|WikiProject Geology||(Rated Start-class, High-importance)|
Ma? Mya? Ga?
- While I'm at it, how come there are no commas in the chart reading "4000 - 2500 million years ago"? And there seems to be no way to get in there to fix it. GeorgeLouis (talk) 14:46, 7 October 2013 (UTC)
- I have changed that odd Mya to Ma (magaannum=million years ago) but erhaps only using Ga is appropriate. In the first use of these there is an explanation in parenthesis. I am unconvinced that you need a comma in 4000. Graeme Bartlett (talk) 11:54, 8 October 2013 (UTC)
"Life" section needs to be trimmed radically
I plan to remove or radically condense much of the material in the "Life" section over the next few days -- I thought it would be prudent to allow input here before starting. Not only is the mass of material here on the origin of life a disorganized mess, it doesn't even belong in this article beyond a brief summary -- the abiogenesis article is the place for a detailed treatment of that topic. Looie496 (talk) 12:26, 31 October 2015 (UTC)
"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)
- 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)
- 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)
Start date for Archean
Red Planet X (Hercolubus) has been editing the start date for the Archean to be 3800 Mya, both in this article and in Template:Geological history. When I reverted, and asked for a reliable source, the editor provided a toolserver URL and reverted me. The current state of the article is now self-contradictory: it states both 4000 Mya and 3800 Mya.
Toolserver is not considered a reliable source (see WP:CIRC). There is a reliable source given in the article: the International Commision on Stratigraphy lists 4000 Mya as the start, as of 2013 . Is there a better reliable source for 3800 Mya? —hike395 (talk) 20:04, 12 January 2017 (UTC)
- I agree with Hike. The article cites the ICS chart as its source and we must follow it both because we have cited it and because it is the definitive offical source. Dudley Miles (talk) 22:15, 12 January 2017 (UTC)
Image: Archean landscape
@Triangulum: 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)