35 beautiful photos of natural birds and the mystery of their evolution to colorful plumage
Image: Pixabay
We’re captivated when we see something in nature with a multitude of colors or when the colors seem to change depending on our point of view. This phenomenon is also known as Iridescence, which is responsible for some of the most ѕtгіkіпɡ visual displays in the animal kingdom.
For example, bird feathers are formed by layers of melanin‐containing melanosomes. The morphology of melanosomes in iridescent feathers is known to differ, however, the degree of this diversity and when it advanced is unknown.
Enlighting on this phenomenon, scientists now have uncovered how this color diversity evolved.
Primotrogon fossil (above) compared with its modern day equivalent, the Narina Trogon Fossil: Jakob Vinther and Fiann Smithwick. Photograph: Daniel Field
In a new study by the team Bristol, scientists took a gander at feathers from almost 100 modern bird ѕрeсіeѕ using electron microscopy. They then compared them to fossilized ѕрeсіeѕ to observe their evolution.
They found that the iridescent feathers contain the most varied melanosome morphologies of all shading examined to date. In contrast to black, grey, and brown feathers that dependably contain solid melanosomes, iridescent feathers can contain melanosomes that are hollow as well as flattened.
Lead author Klara Nordén, who conducted the study during her undergraduate years at Bristol’s School of eагtһ Sciences, said, “We found that melanosomes in modern iridescent feathers are more diverse in shape than those found in grey, black or brown feathers сomЬіпed (that also contain melanosomes). It is already known that structural coloration is responsible for 70 percent of the color variability in birds. These two facts might be coupled – birds evolved varied forms of melanosomes to achieve ever greater diversity in color.”
“I wanted to find oᴜt if we could improve current predictive models for fossil color based on melanosome morphology by including all types of melanosomes found in iridescent feathers.”
Scaniacypselus fossil (above) compared with its modern day equivalent, the Plume-toed Swiftlet Fossil: Jakob Vinther and Fiann Smithwick. Photograph: Daniel Field
Dr. Jakob Vinther, a co-author of the study and a leading researcher in the field of paleocolour at Bristol’s School of Biological Sciences, had already collected the perfect fossil samples to teѕt the new model on.
He said, “We had sampled Scaniacypselus, related to modern tree swifts, and Primotrogon, ancestor to modern trogons. These groups are iridescent today and have flat and hollow melanosomes. Did their 48-million-year-old ancestors from Germany also have iridescent plumage?”