The Developmental Theory of Feather Evolution By Jesse Seale.
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Transcript of The Developmental Theory of Feather Evolution By Jesse Seale.
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The Developmental Theory of Feather Evolution
By Jesse Seale
![Page 2: The Developmental Theory of Feather Evolution By Jesse Seale.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649d6a5503460f94a48f41/html5/thumbnails/2.jpg)
• Feathers are complex hierarchal structures with multiple interacting parts necessary for function (for example: interlocking barbules and asymmetrical rachis in flight feathers)
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• Because feathers are novel structures we see no evidence of their evolutionary history in other animals
• Because feathers are so well adapted we see no evidence of their evolutionary history in extant birds ( all primitive forms are secondarily derived)
• Archaeopteryx shows advanced asymmetrical flight feathers
![Page 4: The Developmental Theory of Feather Evolution By Jesse Seale.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649d6a5503460f94a48f41/html5/thumbnails/4.jpg)
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• Since a feathers function relies on its complex structure how did it get there?
• What where its primitive forms?• How can we know this?
![Page 6: The Developmental Theory of Feather Evolution By Jesse Seale.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649d6a5503460f94a48f41/html5/thumbnails/6.jpg)
• Developmental evolution seeks to reconstruct evolutionary history from observable developmental pathways.
• Prum and Brush in 2002 used this theory to construct an evolutionary model for feather evolution.
• Theory is supported by paleontological evidence and morphological evidance.
• Sound criticism of fossil evidence.• But, it is the most logical theory so far
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Feather Morphogenesis