that there way early microbial life on Mars that seeded earth. Mars in ½ the size of earth and 1/10 the mass. J is thought to have formed with ice that accumulated and then attracted much gas, H and helium when it reached 15 earth masses. My note: They did not say where the 15 earth masses of water went. It may have been ejected. When other gas giant planets are found in the universe they are often nearer their sun than J and it is difficult to explain how they formed there; perhaps they formed out in colder distant regions and then migrated closer to their sun. p.241-2
http://en.wikipedia.org/wiki/Jupiter
Jupiter is primarily composed of hydrogen with a quarter of its mass being helium; it may also have a rocky core of heavier elements. Because of its rapid rotation, Jupiter’s shape is that of an oblate spheroid (it possesses a slight but noticeable bulge around the equator). The outer atmosphere is visibly segregated into several bands. There are also at least 64 moons, including the four large moons called the Galilean moons that were first discovered by Galileo Galilei in 1610. Ganymede, the largest of these moons, has a diameter greater than that of the planet Mercury. Ju Hi; have you seen my apologetics book: Evidences for God and his Creations, and web site: http://creationapologetics.net Hi; have you seen my apologetics book: Evidences for God and his Creations, and web site: http://creationapologetics.netpiter has been explored on several occasions by robotic spacecraft, most notably during the early Pioneer and Voyager flyby missions and later by the Galileo orbiter. The most recent probe to visit Jupiter was the Pluto-bound New Horizons spacecraft in late February 2007. The probe used the gravity from Jupiter to increase its speed. Future targets for exploration in the Jovian system include the possible ice-covered liquid ocean on the moon Europa. Jupiter’s upper atmosphere is composed of about 88–92% hydrogen and 8–12% helium by percent volume or fraction of gas molecules (see table to the right). Since a helium atom has about four times as much mass as a hydrogen atom, the composition changes when described as the proportion of mass contributed by different atoms. Thus the atmosphere is approximately 75% hydrogen and 24% helium by mass, with the remaining one percent of the mass consisting of other elements. The interior contains denser materials such that the distribution is roughly 71% hydrogen, 24% helium and 5% other elements by mass. The atmosphere contains trace amounts of methane, water vapor, ammonia, and silicon-based compounds. There are also traces of carbon, ethane, hydrogen sulfide, neon, oxygen, phosphine, and sulfur. The outermost layer of the atmosphere contains crystals of frozen ammonia.
Chap. 11 Testing the Rare Earth Hypothesis: p.243 That microbes are common but advanced life is not in the universe. The earth radiates infrared radiation back into space; this has water vapor, ozone and CO2 peaks. Thus spectral analysis of the atmosphere is a good way of sensing life. The water vapor depends on the temperature and the availability of water; ozone comes from the interaction of O and UV and is protective for radiation. NASA has Terrestrial Planet Finder planned using this technique. A second approach is the SETI project that looked for radio signals; it has not found any. Disadvantageous of this include the vast distances and the timeliness of communication. Microbial life has not been confirmed on either Mars or the moon, although they have been explored. The moons of Jupiter, mainly Europa, are candidates for life. Europa has a frozen ocean.
Chap 12. Assessing the Odds: p257 There is a theory of planet formation in feeding zones; but observations do not back up the theory well.p259 Water is needed for life; but it is not abundant in the inner regions of the solar system but is present in the outer areas. Perhaps water was added to the earth by comet bombardment. CO2 is needed for life and can be removed by limestone formation in the sea; a large see, shallow land areas and plate tectonics promote this. Thus plate tectonics and a large moon aid life and climate. The earths rotation and axis tilt stability is aided by the moon. The original Drake equation did not consider all of these factors and had highly optimistic estimates. Sagan estimated 10 planets per star, but this is now shown too be high. The detected planets are gas giants like Jupiter and it appears that only 5-6% of the stars have planets, they appears as gas giants and have elliptical orbits. Such orbits do not promote life; they tend to remove rock planets or drive them into their sun. The most common stars are M stars and they promote a too small habitable zone for life. The very large stars have a short life. When this is taken into account, only 1- .001 % of the stars would have planets with habitable zones. On the earth it took 4 billon yrs to form humans with radio telescopes. When all these factors are taken in account the Drake equation can approach zero as a predictor of life planets rather than the million planets Sagan noted.
Chap.13 Messengers for the Stars: p.277 They again note that our earth is a rare and unique planet. P.282 The earth’s biodiversity is decreasing and the human population increasing; the rainforests are disappearing. In 1998 we received radiation from a magnetar- neutron star; our magnetic field and atmosphere stopped most of it. We have much to learn about the universe and are at the beginning of learning things.
Tofflemire discussion using other references: The Rare Earth appears completely naturalistic. If one uses a biblical outlook how would one square the findings of the Rare Earth? Comments will begin on the Introduction and Chap.1: Ross (1,2)asserted, that organic molecules have been found in space and space objects, but no amino acids and no life. Bacterial life was alleged on Mars and on asteroids, but this has not been proven. If life is found on Mars, it could be from projectiles that came from earth. Ross also noted (1Chap.13) that early extremophilies did exist as did bacteria. However there is no evidence that they preceded bacteria. Ward also did not cite them as prior, but proposed some unknown common ancestor. Ross noted: If extremophiles were first, they would have evolved into mesophiles that live at moderate temperatures. This transition is difficult to imagine in changing from extracting energy from inorganic chemicals to energy from organic foods. Thermophiles do not tolerate this transition. Ross (1-Ch12):
Chap. 12 Life’s Minimum Complexity p 160-8 Recently molecular biologists have used a top down approach to track life forms. They are discovering new genomes and tracking them back to the most similar prior ones called the LUCA (last universal common ancestor). This has proceeded to identify the near beginning, the simplest functional bacteria. For a bacteria to survive independently, it requires about 1500 gene products. p161 Parasites live off of other organisms and need at least 500 genes; but they can’t perform certain life functions and are thus not independent. The cyanobacteria found in early fossils, have about 1700 genes. As noted previously, even one protein with its 20 amino acids is considered impossible to form correctly by chance, let alone 1500 genes. The probability of 1500 genes forming correctly by chance is one in 10112500. Not only must the genes form, but also the DNA, RNA and cell wall are needed. Prior to the 1990’s the bacteria was thought simpler, bet it is now known to be complex and impossible to form by chance. In summary life can’t form by chance; it can be moved.
No comments are offered on Chap 2,3,4, other than it alls seems very magical and improbable that all of this could have occurred by chance. It seam more likely that as Ross implies, God fined tuned, guided an created many of the events. I would agree that the earth would have to be made habitable and with oxygen for advanced life to form
Comments on Chap. 5. Ward noted that the Eucaryans are much more complex than the prokaryotic cells. Many authors (3,4,5,6) have noted that there is no documented mode of upward evolution to greater complexity and it is highly improbable. Only small changes within species to new species with slight variations have been observed. Random mutations are usually detrimental, and sometimes neutral, very rarely beneficial.
Chap. 6 Comments using Selling are at the end of the Chap. notes.
Chap. 7 Comments: Ward noted that the Cambrian explosion produced 100 phyla and this is much more than we have today. To me this argues that God created them as it is highly improbable the chance could do it.
Chap. 8 Comments: My comments are noted at the end of the Chap. There is a slightly elevated iridium clay layer at the K/T supporting the asteroid extinction. Volcanic emission can also yield iridium. Snelling also noted that.
Chap. 9 The Importance of Plate Tectonics Comments: Ward acknowledges that some geologists believe that the continent formation period was rapid in the early earth history, as the process was accelerated; also the driving force is not well understood. I favor the rapid PT model devised by Baumgartner and noted by Selling. Several web references do support radiation as a major source of heat in the earth’s core: http://www.physorg.com/news62952904.html, http://www.universetoday.com/52027/earths-core/
Chap. 10 Some internet research was added for this Chap. No comments are offered on Chap. 11,12,13. It is noted that that there is evidence of early microbial life, sea organisms and worms on earth much before the advanced life; these and plate tectonics aided the atmosphere changes that aided life. Microbial life can tolerate much more change environmental conditions than advance life and survive.
References Cited:
1. Rana, F. and Ross H. Origins of Life, Navpress, Colorado Springs, 2004
2. Ross, H. Why the Universe is the Way it Is. Baker Books, Grand Rapids, MI. 2008.
3. Parker, Gary. Creation Facts of Life How Real Science Reveals the Hand of God, Green Forest, AK., Master Books, (2008)
4. Patterson, R. Evolution Exposed Answers in Genesis, Hebron, Kentucky(2007)
5. Sanford, J.C. Genetic Entropy, FMS Publications, Waterloo, NY 2008
6. Sarfati, J. Refuting Evolution. Master Books, Inc, Green Forest, AR. (2003)
7. Snelling, A. Earth’s Catastrophic Past, Geology, Creation & the Flood, Vol 1-2 ICR 2010
8. Baumgardner, John Global Tectonics and the Flood DVD from Answers in Genesis 2006