Helmets are not an option for these birds. Fortunately, the kingfisher’s genes may protect it when it first plunges its beak into the water.
As the name suggests, some species of these birds catch fish. To do so, they jump into ponds and rivers at high speed. How fast? It can reach speeds of up to 40 km/h (25 mph). This puts a lot of pressure on their heads. Shannon Hackett said the birds can cause concussions in humans by hitting their heads while diving over and over again. She is a curator at the Field Museum in Chicago, Illinois.
Diving species show differences in several genes that are active in the brain, eyes, and blood vessels. These data suggest that different species of diving kingfishers may have adapted some of the same methods to cope with head-first hunting. These differences may indicate how the birds respond to a hard blow to the head.
Hackett’s team made the new discovery on October 24th. communication biology.
Hackett, an evolutionary biologist, first became interested in repeated hits to the head while working on her son’s hockey team. She was worried about the effect all these beatings would have on the human brain. So she wondered how diving kingfishers protect their brains. Around the same time, evolutionary biologist Chad Eliason joined the museum. His job is to study kingfishers and their diving behavior.
Hackett, Eliasson, and researchers from a number of other organizations compared the DNA of 30 species of kingfishers. Some people drop off quickly. Others don’t. The research team took samples from birds that had been frozen in museums. Those birds came from all over the world.
Diving behavior evolved separately in different groups of kingfishers. The research team wanted to know whether species with the same behavior had similar genetic changes.When different species independently evolve similar changes, it is called convergence. For example, bats and dolphins have independently developed echolocation. (This is a way for animals to sense their surroundings using sound.) But it wasn’t clear whether plunging diving evolved by convergence.
Previous studies have shown that beak shapes converge. The kingfisher’s beak is long and pointed. This may allow you to dive underwater more effectively. Hackett wondered. [adapt to plunge-diving] Beaks, brains, and genes as well? ”
dig deep
The research team found changes in 93 genes that appear to suggest genetic convergence in diving birds. One change stood out. It’s in the gene that makes a protein called tau. Tau helps maintain cell structure. Researchers now suggest that tweaking the tau gene could help birds adapt to diving.
Tau function may become abnormal. It becomes hardened in the brain of someone who has had many concussions. Tau clumps can also signal brain diseases such as Alzheimer’s disease.
“It’s a very interesting hypothesis that they’re the same. [tau] Proteins are recycled to help kingfishers cope with strong impacts, says Tim Sackton. Although he is a geneticist, he is not involved in the new research. He works at Harvard University in Cambridge, Massachusetts.
Sackton cautioned that the study used an unwieldy type of analysis. Some of these 93 genetic changes may be due to chance. In other words, they may not be involved in the evolution of diving behavior. People will need to study these changes more closely to figure out what changes in behavior are actually involved, he says.
The next step is to test how these genetic changes affect kingfishers. One of the big questions is the impact of the protein made by the altered tau gene. Another question is how genetic differences may protect diving species.
“We still have a long way to go” to understand how genes “transform into what we see in nature,” Hackett said. But the answer here may one day be applied to protecting the human brain from concussions and brain damage.
But that’s far in the future, Hackett says. “We just started asking those questions.”
Source: www.snexplores.org
