goat37
Skeet, skeet!
Here is part of one post that talks about birds having the genes for making teeth. The webpage address is about 9 pages long, so just go to www.ask.com and ask the question "do birds have the genes for making teeth?" and it is the first page that it gives. I'll give more in a sec.
"There is, however, a dramatic laboratory proof of evolution that was published over a decade ago but that has never been mentioned in any general textbook with which I am familiar. Working with a phenomenon called "embryonic induction", Kollar and Fisher (Science, February 29th, 1980) were able to demonstrate that modern birds possess the genes for making teeth! The various tissues of any developing organ communicate with each other, each tissue often signaling another when and into what to develop. Thus, the outer layer of a tooth or enamel develops from an embryonic tissue called epithelium, which lines the surface of the gum, and the deeper, bone-like dentin of the tooth
derives from an underlying embryonic tissue called mesenchyme. (See diagram) Each of these tissues, the epithelium and the mesenchyme, is influenced by the other (embryonic induction). In the bird, the outer epithelial layer normally deelops into hard beak material. In a mammal such as a mouse, the same layer develops into the upper portion of the tooth (the enamel). Kollar and Fisher transplanted the deeper mesenchyme tissue from the tooth-forming region of a mouse embryo beneath the beak-forming epithelial layer of an embryonic chick.
As a result, the chick epithelium secreted tooth-enamel proteins and induced the mesenchyme to form several tooth parts, such as dentin and odontoblasts (dentin-forming cells). That is, the chick tissue made part of the tooth and participated in synthesis of the mesenchymal portions of the tooth, something which it would have been totally unable to accomplish unless its DNA contained tooth-forming genes!
This experiment proves that modern birds (specifically the domestic chicken) possess the genes for making teeth. However, birds never make teeth in nature, so one must ask where they got these genes and why they have them. The only possibly conclusion is that birds have retained genes from an earlier stage of evolution (inherited as "genetic junk") from progenitors which themselves had and used teeth. This finding is consistent with the fossil record, which indicated that birds evolved from reptiles (in particular a branch of small dinosaurs). Fossils of Archaeoteryx indicate that this 150-million-year-old animal was a "blend" of reptilian and avian (bird-like) characteristics. For example, Archaeopteryx had feathers and a furcula ("wishbone") for attachment of flight muscles like a bird, but possessed many skeletal features and teeth like a reptile. Biologists consider Archaeopteryx to be intermediate between reptiles and birds."
Actualy, forget it, I am not posting more sources... there are too many to choose from, just go research it for yourself if you think it's wrong. The burden is on YOU to disprove it.
"There is, however, a dramatic laboratory proof of evolution that was published over a decade ago but that has never been mentioned in any general textbook with which I am familiar. Working with a phenomenon called "embryonic induction", Kollar and Fisher (Science, February 29th, 1980) were able to demonstrate that modern birds possess the genes for making teeth! The various tissues of any developing organ communicate with each other, each tissue often signaling another when and into what to develop. Thus, the outer layer of a tooth or enamel develops from an embryonic tissue called epithelium, which lines the surface of the gum, and the deeper, bone-like dentin of the tooth
derives from an underlying embryonic tissue called mesenchyme. (See diagram) Each of these tissues, the epithelium and the mesenchyme, is influenced by the other (embryonic induction). In the bird, the outer epithelial layer normally deelops into hard beak material. In a mammal such as a mouse, the same layer develops into the upper portion of the tooth (the enamel). Kollar and Fisher transplanted the deeper mesenchyme tissue from the tooth-forming region of a mouse embryo beneath the beak-forming epithelial layer of an embryonic chick.
As a result, the chick epithelium secreted tooth-enamel proteins and induced the mesenchyme to form several tooth parts, such as dentin and odontoblasts (dentin-forming cells). That is, the chick tissue made part of the tooth and participated in synthesis of the mesenchymal portions of the tooth, something which it would have been totally unable to accomplish unless its DNA contained tooth-forming genes!
This experiment proves that modern birds (specifically the domestic chicken) possess the genes for making teeth. However, birds never make teeth in nature, so one must ask where they got these genes and why they have them. The only possibly conclusion is that birds have retained genes from an earlier stage of evolution (inherited as "genetic junk") from progenitors which themselves had and used teeth. This finding is consistent with the fossil record, which indicated that birds evolved from reptiles (in particular a branch of small dinosaurs). Fossils of Archaeoteryx indicate that this 150-million-year-old animal was a "blend" of reptilian and avian (bird-like) characteristics. For example, Archaeopteryx had feathers and a furcula ("wishbone") for attachment of flight muscles like a bird, but possessed many skeletal features and teeth like a reptile. Biologists consider Archaeopteryx to be intermediate between reptiles and birds."
Actualy, forget it, I am not posting more sources... there are too many to choose from, just go research it for yourself if you think it's wrong. The burden is on YOU to disprove it.
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