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Author Topic:   Archaeopteryx and Dino-Bird Evolution
Member (Idle past 93 days)
Posts: 7801
From: Manchester, UK
Joined: 05-01-2005

Message 105 of 200 (308850)
05-03-2006 5:43 PM
Reply to: Message 103 by crashfrog
05-03-2006 5:02 PM

curious note in favour of Lamarck
Darwin never held this view. In fact Darwin's work was a specific rebuttal of this form of "evolution", most prominently championed by Lamarck (and largely associated with his name.)
First of all, Darwin thought of many things that simply aren't true, such as, diet, environment, and exercise being responsible for evolutionary change
This view, regardless on who held it, turns out to have some basis in fact. Epigentics has shown that environmental factors can result in changes in offspring and grand-offspring and possibly beyond. I saw a paper that proposed that epigenetics might be behind brightly coloured warning signals of poisonous animals.
This really became interesting when it was finally shown that epigenitic effects apply to humans. A village which had several famines had smaller children during those periods (a woman's hips are smaller during famine, so she has to be able to pass a message to the embryo to not grow too much).
Not really on topic, but I thought it might be of suitable interest to the readers.

This message is a reply to:
 Message 103 by crashfrog, posted 05-03-2006 5:02 PM crashfrog has not replied

Member (Idle past 93 days)
Posts: 7801
From: Manchester, UK
Joined: 05-01-2005

Message 144 of 200 (347603)
09-08-2006 5:50 PM
Reply to: Message 129 by Someone who cares
09-07-2006 10:28 PM

Taphonomy, lagerstatte
I mean, imagine a force strong enough to fossilize feathers, ( hmmm...) and what the creature's feathers would be like from such a tremendous force
You later invite us to imagine fossilization as being as if some force pumelling the organism against semi-hard rock/mud and leaving an imprint. This is not how fossils are formed. Solnhofen is actually quite interesting:
This included placid lagoons that had limited access to the open sea and where salinity rose high enough that the resulting brine could not support life. Since the lowest water was devoid of oxygen, many ordinary scavengers were absent. Any organism that fell, drifted, or was washed into the lagoons from the ocean or the land became buried in soft carbonate mud. Thus, many delicate creatures avoided consumption by scavengers or being torn apart by currents...
The fine-grained texture of the mud silt forming the limestone from the Solnhofen area (which is composed mainly of the towns of Solnhofen and Eichsttt)is ideal for making lithographic plates...
The remains settle, and more silt is deposited on top of them. The silt continues to build and eventually hardens embedding the remains within. The remains degrade over time leaving a detailed cast of the remains that were once contained.
Its a simplification, and it misses out the permineralization that can occur to this 'cast', more details can be found here. Read around, you might find it interesting...though you might not. Take care,

This message is a reply to:
 Message 129 by Someone who cares, posted 09-07-2006 10:28 PM Someone who cares has replied

Replies to this message:
 Message 157 by Someone who cares, posted 09-08-2006 10:20 PM Modulous has replied

Member (Idle past 93 days)
Posts: 7801
From: Manchester, UK
Joined: 05-01-2005

Message 169 of 200 (347687)
09-08-2006 11:03 PM
Reply to: Message 153 by Someone who cares
09-08-2006 9:58 PM

Re: Archaeopteryx- most likely fraud, if not, still not transitional
But point is, dead birds float if they land in a lake.
Actually dead birds on a lake will either sink or get scavenged. There is an interesting study associated with this that you can read:
If birds are scavenged at sea, the number of days carcasses remain
afloat under natural conditions may be substantially shorter than
the 6 - 11 d estimate derived from these experiments. Although
scavenging of carcasses at sea has not been quantitatively
documented, it is often observed by duck and murre hunters in
Newfoundland, especially close to shore. In most instances, gulls
pick at these carcasses until they open their body cavity, at which
point internal gases can escape, bodies get water-logged, get too
heavy for gulls or other aerial scavengers to keep afloat, and sink.

This message is a reply to:
 Message 153 by Someone who cares, posted 09-08-2006 9:58 PM Someone who cares has not replied

Member (Idle past 93 days)
Posts: 7801
From: Manchester, UK
Joined: 05-01-2005

Message 170 of 200 (347714)
09-08-2006 11:30 PM
Reply to: Message 157 by Someone who cares
09-08-2006 10:20 PM

Re: Taphonomy, lagerstatte
How do you explain petrified trees found upright in the layers, protruding through "many different time periods", or a whale doing this? Doesn't a global flood and Creation better describe this?
I'll be glad to offer my views on the subject in an appropriate thread. You might want to take a look this and this.
And quoting Babu G. Ranganathan who has an obvious creationist bias doesn't help. Why don't you look to information provided by the scientists that work in this field rather than someone with a BA Minor in Biology? I assure you that you will learn more if you consider the process of fossilization from the sources that require more time to understand.
Permineralization is a second type of fossil formed. The soft tissue of the
organism decay away and the remaining hard parts are flooded with ground water.
Dissolved with in the water is calcium carbonate (calcite) or silicate. Which
ever mineral is present precipitates out and fills the pores of the long gone
organism. Cementation occurs and a "rock" is left in the place of the wood or
bone or what-have-you with an amazing amount of detail preserved as well.
Dissolution and replacement is a third type of fossilization and can be a step
wise progression from permineralization. In some cases, when the ground water
flows into the space previously occupied by the soft tissues of the organism,
the original material may dissolve away, leaving a void in the surrounding
sediments. This space, which is in the shape of the organism like a jell-0
mold, quickly becomes filled with minerals and an internal mold or "stone cast"
is formed. Replacement can occur if it is a per mineral fossil which is
dissolved and replaced by a secondary type of mineral.
source, S. Aaron Spriggs Colorado State University
I trust you will do your utmost to consider carefully the question on how fossils are known to form, and you wont just consider what the people who agree with your point of view are telling you about how they form.

This message is a reply to:
 Message 157 by Someone who cares, posted 09-08-2006 10:20 PM Someone who cares has not replied

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