Chicken scales turned to feathers (again). Two scientists at University of Geneva have used a gene stimulating technique to get chicken embryos to develop feathers on their feet and legs instead of scales. The method involved stimulating genes named Sonic Hedgehog (Shh), which have an important role in organising and developing body organs and structures during embryonic development.
Some chicken breeds are known to have feathers on their legs, but researchers chose a breed that normally has scaly legs and feet. When the treated embryos were fully developed and hatched they had tiny downy feathers on their legs and feet. When they matured into adults they formed adult feathers on their legs.
One of the researchers, Michel Milinkovitch, commented: ‘‘Our results indicate that an evolutionary leap -from scales to feathers – does not require large changes in genome composition or expression. Instead, a transient change in expression of one gene, Shh, can produce a cascade of developmental events leading to the formation of feathers instead of scales.’’
Editorial Comment: Those who want to use this study to support the idea that dinosaurs with scaly skin evolved feathers in anticipation of evolving into birds can forget it. This non-evolution is confirmed by the fact that some chicken breeds are already known to grow feathers on their legs.
Sonic hedgehog genes organise what structures are built where during embryonic development, i.e. they activate other already existing genes. They do not produce new genes, as would be needed to turn a scaly creature with no feathers into a feathered creature. These experimental chickens only produced feathers on their legs because they already have the genes to make feathers. Every cell in a chicken’s body has the genes for making feathers, but they are only activated in some places. All that has happened in this experiment is that chickens are growing feathers in places they normally do not because the feather building genes have been activated in a different place.
In case those with long memories are wondering – yes, Sonic hedgehog genes are named after an animated character named Sonic the hedgehog, and yes, there have been previous experiments to achieve the same results going back to the early 1980’s.
Creation Research New 21 June 2023
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