Talk:Archean

message: "No fossil evidence has been discovered for ultramicroscopic intracellular replicators such as viruses." But didn't the genetic makeup of viruses suggest that they derive from the very earliest life forms? That virus-like creatures/entities were a middle stage between mere organic compounds and the first cellular beings? [probably not - since they are parasitic on cellular DNA they could not have arrived prior to their hosts. Books like the recent (2016)]A New History of Life have remarked this] I know there is no fossil evidence to back this up, and I'm not a biologist, but we might want to add that such things as viruses are thought to have been around throughout the Archean. Steinbach (talk) 17:06, 17 January 2016 (UTC)
replies: text: Viruses by definition are entities that don't contain all the machinery necessary for replication -- they rely on their host cells to provide the machinery they lack.  Thus viruses can't exist without host cells.  It is possible, and perhaps likely, that there was a middle stage of complexity comparable to modern viruses, but they could not have been actual viruses:  actual viruses can't exist without hosts. Looie496 (talk) 15:47, 18 January 2016 (UTC)
replies: text: I know all this, but my point is: viruses are believed to have existed in the Archean, shouldn't the article mention this fact? Steinbach (talk) 17:51, 18 January 2016 (UTC)
replies: text: Sure, if we can reference a reputable published source that states such a belief. Looie496 (talk) 02:25, 19 January 2016 (UTC)
thread_title:  Viruses 

message: It's a nice-enough image for Earth's surface, but the Moon is depicted in a much later era. We see Aristarchus much as it appears today and Copernicus as a very young crater surrounded by fresh ejecta. We also see Procellarum, of course, as it predates Copernicus. I believe Copernicus has been dated as about 800 to 900 million years old and Procellarum at about a billion. Aristarchus, so bright because of its young age today, is considered approximately 450 million years old. In any case, Aristarchus is clearly a very young feature.
It may well be that the artist, rather than speculate on what may have occupied these parts of the lunar surface in Earth's Archean eon, played it safe by depicting the Moon with the features that we know about now. However, this means the Moon seen here is far more evolved than it was then. The near side would not yet have had all those maria.— BruceK10032 (talk) 06:58, 28 April 2017 (UTC)
replies: text: Wow. I am a year late! Excuse me! I must have missed this. I'll see what I can do to make the image better and then I'll post it here for you to check if it is good. Triangulum (talk) 14:27, 14 January 2019 (UTC)
replies: text: Alright,  here's the image. Triangulum (talk) 14:49, 14 January 2019 (UTC)
replies: text:  I hate to bother you after you have already made one fix to this otherwise very nice image, but there's a bigger problem. As shown, the Moon appears to be in front of some of the background clouds. --Colin Douglas Howell (talk) 05:11, 5 May 2020 (UTC)
replies: text: Oh, you’re definitely not bothering me! I see the error. Funny how these obvious things can go unnoticed for so long. I will try to make it better very soon! Triangulum (talk) 00:10, 8 May 2020 (UTC)
thread_title:  Image: Archean landscape 

message: In the second paragraph on the geology of the eon, the following sentence is found:  "Although a few mineral grains are known to be Hadean, the oldest rock formations exposed on the surface of the Earth are Archean or slightly older."  Now, since any time "slightly older" than the Archaean is by definition part of the Hadean eon, this makes the sentence internally contradictory.  I'm not sure what the author of the sentence intended.  Should it be edited to remove the introductory clause about the mineral grains, or the final clause about "or slightly older"?  Doug (talk) 22:37, 16 April 2018 (UTC)
thread_title:  Confusing Sentence on Archaen Rocks 

message: This article asserts that "(t)he earliest evidence for life on Earth is graphite of biogenic origin found in 3.7 billion-year-old metasedimentary rocks discovered in Western Greenland." I'm not an expert on the subject, but, to my knowledge, there is now evidence of even more ancient life, dating to 4.1 Ga during the early Hadean (as reported in Bell et al. 2015)Bell, E. A., Boehnke, P., Harrison, T. M., & Mao, W. L. (2015). Potentially biogenic carbon preserved in a 4.1 billion-year-old zircon. Proceedings of the National Academy of Sciences of the United States of America, 112(47), 14518-14521. Retrieved from https://www.jstor.org/stable/26465850. The article should probably be updated to reflect this. Indianajoe13 (talk) 17:52, 29 March 2022 (UTC)
thread_title:  Origin of Life