The astronomical impact on terrestrial evolution

This is an excellent topic idea!To your point 2 regarding the largely unsupported theory that life may have come to earth in the form of microbes riding on a comet's tail or Martian meteorites, I would like to add a couple of more substantial suggestions:First, the near-ubiquitous "starseed transmissions", ie that the complex molecules which contribute much to our chemical composition are revealed by spectrographic analysis to be products manufactured by the sun, and therefore came to us either as a result of previous supernova events or else due to yet-unspecified stellar explosions or expansions on a more local level;And second, that the current best candidate for a "natural" PNA, polycyclic/nuclear aromatics (PAH), known to be common in the environment of early earth, were recently determined by similar spectro-analysis to be the product of distant nebulae; these guys are a real winner in terms of primitive information-binding, having not only a similar stacking pattern but one with the exact same "groove" size as the later, derivative molecules of nucleic acid.PAH world hypothesis - Wikipedia

Sorry I didn't link the actual discovery part beforePolycyclic aromatic hydrocarbon - Wikipedia This may have some application to your seasonal or cyclic interest, as meteor bombardments follow repetitive patterns. I regret to inform you that some of your ideas about tides may be based on myth. You can see me ranting about this a bit more here. Message 433If you use reason in this matter, you will note that the menstrual cycle of cats and dogs is quasi-seasonal rather than quasi-lunar. In other words, whatever influence these cycles may have on reproductive biology is not a result of gravitational displacement somehow being directly apparent to the animal, nor is it derived from a period when we were single-celled or genuinely amphibious; it is more recent, and varies from species to species.This becomes clearer when we look at our relatives. Primate Info Net – Wisconsin National Primate Research Center – UW—MadisonThis implies that the cycles are derived only secondarily from the moon, specifically its light; and that their primary cause is due to longterm species hunting and eating behavior. Modern chimpanzees do not hunt.

Here's the theory Here's the data And here's the controversy Cretaceous—Paleogene extinction event - WikipediaThere's a bit more here Cretaceous—Paleogene extinction event - Wikipedia

Look, you understand that that site is about Magic, right? Now here we get to something where the tidal action has a real influence. Let's take a closer look at the dark hours of the pre-dawn of the PNA world Microparticle - WikipediaNote that the amino acids form wet in the "soup". Then they have to be dry to become polypeptides. Then they have to be dissolved again to become microspheres. Further cycles of wet and dry are necessary for the best results in growing and budding.These protocells are baby genes, without NAs but copying rather than splitting. In some ways, the prions being discussed in Scripps Florida scientists show 'lifeless' prions capable of evolutionary change are a similar dealie, only reduced to parasitism. The microspheres are self-sufficient.Now let's look at where the real cell membranes come from. Abiogenesis - WikipediaThis shows a potential for tidal action to affect the formation of lipids containing these primitive proteins, which would reproduce by splitting. That's another step closer to "life as we know it."Your radioactive beaches are another good example, this time relating to the power source for nucleic acid formation. Some people prefer to point out that the existing archaea, the earliest form of "real" life, are famous as extremophiles and therefore probably developed using the energy of earth's magma. But even if this were the case, tides would still have an effect, as lava is a high-volume liquid subject to the usual gravitational displacement. Sure they can! Or at least, a lot of them. See, they are talking about the origin of various components. Which one came first, and helped the others along, is what the argument might be about. I have skipped the "sandwich" beyond mentioning archaea, but pre-enzymes came from somewhere too, somewhere before RNA.Here, have a look at this. Pre-NA WorldNote that even once "life" finishes beginning, it remains in the oceans for billions of years. Tidal displacement remains a primary influence throughout this period. Once the weeds and then critters start swarming out onto the land, they continue to have a close association with bodies of water for millions and millions more. Most still do.Edited by Iblis, : context reduced

Marine regression and increased volcanic activity. But there's a huge debate now as to how much of this was before the first impacts and how much was a result of it.Reductions in sea level wipe out marine species, reducing the food chain and oxygen supply. But many of the proposed impacts were into the ocean, so is it a cause or an effect?In much the same way, the Deccan Traps in western and central India show huge amounts of magma during this time period, indicating probably a genuine mantle plume. This sort of thing will produce catastrophic changes in the atmosphere of the whole planet. On the other hand, the Shiva crater is right off the coast there. What happens when you punch an orange? Not so much a period as an ellipse. The first impact, the iridium meteor, wreaked havoc on the biosphere. But further hits and resultant changes over the next 300,000 years are what kept them from coming back again the way they did after the Jurassic.