Birds are some of the most colorful creatures in the animal kingdom. But how did birds with such amazingly different colors come about?
Almost all birds with bright red, orange, and yellow feathers and beaks use a group of pigments called carotenoids to create their color. However, these animals cannot make carotenoids directly. They must get them through their diet from the plants they eat.
Parrots are an exception to this rule and have evolved a completely new way to make a colorful pigment called psittacofulvin.
Although scientists knew about these different pigments; for a whileunderstanding the biochemical and genetic basis behind how birds use them to change color is less clear. But two separate recent studies on parrots and finches have provided important insight into this mystery.
a studywas published in current biologywas led by one of us (Daniel Hooper), and the other Led by Portuguese biologist Roberto Abore, science. Together, these provide a better understanding of how birds produce colorful displays and how these traits have evolved.
single enzyme
The two new studies involved large teams of international researchers. They used recent advances in gene sequencing to find out which regions of the genome (an animal’s complete set of DNA) determine the natural yellow-to-red color change in parrots and finches. Ta.
Remarkably, even though these two groups of birds use different types of pigments to produce their colorful displays, scientists have found that they evolved in similar ways. did.
In Arboa’s research, dusky lolly (Nicefuskata), a parrot native to New Guinea, with feather bands of yellow, orange, and red.
The study found that the change in feather color between yellow and red is associated with an enzyme called ALDH3A2. This enzyme converts the parrot’s red pigment into a yellow pigment.
The developing feathers contain large amounts of enzymes, which eventually give them a yellow color. When it gets low, it turns red.
Scientists have discovered that the ALDH3A2 enzyme also explains the color change in many other species of parrots, which have independently evolved a yellow to red color change.
two special genes
of long-tailed finch (Poephyra acticauda) is a type of songbird that lives in northern Australia. Two hybrid subspecies exist with different colored beaks. One has a yellow beak and the other has a red beak.
Most of the carotenoid pigments that birds get from their diet are yellow or orange, so the bird’s body must somehow change the chemistry of the pigments after eating them to produce the red color. yeah.
Hooper’s study looked at variation in this trait across the distribution of wild long-tailed tits, as well as variation in the measured genomes of the birds. The beak color of these finches was found to be primarily associated with two genes: CYP2J19 and TTC39B.
Together, these two genes promote the conversion of yellow dietary carotenoids to red carotenoids.
The yellow color of the long-tailed tit appears to be caused by mutations that turn off these genes, especially in the beak, but leave them on in other parts of the body, such as the eyes.
By comparing the DNA code for these color genes with other finch species, researchers found that the ancestors of modern long-tailed tits had red beaks, but a mutated yellow beak gradually became more common. I also discovered that something is wrong.
like a light bulb dimmer
Taken together, these studies show how color evolves in natural populations.
In both parrots and finches, the mutations responsible for the color change from yellow to red did not change the function of the enzymes involved. Instead, they influenced when and where these enzymes were active.
Think of it as changing the lighting in a room by attaching a dimmer to an existing light switch, rather than removing the entire light fixture.
Scientists also found that in wild populations of both parrots and finches, mutations in just a few genes can significantly change the chemical structure of the pigment, enough to produce the difference between red and yellow. It was shown that
A key gene changes the chemical structure of the dye molecule through the action of an enzyme that adds just one oxygen atom to the dye. This causes a change from bright red to bright yellow in parrots, and vice versa, from bright yellow to bright red in finches.
natural wonders
The evolution of color in birds has received attention since Charles Darwin used birds to outline his theory of evolution by natural selection. The most obvious difference between closely related birds that we see around us is their color.
These two new studies showed how the addition of a few genes and their single oxygen atom can change the course of evolution and produce new forms that look very dramatically different.
This could lead to the creation of new species, as the animals become better in an evolutionary sense, perhaps by becoming more attractive or more conspicuous to potential partners.
This work reminds us of the wonders of nature and shows that evolution is an ongoing process.
To save a species, we need to protect its genetic complexity as much as possible. Every individual in a population contains a unique genome, and every tiny difference is the product of millions of years of past evolution. In the future, this may become the key to the development of new species.
Simon GriffithsProfessor of Avian Behavioral Ecology; macquarie university and Daniel HooperPostdoctoral Researcher, Bioinformatics and Computational Biology, American Museum of Natural History
This article is republished from conversation Under Creative Commons License. please read original article.
