A team of neuroscientists from the University of Alberta highlights a significant example of convergent evolution in the brains of birds and primates like humans and apes.
Convergent evolution is defined as the process by which entirely unrelated species evolve similar traits, body forms, and organs as a result of their adaptations to similar environments or ecological functions.
The team suspects that this convergent evolution between parrots and primates gave the parrots their unique intellectual capabilities.
The SpM In Parrots
Human intelligence is attributed to an area of their brains called the pontine nuclei. This portion of the brain is responsible for transferring information between the cortex and cerebellum, the two largest areas of the brain. Together, the pontine nuclei, the cortex, and the cerebellum processed sophisticated functions among people.
According to the study published in the journal Scientific Reports on July 2, birds have small pontine nuclei. What they have is a similar area of the brain called the medial spiriform nucleus or SpM.
SpM functions in the same way that pontine nuclei do, transferring information between the cortex and the cerebellum. Hence, just like with humans, the works of the SpM, cortex, and cerebellum is important for birds to perform their unique functions.
The pontine nuclei in humans and primates are larger than other mammals. In birds, the SpM of parrots is larger than other bird species.
The team collected samples from 98 birds included in the largest collection of bird brains in the world. These samples included chickens, waterfowl, owls, and parrots.
They studied the brains they collected and observed that SpM is very large in parrots. In fact, parrots have two to five times larger SpM compared to other bird species. The team concluded that parrots may only be the bird species that may have evolved this way.
"Independently, parrots have evolved an enlarged area that connects the cortex and the cerebellum, similar to primates," said Cristian Gutierrez-Ibanez, one of the neuroscientists who worked for the study.
"This is another fascinating example of convergence between parrots and primates. It starts with sophisticated behaviors, like tool use and self-awareness, and can also be seen in the brain. The more we look at the brains, the more similarities we see."
The next step for the team is to study the kind of information that parrots processed with their SpM. Through this, Gutierrez said experts may fully understand how humans process information with their pontine nuclei.
Meanwhile, a separate team of scientists from New Zealand found another trait that separates parrot from other bird species. While most birds get the colors of their feathers from the food they usually eat, parrots rearrange the molecules in their feathers to produce another color.
Specifically, the parrots' yellow feathers can be arranged to become color red. The yellow and red feathers contain the same color pigment called the "psittacofulvins" only arranged differently.
The secret behind this color scheme lies with how the molecules are closer or farther apart. Applying the concept of quantum physics, the color scheme depends upon what is called the "energy gap." The energy gap has an influence on whether a certain wavelength of light is to be absorbed, transmitted, or reflected.
Another secret behind parrots' feathers is that some parrot species can absorb ultraviolet lights that are invisible to humans' naked eyes. After absorbing the invisible ultraviolet lights, these certain parrot species will then emit them as visible lights known as fluorescence.