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890M-year-old sponge fossil may be the earliest animal yet found
- gillytech 5y agoDisable javascript (easy if you're using Brave) if you want to avoid the forced email signup to read the full article.
- Andrew_nenakhov 5y agoFirefox reader mode also helps.
- gillytech 5y agoDownvote? Is this a browser war?
- Andrew_nenakhov 5y agoI actually upvoted.
- gillytech 5y agoMust have been a driveby. Cheers!
- nabakin 5y agoYou can also enter a random email. They don't verify it.
- klyrs 5y agoThis tends to be my preferred approach, because it degrades signal-to-noise that they get from the nag.
- gillytech 5y agoI don't like to enter random emails into forms. The company needlessly suffers with bad data going into their lists and ends up taxing other email providers with sends to non-existent inboxes. Unless you use a domain like example.com or something.
- dotancohen 5y agoUse the domain of the website itself.
- hanniabu 5y agoHow do we know that carbon dating is accurate for this long of time periods?
- bguebert 5y agoCarbon dating is only supposed to be accurate to about 40,000 years ago. They must be using some other method to date it, but I didn't see in the article where they say what method was used.
- athl 5y agoIn the study linked in the article, this is written: "depositional age is known through litho- and chemostratigraphic correlation with the 892 ± 13-Ma (Re–Os black shale) Boot Inlet Formation (Shaler Supergroup (Sg)), together with other geochronological constraints"
- samstave 5y agoMay you please ELI5 -- I am super fascinated by this, but I cannot decipher how to to understand this sentence.
- repler 5y agoThe age of the rocks it was found in.
- smhenderson 5y agoOK, sure, makes sense. But how do they know how old the rocks are? If not by carbon dating that is...
- dharmab 5y agohttps://www.nature.com/scitable/knowledge/library/dating-rocks-and-fossils-using-geologic-methods-107924044/ https://www.nature.com/scitable/knowledge/library/dating-roc... This page has a table of different dating methods that work on minerals and the time ranges to which they are accurate.
- pbhjpbhj 5y agoI was going to note this (first learnt about it in Capra's "Web of Life", IIRC), but they did already: >Abiotic, or nonliving, chemical processes can also form structures that look surprisingly similar to life, adds Rachel Wood, a carbonate geologist at the University of Edinburgh. "She [Turner] may be right. But I think you really have to explore and disprove all the other possibilities to make such a really strong claim like this." So for now, Wood says, "I don't think that she's really nailed that these are sponges." >Only further analysis can resolve the debate. Wood notes that crafting three-dimensional models of the tube network would help give a more detailed look at the structures. And Riding hopes the new study will inspire more scientists to take a closer look at other stromatolites to search for more of these meshy structures.
- zetalyrae 5y agoI think about this often in relation to stromatolites[0]. The earliest evidence of life on Earth ranges from immediately after liquid water appeared on the surface to one billion years after, depending on whether or not you think the specific evidence is of abiotic origin. That's a big range! If life appeared within a few million years of liquid water, it has huge implications for the probability of life elsewhere in the universe. [0]: https://en.m.wikipedia.org/wiki/Stromatolite https://en.m.wikipedia.org/wiki/Stromatolite
- MichaelZuo 5y agoPerhaps the assumption that there is a sharp, discernible, cutoff in the first place is incorrect?
- xwdv 5y agoAre there early animals we will never find because they never leave behind some sort of fossil?
- nuccy 5y agoMost of animals don't leave any fossils, especially without skeleton. Special conditions are required for fossilification [1]. 1. https://www.americangeosciences.org/education/k5geosource/content/fossils/under-what-conditions-do-fossils-form https://www.americangeosciences.org/education/k5geosource/co...
- deleted 5y ago[deleted]
- samstave 5y agoThe good news is that all modern fossils leave plenty of signatures in the form of legislation
- kadoban 5y agoMany upon many. The _vast_ majority of species are left out, and for ones that do have fossils the _vast_ majority of individuals are left out. Something getting fossilized is basically a miracle, and us finding it is another on top.
- 01100011 5y agoAbsolutely. Also consider that a vast portion of the Earth's crust has been recycled into the mantle over the millenia.
- zetalyrae 5y agoMaybe with enough technology we can drill into one of the sunken tectonic plates[0] and find fossils there. [0]: https://en.wikipedia.org/wiki/Farallon_Plate#Farallon_Plate_subduction_forms_North_American_Cordillera https://en.wikipedia.org/wiki/Farallon_Plate#Farallon_Plate_...
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- agilob 5y agoHere's a good podcast about it: https://www.nature.com/articles/d41586-021-02078-5 https://www.nature.com/articles/d41586-021-02078-5
- peterburkimsher 5y agohttps://archive.is/weU2w https://archive.is/weU2w
- calkuta 5y agoIf this site continues to feature paywalled or otherwise restricted access content, I may have to stop reading it altogether.
- redis_mlc 5y agoAn interesting idea is that if there's so many species historically, there must be a biological mechanism that helps make that possible. Something even more fundamental than natural selection.