Young beetles participate in sibling rivalry when they compete for the attention of parents as well as children.
Young beetles participate in sibling rivalry when they compete for parental attention as well as children, scientists say
- Sibling rivalry is common within animal families, including the burial beetle
- US scientists UU. And the United Kingdom studied two samples of the error, with and without parents
- Insect larvae with parental care have evolved to be more competitive, the team said
- But the presence of parental care can also determine whether young insects cooperate
Sibling rivalry is not only common in human families, but also in beetles.
A new study suggests young beetles of the common sexton beetle (Nicrophorus vespilloids) compete with each other when it comes to receiving attention from their parents.
A team of researchers, led by Darren Rebar, from Emporia State University in Kansas in the United States, studied 22 generations of the buried beetle to get more information about family interactions within the species.
These insects are seen as ‘the undertakers of the animal world’, as they bury dead and decaying animals, such as mice and small birds, and, even more horribly, feed on their bodies.
Scroll down to watch the video
Nicrophorus vespilloides tomb beetle larvae develop in the absence of parental care
Parental care can vary among populations of sexton beetles, and some parents continue to care for their young until they reach the larval stage, while others leave shortly after laying eggs.
In two of the experiments, the authors separated the parents from their offspring to examine their behavior.
They discovered that the young beetle brothers who took care of their parents were more competitive with each other, while those who did not receive attention seemed to be more cooperative.
In general, when parents provide attention, a behavioral response in multiple species is to exhibit higher levels of competence for the resource that adults provide, in the form of movements towards parents, for example, or aggression against their sibling rivals.
This can sometimes result in ‘siblicida’, the death of a little brother, which can actually benefit the surviving offspring and the parents.
After 22 generations, the authors created mixed offspring of newborn larvae and measured the larvae weight after five days as an indicator of physical fitness.
The larvae of the entire care populations showed evidence of competence, but when the parents stopped caring for their descendants, the rival brothers began to cooperate with each other.
The findings are parallel to human siblings who could begin to help each other in the family home when parents are absent.
It can be seen that this cooperation compensates for the lack of care of the parents and helps the survival of the other.
“The rapid evolutionary change between sibling rivalry and sibling cooperation is possible because siblings induce higher levels of rivalry (or cooperation) between them,” the authors wrote in procedures of the National Academy of Sciences.
The larvae of the sepulchral beetle Nicrophorus vespilloides (pictured) as they appear while being attended by an attentive father
“This generates positive evolutionary feedback, quickly blocking the larvae at higher evolutionary levels of competition or cooperation, in the presence or absence of parental care.”
Then, the researchers created mixed offspring to contain the same number of cooperative and competitive larvae.
They discovered that once the majority of the offspring in a offspring began to express cooperative or competitive behavior, they induced higher levels of cooperation or competition, respectively, in the rest of the group.
The scientists said that both parental strategies, whether caring for their children or letting them manage alone, can “increase an individual’s genetic fitness.”
“In the natural populations of burial beetles, it is likely that the provision of care fluctuates greatly from one generation to the next, maintaining a mixture of cooperative and competitive larvae and thus avoiding any evolutionary leakage to purely competitive or purely cooperative offspring,” he says. the study.