EdEarl Posted October 10, 2016 Posted October 10, 2016 This youtube SciShow, Could Life be Older than Earth, gives a tiny bit of evidence that the panspermia seeded life on Earth. Alexi Sharov and Richard Gordon wrote Life Before Earth that is the basis of this youtube video. The paper abstract from arXiv.org (Cornell University Library) follows: An extrapolation of the genetic complexity of organisms to earlier times suggests that life began before the Earth was formed. Life may have started from systems with single heritable elements that are functionally equivalent to a nucleotide. The genetic complexity, roughly measured by the number of non-redundant functional nucleotides, is expected to have grown exponentially due to several positive feedback factors: gene cooperation, duplication of genes with their subsequent specialization, and emergence of novel functional niches associated with existing genes. Linear regression of genetic complexity on a log scale extrapolated back to just one base pair suggests the time of the origin of life 9.7 billion years ago. This cosmic time scale for the evolution of life has important consequences: life took ca. 5 billion years to reach the complexity of bacteria; the environments in which life originated and evolved to the prokaryote stage may have been quite different from those envisaged on Earth; there was no intelligent life in our universe prior to the origin of Earth, thus Earth could not have been deliberately seeded with life by intelligent aliens; Earth was seeded by panspermia; experimental replication of the origin of life from scratch may have to emulate many cumulative rare events; and the Drake equation for guesstimating the number of civilizations in the universe is likely wrong, as intelligent life has just begun appearing in our universe. Evolution of advanced organisms has accelerated via development of additional information-processing systems: epigenetic memory, primitive mind, multicellular brain, language, books, computers, and Internet. As a result the doubling time of complexity has reached ca. 20 years. Finally, we discuss the issue of the predicted technological singularity and give a biosemiotics perspective on the increase of complexity. Prior to hearing this evidence for panspermia, I thought it to be unlikely, but now it seems most probable. Is it possible the Mars sized body that hit Earth and created the Moon is the rogue planet that originally spawned life, or is a more complex chain of events more likely. Will we ever be able to simulate the chain of events to find the/a Mother planet of life that may no longer exist.
Memammal Posted October 10, 2016 Posted October 10, 2016 (edited) @ EdEarl, I find this quite fascinating. As you, I thought of panspermia as something akin to a possible contributing factor at most (perhaps explaining the origin of RNA?). This suggests something more substantial, no? I have a growing suspicion, mere speculation at this point in time, from connecting certain dots. Your post above, your other post in another thread plus some of the articles that I quoted and referenced in that same thread (below your before-mentioned post) represent some of those dots. It seems somewhat radical, so let me rather search for more dots first. Edited October 10, 2016 by Memammal
EdEarl Posted October 10, 2016 Author Posted October 10, 2016 In an infant Universe in which ambient energy makes temperature and light ideal for making life, why is it necessary to have a planet. Perhaps a droplet of chemicals of appropriate size, among trillions upon trillions of droplets, dust and gas in space coalesced into life, and subsequently landed on a planet.
Ophiolite Posted October 11, 2016 Posted October 11, 2016 I find this interesting, but insufficient for a major change in my position on the matter. I have long maintained that panspermia must be considered as a serious possibility. Why? The gap in complexity between the simplest known extant organism and the first metazoans is large and took a couple of billion years to bridge. The gap between non-life and the simplest viable living cell is arguably even larger, yet was accomplished in a couple of hundred million years or less. So, that may just have been chance: bad luck on bridging prokaryote to metazoan, good luck on bridging non-life to first life. While chance plays a large part in biology, I prefer something a little more systematic and satisfactory. Pan spermia offers such an alternative. This does not make it correct, or even likely, but it makes it a viable contender.
HB of CJ Posted October 11, 2016 Posted October 11, 2016 My first post here. How old is the Universe? How old is the Earth? Is it possible conditions in our galaxy were conductive for life 8 billion years ago? Perhaps even earlier? Now a new type of deep rock bacteria has been discovered that may in fact thrive upon radioactive decay as a food source? Life will find a way. Except for all the questions, everything is fine.
StringJunky Posted October 11, 2016 Posted October 11, 2016 (edited) I find this interesting, but insufficient for a major change in my position on the matter. I have long maintained that panspermia must be considered as a serious possibility. Why? The gap in complexity between the simplest known extant organism and the first metazoans is large and took a couple of billion years to bridge. The gap between non-life and the simplest viable living cell is arguably even larger, yet was accomplished in a couple of hundred million years or less. So, that may just have been chance: bad luck on bridging prokaryote to metazoan, good luck on bridging non-life to first life. While chance plays a large part in biology, I prefer something a little more systematic and satisfactory. Pan spermia offers such an alternative. This does not make it correct, or even likely, but it makes it a viable contender. What's wrong or missing with Earth-bound origins of life; why invoke panspermia when the former is the simplest one to consider first? Hydrothermal vents seems more likely than deep, cold space to kick things off for starters. Edited October 11, 2016 by StringJunky 2
EdEarl Posted October 11, 2016 Author Posted October 11, 2016 Wikipedia Assuming that the standard model of the Big Bang theory is correct, the age of the Universe is measured to be 13.799±0.021 billion years. Wikipedia According to radiometric dating and other sources of evidence, Earth formed about 4.54 billion years ago. IDK what the Milky Way was like 8B years ago.
Endy0816 Posted October 11, 2016 Posted October 11, 2016 I'm thinking a body similar to Europa. Still chemosynthesis but push back the 'start' time.
pavelcherepan Posted October 12, 2016 Posted October 12, 2016 What's wrong or missing with Earth-bound origins of life; why invoke panspermia when the former is the simplest one to consider first? Hydrothermal vents seems more likely than deep, cold space to kick things off for starters. Basically that ^ I've always been rather skeptical of panspermia. I mean, I agree, it has some valid points and it could happen, but that still doesn't take away the abiogenesis, because life would still have to come from non-life, and if we all agree abiogenesis must have happened somewhere at some point in time, then we just take our handy Occam's razor and start slicing and dicing. 1
Strange Posted October 12, 2016 Posted October 12, 2016 IDK what the Milky Way was like 8B years ago. The galaxy is estimated to be between 12 and 13 billion years old. It settled into its current disk form about 8 billion years ago. The rate of production of new stars had passed its peak before then. So I would guess it was similar-is to how it is now. https://www.newscientist.com/article/2079278-ageing-milky-way-stopped-making-stars-before-it-ran-out-of-gas/
johnmusic Posted October 12, 2016 Posted October 12, 2016 (edited) actually i never heard of this till now and thanks. Edited October 12, 2016 by johnmusic
Itoero Posted October 21, 2016 Posted October 21, 2016 Is it possible the Mars sized body that hit Earth and created the Moon is the rogue planet that originally spawned life, or is a more complex chain of events more likely. Will we ever be able to simulate the chain of events to find the/a Mother planet of life that may no longer exist.When the Moon got created the Earth was pretty hot, it was estimated to be 2300 Kelvin...could precursors of life survive such a heat? https://www.climate.gov/news-features/climate-qa/whats-hottest-earths-ever-been
EdEarl Posted October 21, 2016 Author Posted October 21, 2016 When the Moon got created the Earth was pretty hot, it was estimated to be 2300 Kelvin...could precursors of life survive such a heat? https://www.climate.gov/news-features/climate-qa/whats-hottest-earths-ever-been Debris left in orbit between the Moon and Earth may have taken a while to fall either into the Moon or Earth; maybe it orbited for a while before landing.
Itoero Posted October 22, 2016 Posted October 22, 2016 -Theia was an Earth trojan, it was formed during the formation of our solar system. This a hypothesis but if it's true, then it debunks that Theia brought life. I don't believe in panspermia because abiogenesis on this earth is proven to be possible. Panspermia rises a lot more questions.
Ophiolite Posted October 22, 2016 Posted October 22, 2016 Debris left in orbit between the Moon and Earth may have taken a while to fall either into the Moon or Earth; maybe it orbited for a while before landing. The impact pretty well volatalised eveything that went into orbit. Anything falling back to earth, fell back essentially instantaneously. I don't believe in panspermia because abiogenesis on this earth is proven to be possible. Panspermia rises a lot more questions. Abiogenesis on Earth has certainly not been proven to be possible. Panspermia neatly answers the question of why life appeared so soon on the planet, yet it took another 2 1/3 billion years to evolve metazoans, a much simpler step than the one from non-life to life.
Itoero Posted October 23, 2016 Posted October 23, 2016 (edited) Abiogenesis on Earth has certainly not been proven to be possible. Panspermia neatly answers the question of why life appeared so soon on the planet, yet it took another 2 1/3 billion years to evolve metazoans, a much simpler step than the one from non-life to life.There have been many experiments that show that basic building blocks of life could form in the early atmosphere. The Miller Urey was just the first one. Experiments that came after the Miller Urey used different chemicals. Something caused the universe to expand. The giant molecular cloud that created our Solar system was part of the expansion. If panspermia is correct then precursors of life evolved somewhere else and then arrived on Earth via asteroids or planetoids. Those asteroids or planetoids could not be part of our solar system. What kind of happening can cause asteroids to cross a part of the universe to crash on Earth? If asteroids did travel this far, they must have had a tremendous speed, the impact on Earth must have been more destructive then the one of Theia which makes it impossible for any life to survive. If the asteroid flew randomly, it must have fallen on the sun (the biggest gravitational pull)...this imo debunks Panspermia. Edited October 23, 2016 by Itoero
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