Post ASabnhrFjkmKvquFE0 by futurebird@sauropods.win
 (DIR) More posts by futurebird@sauropods.win
 (DIR) Post #ASabnfmZSBqSUkhTeK by futurebird@sauropods.win
       2023-02-12T02:28:59Z
       
       0 likes, 1 repeats
       
       Today my husband asked me (because he thinks I know every damn thing for some reason)"why can new life just start evolving now in some primordial soup from scratch like it did long ago? Why aren't there many different evolutionary trees with different starting points? Why one big tree?"uuuuh I have some guesses but I don't know. 🧵
       
 (DIR) Post #ASabnhrFjkmKvquFE0 by futurebird@sauropods.win
       2023-02-12T02:32:32Z
       
       0 likes, 0 repeats
       
       My guess is that:1. Life changed the composition of the atmosphere, weathering of rock, the seas everything. So it's just not the same now.2. Nothing as simple as early life, which might not even have cell walls could cut it in the hurly burly of a modern puddle. So maybe it happens but never goes anywhere.But I don't think this explains ALL life having a common ancestor as DNA suggest. Even plants and people have some common DNA. Is there some other factor?
       
 (DIR) Post #ASai6wVg5JbbbMN1oO by escarpment@mastodon.online
       2023-02-12T02:46:47Z
       
       0 likes, 0 repeats
       
       @futurebird Is the question why doesn't some "competitor" to DNA emerge- some other self-replicating molecule?Perhaps the formulation of DNA truly is a one-in-a-<extremely big number> event. Like the chances of a bunch of atoms combining into a molecule that replicates itself are so small that it is unlikely for it to happen again for eons and eons.Instead, all life is simply building off of that incomprehensibly rare event.
       
 (DIR) Post #ASai6xkxRzQFT2WkGe by gringene@genomic.social
       2023-02-12T02:57:25Z
       
       0 likes, 0 repeats
       
       @escarpment @futurebird what I'm saying in a roundabout way is that we have a single origin in part because the software we use to generate visualisations assumes a single origin.
       
 (DIR) Post #ASai6yGrXMwX3zSDzs by escarpment@mastodon.online
       2023-02-12T02:59:13Z
       
       0 likes, 0 repeats
       
       @gringene @futurebird Can you clarify? Are you using "visualization software" as a metaphor?
       
 (DIR) Post #ASai6ymPe4BEdqDQAq by gringene@genomic.social
       2023-02-12T03:08:12Z
       
       0 likes, 0 repeats
       
       @escarpment @futurebird no, not a metaphor at all.Look at any phylogenetic tree in any publication. They're pretty much all outward branching with no horizontal transfer.Even for bacteria, which we know share genes around more than... a really sharey thing.https://en.wikipedia.org/wiki/Phylogenetic_tree
       
 (DIR) Post #ASai6zNdPfxEVHd9Bw by escarpment@mastodon.online
       2023-02-12T03:13:47Z
       
       0 likes, 0 repeats
       
       @gringene @futurebird Ah ok, got it. But don't all life forms (fungi, animals, protists) have DNA? Doesn't that indicate that nature does not have another system of replication other than DNA, and DNA is the magical key that unlocked evolution?As far as I understand it, evolution depends on inheritance, variation, and struggle for survival. Seems like maybe DNA is the only mechanism of inheritance as yet realized in nature?
       
 (DIR) Post #ASai6zqLguvHwL44wq by escarpment@mastodon.online
       2023-02-12T03:06:15Z
       
       0 likes, 0 repeats
       
       @gringene @futurebird Oh I guess you don't mean metaphorically. You are suggesting that our perception of having single ancestor may be incorrect and just a failure of scientific communication where tools (software, hand drawn evolutionary trees) gloss over instances of convergent evolution?
       
 (DIR) Post #ASai6zqhfbCrxREMV6 by gringene@genomic.social
       2023-02-12T03:22:22Z
       
       0 likes, 0 repeats
       
       @escarpment @futurebird yes, as far as we know, DNA is the only thing that creates life, as we understand it.However...1. There is tentative link to the creation of a nucleic acid or amino acid world from "nothing", so it's not completely out of the realm of possibility to suggest that there were multiple origins that were spliced together.2. Nature has other non-DNA ways to replicate (fire is my favourite example), but we don't treat the things that replicate in a non-DNA as being alive.
       
 (DIR) Post #ASai70SHPtGRpyoN4S by BarrenPlanet@c.im
       2023-02-12T03:45:25Z
       
       0 likes, 0 repeats
       
       @gringene @escarpment @futurebird Replicators have to replicate with heredity, while having their populations limited by available resources, or there won't be the differential survival rates between competing variations that lead to evolution!