Register | Sign In


Understanding through Discussion


EvC Forum active members: 58 (9173 total)
0 online now:
Newest Member: Neptune7
Post Volume: Total: 917,575 Year: 4,832/9,624 Month: 180/427 Week: 93/85 Day: 0/10 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   definition of proto feathers ?
Zucadragon
Member
Posts: 91
From: Netherlands
Joined: 06-28-2006
Member Rating: 2.9


Message 1 of 10 (412415)
07-24-2007 4:56 PM


I'm not really sure where this topic should go, I'm just confused with this question, have been looking all over the place, but nowhere on the internet do I see a clear definition of what proto feathers really are.. I see a lot of texts explaining that proto feathers are used to explain something, but what are they ??
I have seen definitions describing them as:
The first feather(y) structures, evolved from scales.
Ancient feather structures.
Feathers without the Rachis.
Feathers that aren't really feathers.
I could probably go on, but yeah, that question has me confused and I hope I'm asking this in the right place.

Replies to this message:
 Message 3 by Nuggin, posted 07-24-2007 7:24 PM Zucadragon has replied
 Message 10 by arachnophilia, posted 07-27-2007 3:18 PM Zucadragon has not replied

  
AdminNosy
Administrator
Posts: 4754
From: Vancouver, BC, Canada
Joined: 11-11-2003


Message 2 of 10 (412443)
07-24-2007 6:41 PM


Thread moved here from the Proposed New Topics forum.

  
Nuggin
Member (Idle past 2570 days)
Posts: 2965
From: Los Angeles, CA USA
Joined: 08-09-2005


Message 3 of 10 (412449)
07-24-2007 7:24 PM
Reply to: Message 1 by Zucadragon
07-24-2007 4:56 PM


Lemme see if I can help
"Proto-feathers" refer to a number of feather-like structures predating the emergence of modern feathers.
It's not that they are "Feathers that aren't really feathers" but rather "feathers that do not have all the characteristics of modern feathers".
Much like a chariot could be said to be a proto-car. It doesn't have a combustion engine, it doesn't have windshield wipers, but from our perspective you can see where the technology ended up.
The first feather(y) structures, evolved from scales.
Feathers actually didn't evolve from scales, though this misconception is wide spread. There was an excellent article demonstrating feather development a few years back in (I believe) Discover Magazine. I'll try to find a link for you.
Feathers, scales and hair all utilitize the same proteins.
A lot of recent finds in China have shed a great deal of light on the development of feathers and flight.
One thing I find particularly telling is the presence of symetrical "wing" feathers on some of the fossils. Symertical feathers can not be used for flight, so obviously the development of feathers was due to some other selective force. Once feathers were in place, flight developed using what was available.
If you google feather, china and fossil, it'll get you started on dozens of article about the recent finds

This message is a reply to:
 Message 1 by Zucadragon, posted 07-24-2007 4:56 PM Zucadragon has replied

Replies to this message:
 Message 4 by Zucadragon, posted 07-25-2007 1:24 AM Nuggin has replied
 Message 7 by Wounded King, posted 07-26-2007 1:14 PM Nuggin has replied

  
Zucadragon
Member
Posts: 91
From: Netherlands
Joined: 06-28-2006
Member Rating: 2.9


Message 4 of 10 (412498)
07-25-2007 1:24 AM
Reply to: Message 3 by Nuggin
07-24-2007 7:24 PM


Re: Lemme see if I can help
Why thank you for the information , and I hopefully await the article you mentioned.
Question though, the idea that its a feather without a Rachis is plain nonsense ?, or is it so that it could be that as well, as the proto of the feather (heh) would not really be a modern feather.

This message is a reply to:
 Message 3 by Nuggin, posted 07-24-2007 7:24 PM Nuggin has replied

Replies to this message:
 Message 5 by Nuggin, posted 07-25-2007 4:58 AM Zucadragon has replied

  
Nuggin
Member (Idle past 2570 days)
Posts: 2965
From: Los Angeles, CA USA
Joined: 08-09-2005


Message 5 of 10 (412510)
07-25-2007 4:58 AM
Reply to: Message 4 by Zucadragon
07-25-2007 1:24 AM


Re: Lemme see if I can help
Still trying to find the article, but from what i recall of it, it was demonstrating feather development out of hair (hair-like) growth rather than scales.
If you could imagine hair with branches, you can are close to this concept of (very early) proto-feather.
Though, generally, where I see proto-feather used, it's in reference to things like "downy like" feather/hair on extremely well preserved fossils coming out of China.
The quality of these things is just astonishing.

This message is a reply to:
 Message 4 by Zucadragon, posted 07-25-2007 1:24 AM Zucadragon has replied

Replies to this message:
 Message 6 by Zucadragon, posted 07-26-2007 1:14 AM Nuggin has not replied

  
Zucadragon
Member
Posts: 91
From: Netherlands
Joined: 06-28-2006
Member Rating: 2.9


Message 6 of 10 (412727)
07-26-2007 1:14 AM
Reply to: Message 5 by Nuggin
07-25-2007 4:58 AM


Re: Lemme see if I can help
This makes sense of course, if they all utilise the same proteins (mostly).. So they wouldn't have a large difference between them.

This message is a reply to:
 Message 5 by Nuggin, posted 07-25-2007 4:58 AM Nuggin has not replied

  
Wounded King
Member (Idle past 110 days)
Posts: 4149
From: Cincinnati, Ohio, USA
Joined: 04-09-2003


Message 7 of 10 (412849)
07-26-2007 1:14 PM
Reply to: Message 3 by Nuggin
07-24-2007 7:24 PM


Re: Lemme see if I can help
One thing I find particularly telling is the presence of symetrical "wing" feathers on some of the fossils. Symertical feathers can not be used for flight, so obviously the development of feathers was due to some other selective force.
I'm a bit confused by what you mean by symmetrical. Aren't normal flight feathers generally considered bilaterally symmetrical, using the Rachis as the axis, while downy feathers are radially symmetrical
(Yue at al., 2006)?
Maybe I'm not thinking along the right axis.
TTFN,
WK

This message is a reply to:
 Message 3 by Nuggin, posted 07-24-2007 7:24 PM Nuggin has replied

Replies to this message:
 Message 8 by RAZD, posted 07-26-2007 2:00 PM Wounded King has not replied
 Message 9 by Nuggin, posted 07-26-2007 4:11 PM Wounded King has not replied

  
RAZD
Member (Idle past 1482 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 8 of 10 (412861)
07-26-2007 2:00 PM
Reply to: Message 7 by Wounded King
07-26-2007 1:14 PM


Re: Lemme see if I can help
Flight feather:
The Modern Apprentice - Raptor Feathers
quote:
These three feathers are Contour feathers. The feather in the middle has been placed on its side to show the real shape of these feathers and the shape that they give to the bird. The two feathers on the outside are flat and come from the wing where they describe a flat surface, but the feather in the middle comes from the bird's chest and so it is rounded describing that chest shape.
The shorter side from the rachis is the leading edge side on the two wing feathers shown. Body feathers can be symetrical.
Symmetrical feathers on the wings would be less efficient, causing more drag on the leading edges.
Enjoy.

Join the effort to unravel AIDS/HIV, unfold Proteomes, fight Cancer,
compare Fiocruz Genome and fight Muscular Dystrophy with Team EvC! (click)


we are limited in our ability to understand
by our ability to understand
RebelAAmericanOZen[Deist
... to learn ... to think ... to live ... to laugh ...
to share.

This message is a reply to:
 Message 7 by Wounded King, posted 07-26-2007 1:14 PM Wounded King has not replied

  
Nuggin
Member (Idle past 2570 days)
Posts: 2965
From: Los Angeles, CA USA
Joined: 08-09-2005


Message 9 of 10 (412876)
07-26-2007 4:11 PM
Reply to: Message 7 by Wounded King
07-26-2007 1:14 PM


Re: Lemme see if I can help
I think we're discussing 3 different possibilities.
Shaft with barbs in all directions
Shaft with barbs on two sides symetrically
Shaft with barbs on two sides but not 100% symetric
While, 1 is useless for flight (think downy feathers). 2 isn't well suited either. 3 is really what you need for wing feathers.
Think about those old timey videos of early flying machines that involved a whole lot of flapping and not much getting anywhere.
A "wing" covered in #2 feathers could be useful for controlled falling, camoflauge, maybe a dozen other things, but you wouldn't want to use while trying to take off.
Basically, the existance of purely symetrical wing feathers is a real problem for the "God poofed flying animals into existance" crowd

This message is a reply to:
 Message 7 by Wounded King, posted 07-26-2007 1:14 PM Wounded King has not replied

  
arachnophilia
Member (Idle past 1421 days)
Posts: 9069
From: god's waiting room
Joined: 05-21-2004


Message 10 of 10 (413081)
07-27-2007 3:18 PM
Reply to: Message 1 by Zucadragon
07-24-2007 4:56 PM


The first feather(y) structures, evolved from scales.
feathers did not evolve from scales. feathers evolved from hair-like structures.
however, some scales (scutes) did evolve from feathers.


This message is a reply to:
 Message 1 by Zucadragon, posted 07-24-2007 4:56 PM Zucadragon has not replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024