[HN Gopher] Nocturnal bottleneck
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Nocturnal bottleneck
Author : Symmetry
Score : 90 points
Date : 2022-08-17 10:38 UTC (1 days ago)
(HTM) web link (en.wikipedia.org)
(TXT) w3m dump (en.wikipedia.org)
| tejtm wrote:
| the environment limited some traits and allowed for others; you
| (most likely) have three flavors of color cones in your eyes not
| four like birds(dinosaurs) and replies because the having more
| rods (B/W low light sensitive) was better suited to night
| survival. On the other hand our brains do not (usually) have a
| bone partition between the two halves because we did not need to
| sleep with one eye open underground.
| wizofaus wrote:
| Global warming might well gradually force us back again to a
| semi-nocturnal/ underground existence too. Bring on the night...
| prichino wrote:
| Global warming is so 2010... It's climate change
| wizofaus wrote:
| IPCC still use both terms, at least, they were last year: htt
| ps://www.ipcc.ch/2021/08/09/ar6-wg1-20210809-pr/#single-c...
|
| I wrote "global heating" first but it still feels weird to
| me.
| trhway wrote:
| >placental mammals were mainly or even exclusively nocturnal
| through most of their evolutionary story, starting with their
| origin 225 million years ago, and only ending with the demise of
| the non-avian dinosaurs 66 million years ago.
|
| i guess we're lucky that dinosaurs didn't evolve IR vision (not
| that it wasn't impossible given that snakes did get IR sense).
| thriftwy wrote:
| IR does not work for warm-blooded creatures. You will be
| jamming your own IR vision with heat coming from your body.
| That, or having eyes on beanstalks.
|
| And archosaurs were at least partly warm blooded.
| it_was_cool wrote:
| Which part is the "bottleneck"? Is it the idea that at one point
| nearly all mammals were nocturnal and that it became advantageous
| for some to transition to diurnal since there was less
| competition for resources during the day?
| rolph wrote:
| the bottleneck was a global ecosystem level of selection.
|
| dinosaurs pressured the mammals to stay small, hide in burrows,
| and roam at night.
|
| dinosaurs, and a lot of other things came to an abrupt end, the
| basal mammals survived in thier bunkers with hoards of seed,
| and were relieved of selective pressure, thus diversified in
| thier traits this is when mammalian diurnalism made a big
| comeback so they could now compete among fellow mammals radiate
| and expand niche into the estate of the late dinosaurs
| vhold wrote:
| I think it's a genetic trait diversity bottleneck? Mammals
| almost all went in the direction of nocturnal adaption and a
| lot of adaptions useful during the day were lost over time.
| Qem wrote:
| Like, mammals are very vulnerable to skin cancer. We lost
| some traits reptiles have that makes them cope better with
| UV.
| actually_a_dog wrote:
| Animals in the wild don't typically die of cancer, so
| that's probably not much of an adaptation evolutionarily.
| Even if they did die of cancer, it would likely be after
| they've reproduced, which means there's no selective
| pressure to develop the adaptation.
| moab9 wrote:
| I learned a new phrase from that article: "Burrowing
| Lifestyle".
| sph wrote:
| Mammalians being mostly nocturnal for most of their
| evolution... burrowing lifestyle. This explains people like
| me spending too much time in front of their computer in
| darkened rooms. I blame nature.
| 420official wrote:
| The bit on the photolyase DNA mechanism[1] is really interesting
|
| [1] https://en.wikipedia.org/wiki/Photolyase
| sfink wrote:
| This makes me speculate if intelligence was enabled by the slop
| available from nocturnal animals becoming diurnal. As in, perhaps
| intelligence would be much harder to achieve in a step by step
| fashion, but the adaptations to night living left some things on
| the table that enabled a random walk to intelligence: richer
| sensory input, and more energy available for processing that
| input. And perhaps faster and more flexible outputs. If
| intelligence hadn't come about, presumably evolution would have
| pushed things back towards faster / extreme sized (smaller or
| bigger) / more streamlined, basically repopulating the non-
| mammalian design points.
|
| (Note that by "intelligence" I'm not referring to human
| intelligence, just the basic form of using mental processing
| power to facilitate survival. Which is not specific to mammals,
| nor necessarily strong in all mammals.)
| [deleted]
| allemagne wrote:
| Were some of these adaptations a major factor in mammals largely
| surviving K-T?
| rolph wrote:
| its more like K-T was a bottleneck and those adaptations
| carried through the selection regime
| allemagne wrote:
| How certain can we be that that's the case? Seems like
| thermo-regulation and burrowing in particular could have been
| helpful traits in the immediate and long-term aftermath of
| the asteroid impact
| rolph wrote:
| the mammalian traits you speak of were the default mamalian
| due to pressure from the dinosaurs existence, they could
| not compete so survied in a compressed niche. when the
| dinosaurs failed to survive the bottleneck at the KT
| boundry, the mammals were in a position to weather it out
| and expand niche into a landscape devoid of most large
| dinosaur lineages, this was followed up with mammalian
| diversification founded on the small cynodont plan.
|
| this is all a tale of the fossil record and the principle
| of superposition
| cestith wrote:
| I've always had a sneaking suspicion humans, like many other
| modern mammals, may be best thought of as variable among
| crepuscular, diurnal, matutinal, and vespertine.
| [deleted]
| Gravityloss wrote:
| This explains a lot.
| paganel wrote:
| It sure does.
|
| Not that scientific but maybe a little on topic, I'm just
| reading a book about the memoirs of past Soviets leaders, and
| at some point Khrushchev is complaining how Stalin had an
| almost all nocturnal life, how for him 2AM was still "an early
| hour". Afaik Churchill was also a very nocturnal man. I'm
| wondering what other past leaders were in the same category as
| Stalin and Churchill when it comes to their night life.
| zdragnar wrote:
| It was probably the only time they could get anything done
| without constant interruption.
|
| In a past life where I was a lead of a larger team, I would
| have a fair chunk of my work day devoted to mentoring and
| meetings, and spent a few hours late in the evening doing
| actual programming work.
| pmontra wrote:
| Did they pay you to both program and lead the team? I
| realized that I didn't have any time left to program one
| week after I was given the lead of a small team. Meeting
| customers and the sales team to get requirements, design,
| explain to the team, check for progresses, etc. I could
| have been writing code at night but it was clear that my
| company didn't expect me or anybody else in my position to
| do that. I was writing code at night anyway, but on my own
| projects.
| sho_hn wrote:
| This is me, too. I start work relatively late, because it
| gives me a few hours of uninterrupted, productive work past
| "EOB" when everyone else fades out and the meetings are
| over.
| wizofaus wrote:
| I'm actually seriously worried my current role is going to
| end up like that. The annoying thing is that the meetings
| are actually quite important and useful too (undoubtedly
| some of them could be shorter). But I know it's not
| inevitable as I did manage to avoid it in previous roles as
| a principal engineer, just not sure how now!
| [deleted]
| echelon wrote:
| This hypothesis is my new go-to to explain my night owl habits.
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