[HN Gopher] Orb weaver spider glue properties evolve faster than...
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       Orb weaver spider glue properties evolve faster than their glue
       genes
        
       Author : wglb
       Score  : 35 points
       Date   : 2023-04-19 00:39 UTC (22 hours ago)
        
 (HTM) web link (phys.org)
 (TXT) w3m dump (phys.org)
        
       | MattPalmer1086 wrote:
       | Ummm, bad title. There is nothing here that suggests evolution of
       | any sort.
       | 
       | TLDR; spider glue can be produced to work in different humidities
       | by altering the ratio of proteins in it. No evolutionary
       | mechanism is discussed at all.
        
         | finnh wrote:
         | in other news, "finger positioning properties evolve faster
         | than finger genes?"
         | 
         | Doesn't seem too surprising that spiders can change their silk
         | for varying conditions. It's part of their body, after all -
         | they are going to be good at using it even in microscopically
         | different ways.
        
           | Hussell wrote:
           | The spiders haven't even been shown to change their silk in
           | response to conditions. It's just two species of spiders each
           | with their own silk recipe.
        
             | moi2388 wrote:
             | I guess physical.org also uses ChatGPT to generate random
             | headlines..
        
         | sp332 wrote:
         | The word "evolve" does not have such a narrow meaning outside
         | of a specific technical context. From the paper:
         | 
         |  _The ability to selectively express different glue protein
         | genes and /or to extrude their products at different rates
         | provides a faster mechanism to evolve material properties than
         | sequence evolution alone._
        
           | MattPalmer1086 wrote:
           | I disagree. Evolve has a general meaning that is widely
           | understood, not just in a specific technical context.
           | 
           | The fact that a spider can selectively express different
           | proteins to suit different conditions is no different to all
           | the other ways a living body can selectively alter protein
           | expression to suit different conditions. We would not
           | describe those as evolution.
        
             | moralestapia wrote:
             | >We would not describe those as evolution.
             | 
             | What do you mean by "we"? Because I happen to have degrees
             | in Genomics and Biology and I would definitely describe
             | that as evolution.
        
               | MattPalmer1086 wrote:
               | You are correct, and I misunderstood what the article was
               | saying. I just skimmed the paper itself.
               | 
               | I thought it was saying that spiders were simply
               | adjusting the material properties of their glue in
               | response to environmental conditions. This is not
               | evolution.
               | 
               | The paper is saying that while the glue genes themselves
               | are largely conserved, the material properties can vary
               | by altering the ratios of protein which are expressed.
               | 
               | Presumably this ratio is controlled due to other faster
               | evolving genes (although this is not proven by the paper
               | as far as I can see). I'm not entirely sure if they ruled
               | out whether spiders could in fact adjust their glue in
               | response to changing environmental conditions.
        
               | [deleted]
        
             | jdmichal wrote:
             | I for one definitely go grab the shotgun everytime I hear
             | that "the situation is rapidly evolving" on the news.
             | Someone has to be ready to defend against all those
             | mutants. /s
        
             | Hussell wrote:
             | Nowhere in the paper does it say that individual spiders
             | are varying their silk composition in response to
             | conditions. The selective expression of proteins is a
             | difference between the two species studied, not between
             | individuals within one species.
             | 
             | The title is technically correct: the two species share a
             | lot of glue genes, and the properties of their silks differ
             | due to other genes affecting things like the ratios of glue
             | proteins in the silk, and those genes evolved faster than
             | the glue genes themselves.
        
               | MattPalmer1086 wrote:
               | Correct, although I'm not sure if they proved that other
               | genes were responsible for the variation, just that the
               | glue genes were essentially the same between them.
        
       | dhbradshaw wrote:
       | I like to think of genes as keys on a piano. But the genome also
       | includes the a lot of the musical score. You can get a lot of
       | different songs with a finite set of keys played in different
       | combinations and sequences and amplitudes.
       | 
       | In this picture, most of evolution wouldn't be changing the keys
       | but changing the score.
        
       | Hussell wrote:
       | Since I happen to know these species: the spider pictured at the
       | top of the article is an Argiope bruennichi (Wasp Spider), a
       | European species which closely resembles A. trifasciata (Banded
       | Garden Spider, one of the two species in the study).
        
       | mkaic wrote:
       | For those who would prefer a link to the original paper instead
       | of coverage of that paper:
       | https://www.frontiersin.org/articles/10.3389/fevo.2023.10994...
        
       | pazimzadeh wrote:
       | What's not mentioned in this lay-man summary, but is mentioned in
       | the original article is glycosylation.
       | 
       | https://www.frontiersin.org/articles/10.3389/fevo.2023.10994...
       | 
       | Glycosylation is a post-translational modification that affects
       | dramatic impact on protein function, especially their
       | "stickiness."
       | 
       | There are distinct genes which are responsible for encoding
       | glycosyl transferases, which "decorate" the proteins after they
       | are made. The fact that whoever wrote this article thinks these
       | are not "glue genes" is a fallacy of composition.
       | 
       | https://en.wikipedia.org/wiki/Fallacy_of_composition
       | 
       | The article mentions that the proteins in question are highly
       | glycosylated and concludes "Divergence in material properties
       | likely also involves selective gene expression, post
       | translational protein modifications, and differences in the rates
       | of extrusion of constituent glue proteins."
       | 
       | Therefore, the title is click-bait.
        
       | [deleted]
        
       | anotheraccount9 wrote:
       | The article discusses the glue produced by orb web and cobweb
       | weaving spiders in the Araneoidea superfamily. The glue is
       | produced in specialized silk glands and is responsive to the
       | environment. Researchers compared the glue of two spider species
       | and found that both species had around 30 proteins contributing
       | to the stickiness of the glue, but the number and relative
       | contribution of each protein group differed between the two
       | species.
       | 
       | The ability to selectively express different glue protein genes
       | provides a faster mechanism to evolve material properties than
       | sequence evolution alone.
        
       | waynecochran wrote:
       | I didn't read the original article, but this write up does not
       | explain the title at all. Evolution works at the genetic level
       | does it not? What is natural selection modifying if it is not the
       | genes?
        
         | fiftyfifty wrote:
         | Someone on here recommended a book called "Wetware: A Computer
         | in Every Living Cell" and it goes into detail but at a fairly
         | layman level explaining how stuff like this works at the
         | biochemical level. Basically we have genes that code for pieces
         | of proteins and those pieces can be combined in millions of
         | different ways to form unique proteins. Feedback systems based
         | on proteins turn individual genes on and off to encourage the
         | production of effective proteins. Essentially we have the
         | ability to evolve and adapt at the protein level without any
         | modifications to our genes.
         | 
         | Honestly reading that book really opened my eyes to how complex
         | this stuff really is. Biology is unbelievably robust and
         | flexible well beyond the basic model of evolution that we are
         | taught takes places at the genetic level.
        
         | jrochkind1 wrote:
         | Same question. I could imagine a variety of answers, I don't
         | this it's exactly impossible, but yeah, the actual answer is
         | the interesting thing the title had me wanting, and not getting
         | here!
         | 
         | Or I wonder if this popular write-up article just got it's
         | title wrong?
        
         | yarg wrote:
         | Natural selection is the sieve, not the modifier.
         | 
         | That quibble aside, there are also epigenetics to consider.
        
         | Hussell wrote:
         | The two species share a lot of glue genes, and the properties
         | of their silks differ due to other genes affecting things like
         | the ratios of glue proteins in the silk. Those other genes
         | evolved faster than the glue genes themselves.
         | 
         | The title is technically correct, though misleading.
        
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