As you bite a chocolate rabbit or egg this weekend, consider this: rabbits often eat their own young, chickens and their eggs.
In fact, eating or abandoning a child has been documented in a variety of mammalian species and birds – as well as fish, insects and spiders. Hunger and quality control are among the many reasons offered for the anti-intuitive exploitation of natural selection.
Now, researchers from the University of Tennessee and Oxford University suggest that in some cases, infant cannibalism and taking offspring can also be considered forms of parental care. Posted in Boundaries of ecology and evolution, Their mathematical model shows that when overcrowding threatens the survival of offspring – which often occurs due to the spread of pollution or competition over resources – some sacrifice so that the majority can live the ultimate form of tough love.
Put all eggs in one basket
To understand the role of overcrowding or "child density" in the survival benefit of infant cannibals, the researchers focused on species that lay eggs.
"Laying community eggs is common in a variety of fish, insects, reptiles and amphibians," says senior author Dr. Hope Kellogg, associate professor at the University of Tennessee, Tnoga, "It makes it easier to protect, clean, incubate and feed the eggs – But can also increase disease transmission, and competition for food and oxygen.
The density of offspring was found to affect egg survival, and in some cases abandonment or cannibalism, many of these species.
"For example, in single energies, fathers were more likely to eat eggs in low oxygen conditions," Kellogg notes. "Such cases have led to the hypothesis that eating or abandoning offspring can be adapted to improve the overall survival of the offspring by reducing their density."
Parents and parents eat their offspring
Kellogg and his colleagues created a mathematical model to test the hypothesis.
"The model presented an imaginary person with a mutation to cannibal cannibalism or abandonment of offspring, to a population of animals laying generic eggs," explains lead author Dr. Mackenzie Davenport of the University of Tennessee.
As in previous group models, the gene for cannibalism spread throughout the population if it gave parents extra calories.
But for the first time in this model, they found that when infant mortality increases with egg density, both infant cannibalism and child abandonment help to increase body capacity.
"Under these conditions, the mutants were able to come out and replace the generic population," Davenport reports.
This was also the case when the cannibal parents received little or no energy to enjoy the extra food – or when abandoned offspring were allowed to die.
"Our findings show that cannibal cannibalism and abandonment of offspring can surprisingly act as forms of parental care by increasing the total survival of the offspring."
Live fast, young, be ready to cast
"The fitness advantage of child abandonment and infant cannibalism has also increased with the increase in adult mortality, especially in the case of infant cannibalism," said study author Prof. Michael Bonsel of the University of Oxford.
In other words: if you have fewer shots in reproduction, you will have to be cruel in defending your modesty. But if the death of the offspring depends on the density, why produce so many eggs in the first place?
"It is not always possible for parents to predict the environment that their offspring end up," explains Boncel. "Factors such as availability of food, availability of oxygen, presence of disease and anxiety may change unexpectedly, and in many fish and other animals, females deposit their eggs in male or female nests or territories so that optimum optimal density can not be predicted given that women Others may add eggs to the nest. "
"It's up to the empirists now to test these models in a variety of species," the authors conclude.
Should I eat the children? When to care, abandon, or eat your offspring
Boundaries of ecology and evolution, DOI: 10.3389 / fevo.2019.00113, https://www.frontiersin.org/articles/10.3389/fevo.2019.00113/full
Honey, I've Eat the Kids: The Sweet Side of Baby Cannibalism (2019, April 16)
April 16, 2019
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