Post Asn9JCyvOIBRGsMj9k by jpab@mastodon.gamedev.place
(DIR) More posts by jpab@mastodon.gamedev.place
(DIR) Post #Asn8USQ4EZ0ENjrT3A by futurebird@sauropods.win
2025-04-05T20:12:07Z
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Maybe this seems basic but it constantly blows my mind. Why does nearly everything have:* two eyes on head above the mouth and smelling organ(s) (antennae "smelling organs")* the brain is in the headBasically, nearly all vertebrates & a shocking number of invertebrates have a head with a brain in it and a "face"Does this imply a common ancestor with a head with a face & two eyes? OR is this convergent?(We know that complex eyes are convergent, but did this start with simple eyes?)
(DIR) Post #Asn93MiJRJPMoz2avY by futurebird@sauropods.win
2025-04-05T20:18:24Z
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@cinebox "nearly"
(DIR) Post #Asn94LJG94c4kwmwqW by johnefrancis@cosocial.ca
2025-04-05T20:18:34Z
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@futurebird all the headbrainfaces found the other body plans gave them heeby-jeebies and ate them back during the Ediacaran
(DIR) Post #Asn9JCyvOIBRGsMj9k by jpab@mastodon.gamedev.place
2025-04-05T20:21:17Z
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@futurebird I know nothing, but Wikipedia informs me that there is a clade called Bilateria, and it's believed to have a common ancestor.Not sure about when sense organs forming a face came in, but bilateria have a front/head end.I guess once you've got a symmetric body plan then when you develop eyes you're likely to do it on your head?
(DIR) Post #Asn9Ka9UjG8zQGxrvs by gretared@sfba.social
2025-04-05T20:21:32Z
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@futurebird I mean you’d know better than me but I think the Eyes/Nose/Mouth location is for finding and eating food. Like birds who spear food have nose/beak/eyes in line. Those that scoop have the beak lower than the eyes. So I imagine it’s coincidental evolution. But again, I’m just guessing.
(DIR) Post #Asn9hRAuGwEKEzWVMW by kastope@mastodon.social
2025-04-05T20:25:40Z
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@futurebird yes. Having two eyes allows one to judge distance. Having eyes near other sensory organs lets you focus on a single thing with multiple senses at the same time. Signal processing being near the sense organs speeds up processing. All that makes a head.
(DIR) Post #Asn9tYy97SqdtBKvsO by sciolato@mstdn.science
2025-04-05T20:27:50Z
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@futurebird such a cool question! I haven’t followed this field for ages so maybe wrong. All vertebrates and most invertebrates are bilatarians which are metazoans with bilateral symmetry, meaning they have developed around a longitudinal body with a head and tail. So that basic body plan likely come from a common ancestor but details like eyes or eye stalks, like you mentioned can be from parallel evolution. #evodevo folks would know the more current thinking around this.
(DIR) Post #AsnABoFz1E8WW1NeCW by vksxypants@mastodon.social
2025-04-05T20:31:10Z
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@futurebird your post reminded me of this video which touches on the evolution of the "through gut": https://www.youtube.com/watch?v=BMoF4iupwfw
(DIR) Post #AsnBXkdJGwvBbMJl3Y by BashStKid@mastodon.online
2025-04-05T20:46:18Z
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@futurebird Maybe the interesting thing about bilateralism is how strongly it’s enforced externally versus not-so-much internally. It seems much easier to reflect the body plan and have two things rather than one, presumably tied back to early embryological genes. Then you get into a discussion of the plasticity or evolvability of linear repetition, giving you segmentation and flexibility, or amended with refusion back into platy enclosing structures.
(DIR) Post #AsnEvnbq9qmhe2myJM by michael_w_busch@mastodon.online
2025-04-05T21:24:18Z
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@futurebird Basal Bilateria was a long time ago.
(DIR) Post #AsnId2w9LV97UsbNj6 by futurebird@sauropods.win
2025-04-05T22:05:45Z
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@michael_w_busch Who are you calling "basic" ;)I guess the concept of "basic" works as well here as in fashion. Is the trait "basic" or is it "trending" ?
(DIR) Post #AsnKApq8e8Bgg4SwOe by kpaqrva@mastodon.social
2025-04-05T22:23:00Z
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@futurebird My family evolutionary biologist recommends "Your Inner Fish".
(DIR) Post #Asq2vA1mhmIiuQjVgW by lydiaconwell@todon.nl
2025-04-07T05:53:50Z
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@futurebird I did read a book about the face - not sure why.But the face is basically down to gravity. Food falls on the floor so the mouth is at the bottom to scoop it up. The nose and mouth are sometimes connected for food finding so the nose comes next. Then eyes are sensitive, so need to be kept away from the dirt, also looking out for danger. Ears are also usually at the top for the same reason.I'm no expert but I think that's the eyes above the mouth is fairly universal in species. I don't know about the brain in the head thing, but maybe faces have independently evolved in some cases.