Announcement

Collapse

Message to all users:

https://carm.org/forum-rules

Super Member Subscription
https://carm.org/carm-super-members-banner-ad-signup

As most of you are aware, we had a crash to forums and were down for over two days a while back. We did have to do an upgrade to the vbulletin software to fix the forums and that has created changes, VB no longer provide the hybrid or threaded forums. There are some issues/changes to the forums we are not able to fix or change. Also note the link address change, please let friends and posters know of the changed link to the forums. For now this is the only link available, https://forums.carm.org/vb5/ but if clicking on forum on carm.org homepage it will now send you to this link. (edited to add https: now working.

Again, we are working through some of the posting and viewing issues to learn how to post with the changes, you will have to check and test the different features, icons that have changed. You may also want to go to profile settings,since many of the notifications, information in profile, also to update/edit your avatar by clicking on avatar space, pull down arrow next to login for user settings.

Edit to add "How to read forums, to make it easier."
Pull down arrow next to login name upper right select profile, or user settings when page opens to profile,select link in tab that says Account. Then select/choose options, go down to Conversation Detail Options, Select Display mode Posts, NOT Activity, that selection of Posts will make the pages of discussions go to last post on last page rather than out of order that happens if you choose activity threads. Then be sure to go to bottom and select SAVE Changes in your profile options. You can then follow discussions by going through the pages, to the last page having latest responses. Then click on the other links Privacy, Notifications, to select viewing options,the forums get easier if you open all the tabs or links in your profile, user settings and select options. To join Super Member, pull down arrow next to login name, select User Settings and then click on tab/link at top that says Subscriptions.

Thank you for your patience and God Bless.

Diane S
https://carm.org/forum-rules
See more
See less

Scales, Feathers and Hair have a common origin

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Scales, Feathers and Hair have a common origin

    Why this is significant

    1) Provides evidence of common ancestry
    2) Supports Theropod origin of Aves
    3) Shows science corrects itself when evidence demands it

    One prevailing hypothesis about the origin of hair and feathers is that they developed independenly. This is because, even though we knew, both arise from placodes, these structures had never been identified in reptiles, leading to the idea that they developed independently. Placodes in reptiles were unknown but a new paper changes that. Because unlike in mammalian and avian animals, in reptiles placodes come and go rather quickly, they've been missed. If you are not in the right microscope, looking at the right cells, with the right stain, at the right time, then you will never see them.

    This new paper reports finding placodes in crocodiles, dragon lizards and corn snakes and showing hair, scales and feathers have a common ancestor.

    The paper reads"Here, we show for the first time that the development of scales in different reptilian lineages, including squamates, is actually associated with the presence of an anatomical placode presenting all the characteristics observed in avian and mammalian placodes: (i) an epidermal thickening with columnar cells exhibiting reduced proliferation rate; (ii) typical spatial expression of placode molecular markers such as Shh, Ctnnb1, and Edar; and (iii) localized and conserved signaling in the dermis underlying the placode, such as Bmp4, readily suggesting an evolutionary developmental link with the dermal condensate observed in birds and reptiles."

    Concluding:"This set of new results coherently and conclusively indicates that most skin appendages in amniotes are homologous; that is, they all evolved from a shared common ancestor that exhibited appendages developing from an anatomical placode and expressing a set of signaling molecules still involved in the development of scales, hairs, and feathers of extant species."

    In short, the same molecular pathways that results in reptile scales when modified, can also result in the development of feathers or hair. That's how evolution works.

    [The paper also has some neat photos]

    The anatomical placode in reptile scale morphogenesis indicates shared ancestry among skin appendages in amniotes

    Most mammals, birds, and reptiles are readily recognized by their hairs, feathers, and scales, respectively. However, the lack of fossil intermediate forms between scales and hairs and substantial differences in their morphogenesis and protein composition have fueled the controversy pertaining to their potential common ancestry for decades. Central to this debate is the apparent lack of an “anatomical placode” (that is, a local epidermal thickening characteristic of feathers’ and hairs’ early morphogenesis) in reptile scale development. Hence, scenarios have been proposed for the independent development of the anatomical placode in birds and mammals and parallel co-option of similar signaling pathways for their morphogenesis. Using histological and molecular techniques on developmental series of crocodiles and snakes, as well as of unique wild-type and EDA (ectodysplasin A)–deficient scaleless mutant lizards, we show for the first time that reptiles, including crocodiles and squamates, develop all the characteristics of an anatomical placode: columnar cells with reduced proliferation rate, as well as canonical spatial expression of placode and underlying dermal molecular markers. These results reveal a new evolutionary scenario where hairs, feathers, and scales of extant species are homologous structures inherited, with modification, from their shared reptilian ancestor’s skin appendages already characterized by an anatomical placode and associated signaling molecules.
    "Kids & Adults love Fairy Tale Ark exhibit" - Ken Ham

  • #2
    This...
    https://youtu.be/Dn6dR814qo8
    ... pretty much covers it
    When evil is powerful, good men are silenced.

    Comment


    • #3
      Originally posted by Promethean View Post
      Why this is significant

      1) Provides evidence of common ancestry
      2) Supports Theropod origin of Aves
      3) Shows science corrects itself when evidence demands it

      One prevailing hypothesis about the origin of hair and feathers is that they developed independenly. This is because, even though we knew, both arise from placodes, these structures had never been identified in reptiles, leading to the idea that they developed independently. Placodes in reptiles were unknown but a new paper changes that. Because unlike in mammalian and avian animals, in reptiles placodes come and go rather quickly, they've been missed. If you are not in the right microscope, looking at the right cells, with the right stain, at the right time, then you will never see them.

      This new paper reports finding placodes in crocodiles, dragon lizards and corn snakes and showing hair, scales and feathers have a common ancestor.

      The paper reads"Here, we show for the first time that the development of scales in different reptilian lineages, including squamates, is actually associated with the presence of an anatomical placode presenting all the characteristics observed in avian and mammalian placodes: (i) an epidermal thickening with columnar cells exhibiting reduced proliferation rate; (ii) typical spatial expression of placode molecular markers such as Shh, Ctnnb1, and Edar; and (iii) localized and conserved signaling in the dermis underlying the placode, such as Bmp4, readily suggesting an evolutionary developmental link with the dermal condensate observed in birds and reptiles."

      Concluding:"This set of new results coherently and conclusively indicates that most skin appendages in amniotes are homologous; that is, they all evolved from a shared common ancestor that exhibited appendages developing from an anatomical placode and expressing a set of signaling molecules still involved in the development of scales, hairs, and feathers of extant species."

      In short, the same molecular pathways that results in reptile scales when modified, can also result in the development of feathers or hair. That's how evolution works.

      [The paper also has some neat photos]

      The anatomical placode in reptile scale morphogenesis indicates shared ancestry among skin appendages in amniotes

      Most mammals, birds, and reptiles are readily recognized by their hairs, feathers, and scales, respectively. However, the lack of fossil intermediate forms between scales and hairs and substantial differences in their morphogenesis and protein composition have fueled the controversy pertaining to their potential common ancestry for decades. Central to this debate is the apparent lack of an “anatomical placode” (that is, a local epidermal thickening characteristic of feathers’ and hairs’ early morphogenesis) in reptile scale development. Hence, scenarios have been proposed for the independent development of the anatomical placode in birds and mammals and parallel co-option of similar signaling pathways for their morphogenesis. Using histological and molecular techniques on developmental series of crocodiles and snakes, as well as of unique wild-type and EDA (ectodysplasin A)–deficient scaleless mutant lizards, we show for the first time that reptiles, including crocodiles and squamates, develop all the characteristics of an anatomical placode: columnar cells with reduced proliferation rate, as well as canonical spatial expression of placode and underlying dermal molecular markers. These results reveal a new evolutionary scenario where hairs, feathers, and scales of extant species are homologous structures inherited, with modification, from their shared reptilian ancestor’s skin appendages already characterized by an anatomical placode and associated signaling molecules.
      Since we have a creo regurgitation a YEC regurgitation/"spin" of a MSNBC article on evolution, doing NOTHING but asserting that it's really evidence for YEC, no evidence presented that their God~POOFED!~ It~ aka "The Grand Incantation DELUXE™, (evidence for this alleged Designer? an alternative scientific explanation?), a regurgitation/"spin" that's being superbly dismantled as seen here with this demolition by rogue06 (the evolution of flat-fish....seems the author omitted key details, lying by omission!), BUMP for science (the real thing!)

      It looks like science is again marching all over the God~POOFED!~ It! scenario as have our scaly friends, the fish.


      Reps!.....
      Reality rules, Honor the truth--John A. Steele *chemist99a*
      Atheism isn't a religion. It's a personal relationship with reality--Eamon Knight
      Death is nothing to us, since while we exist, death is not, and when death has come, we are not.--Epicurus

      Comment


      • #4
        Originally posted by phoenix702 View Post
        Since we have a creo regurgitation a YEC regurgitation/"spin" of a MSNBC article on evolution, doing NOTHING but asserting that it's really evidence for YEC, no evidence presented that their God~POOFED!~ It~ aka "The Grand Incantation DELUXE™, (evidence for this alleged Designer? an alternative scientific explanation?), a regurgitation/"spin" that's being superbly dismantled as seen here with this demolition by rogue06 (the evolution of flat-fish....seems the author omitted key details, lying by omission!), BUMP for science (the real thing!)

        It looks like science is again marching all over the God~POOFED!~ It! scenario as have our scaly friends, the fish.


        Reps!.....
        There are two strategies the creos take; lie about research done or ignore it.
        "Kids & Adults love Fairy Tale Ark exhibit" - Ken Ham

        Comment


        • #5
          A short write up from scidaily

          https://www.sciencedaily.com/release...0624154658.htm
          "Kids & Adults love Fairy Tale Ark exhibit" - Ken Ham

          Comment


          • #6
            Originally posted by Promethean View Post
            You take science daily as inerrant religious sacred writ. I don't. You can't get hair to grow on reptiles. ..or feathers.

            Comment


            • #7
              Originally posted by Nouveau View Post
              You take science daily as inerrant religious sacred writ. I don't. You can't get hair to grow on reptiles. ..or feathers.
              You endlessly blabber on incoherently about things you know nothing about.
              "Kids & Adults love Fairy Tale Ark exhibit" - Ken Ham

              Comment


              • #8
                Originally posted by Nouveau View Post
                You take science daily as inerrant religious sacred writ.
                Nope. NOBODY takes Science Daily as inerrant religious sacred writ.
                I don't.
                And?
                You can't get hair to grow on reptiles.
                Neither can you evos.
                ..or feathers.
                lol
                When evil is powerful, good men are silenced.

                Comment


                • #9
                  Originally posted by D Laurier View Post
                  Nope. NOBODY takes Science Daily as inerrant religious sacred writ.

                  And?

                  Neither can you evos.

                  lol
                  I want to watch a video of Darwinistas channelling their mutation goddesses. (trying)

                  Comment


                  • #10
                    Originally posted by Nouveau View Post
                    I want to watch a video of Darwinistas channelling their mutation goddesses. (trying)
                    Then create some "Darwinistas", and some "mutation goddesses". And then made a video. (attempting)

                    http://forums.carm.org/vbb/showthrea...=1#post8119110
                    When evil is powerful, good men are silenced.

                    Comment


                    • #11
                      Originally posted by Nouveau View Post
                      I want to watch a video of Darwinistas channelling their mutation goddesses. (trying)
                      is that part of your xvideos search?
                      "Kids & Adults love Fairy Tale Ark exhibit" - Ken Ham

                      Comment


                      • #12
                        Originally posted by Promethean View Post
                        is that part of your xvideos search?
                        Maybe that's how he "had the president of Mobil Oil"?
                        "My point, once again, is not that those ancient people told literal stories and we are now smart enough to take them symbolically, but that they told them symbolically and we are now dumb enough to take them literally"
                        -John Crossan

                        Comment


                        • #13
                          Nice turtle transitional to a grass pasture.

                          http://pixdaus.com/green-and-bear-it...s/view/260133/

                          No herpetology is not study of evolifestyle diseases.

                          Comment


                          • #14
                            Originally posted by Nouveau View Post
                            Nice turtle transitional to a grass pasture.

                            http://pixdaus.com/green-and-bear-it...s/view/260133/

                            No herpetology is not study of evolifestyle diseases.
                            Don't worry nouveau; nobody expect the slo-n-thick creos - no matter how many advance degrees the pretend to have - to provide intelligent commentary.
                            "Kids & Adults love Fairy Tale Ark exhibit" - Ken Ham

                            Comment


                            • #15
                              Poor cre boys, always behind the 8 ball

                              Originally posted by rook View Post
                              Gentle reader - the dinosaurian origin of birds is a biophysical impossibility.



                              Originally posted by Promethean View Post
                              Why this is significant

                              1) Provides evidence of common ancestry
                              2) Supports Theropod origin of Aves
                              3) Shows science corrects itself when evidence demands it

                              One prevailing hypothesis about the origin of hair and feathers is that they developed independenly. This is because, even though we knew, both arise from placodes, these structures had never been identified in reptiles, leading to the idea that they developed independently. Placodes in reptiles were unknown but a new paper changes that. Because unlike in mammalian and avian animals, in reptiles placodes come and go rather quickly, they've been missed. If you are not in the right microscope, looking at the right cells, with the right stain, at the right time, then you will never see them.

                              This new paper reports finding placodes in crocodiles, dragon lizards and corn snakes and showing hair, scales and feathers have a common ancestor.

                              The paper reads"Here, we show for the first time that the development of scales in different reptilian lineages, including squamates, is actually associated with the presence of an anatomical placode presenting all the characteristics observed in avian and mammalian placodes: (i) an epidermal thickening with columnar cells exhibiting reduced proliferation rate; (ii) typical spatial expression of placode molecular markers such as Shh, Ctnnb1, and Edar; and (iii) localized and conserved signaling in the dermis underlying the placode, such as Bmp4, readily suggesting an evolutionary developmental link with the dermal condensate observed in birds and reptiles."

                              Concluding:"This set of new results coherently and conclusively indicates that most skin appendages in amniotes are homologous; that is, they all evolved from a shared common ancestor that exhibited appendages developing from an anatomical placode and expressing a set of signaling molecules still involved in the development of scales, hairs, and feathers of extant species."

                              In short, the same molecular pathways that results in reptile scales when modified, can also result in the development of feathers or hair. That's how evolution works.

                              [The paper also has some neat photos]

                              The anatomical placode in reptile scale morphogenesis indicates shared ancestry among skin appendages in amniotes

                              Most mammals, birds, and reptiles are readily recognized by their hairs, feathers, and scales, respectively. However, the lack of fossil intermediate forms between scales and hairs and substantial differences in their morphogenesis and protein composition have fueled the controversy pertaining to their potential common ancestry for decades. Central to this debate is the apparent lack of an “anatomical placode” (that is, a local epidermal thickening characteristic of feathers’ and hairs’ early morphogenesis) in reptile scale development. Hence, scenarios have been proposed for the independent development of the anatomical placode in birds and mammals and parallel co-option of similar signaling pathways for their morphogenesis. Using histological and molecular techniques on developmental series of crocodiles and snakes, as well as of unique wild-type and EDA (ectodysplasin A)–deficient scaleless mutant lizards, we show for the first time that reptiles, including crocodiles and squamates, develop all the characteristics of an anatomical placode: columnar cells with reduced proliferation rate, as well as canonical spatial expression of placode and underlying dermal molecular markers. These results reveal a new evolutionary scenario where hairs, feathers, and scales of extant species are homologous structures inherited, with modification, from their shared reptilian ancestor’s skin appendages already characterized by an anatomical placode and associated signaling molecules.
                              "Kids & Adults love Fairy Tale Ark exhibit" - Ken Ham

                              Comment

                              Working...
                              X