Animals in the wild, including primates and rodents, “tolerate and may even prefer” mating with their relatives, scientists say
- A team from Stockholm University summarized 139 studies with 88 species
- Biologists show that animals are tolerant and may even prefer to mate with their relatives
- They found that rodents in particular deal with what they call “kinship preference”.
Animals in the wild such as primates and rodents tolerate and may even prefer mating with their relatives, a new study shows.
Stockholm University researchers have compiled 139 experimental studies on 88 species spanning 40 years of research.
The team wanted to find out whether species avoid inbreeding, given a choice, or deliberately engage in it – something known as “kinship preference”.
Their results suggest that biologists should reconsider the popular belief that wild species deliberately avoid mating with their relatives.
Of the 88 species assessed by the researchers, five showed the strongest kinship preference, including the rhesus monkey (Macaca mulatta, picture)
TOP FIVE KIN PREFERENCES
Of the 88 species that were evaluated by the researchers, five showed the strongest kinship preference – a rodent, a primate, two fish, and a springtail species.
– The Littledale’s whistling rat (Parotomys littledalei)
– The African cichlid (Pelvicachomis taeniatus)
– The springtail (Orchesella cincta)
– The lake trout (Salvelinus namaychu)
– The rhesus monkey (Macaca mulatta)
“People assume that animals should avoid mating with a relative when they have the opportunity,” said study author Raïssa de Boer, a zoology researcher at Stockholm University.
“However, the theory of evolution tells us that animals should tolerate or even prefer mating with relatives in a wide range of conditions for more than four decades.
“We’re addressing the elephant in the inbreeding prevention studies room by breaking the popular belief that animals will avoid inbreeding whenever possible.”
Of the 88 species assessed by the researchers, five showed the preference for relatives the most – a rodent, a primate, two fish, and a springtail species (a hexapod that looks like a flea).
But in general, the top 10 species of rodents were dominated.
“Animals don’t seem to care whether their potential partner is a brother, sister, cousin or unrelated person when deciding who to mate with,” said study author Regina Vega Trejo of Stockholm University .
The researchers also found “consistent” evidence of a publication bias in favor of studies according to which the animals avoid mating with relatives.
The idea that animals avoid mating with relatives was the starting point for hundreds of scientific studies that have been conducted on many species.
However, the meta-analysis found little support for the widespread view that animals avoid mating with relatives.
A small part of the overall analysis also looked at avoiding inbreeding in humans, and the team compared the results to similar animal studies.
They related to studies asking if people should avoid inbreeding when presenting images of faces that have been digitally manipulated to make the faces look more or less related to the participants.
“Humans, like other animals, have no preference for unrelated potential partners when they base their decisions on only visual cues,” said John Fitzpatrick, associate professor of zoology at Stockholm University and lead author of the study.
“Obviously, however, this is a long way from the actual pairing.”
In the picture Orchesella cincta – a springtail species occurring in North America and Europe, which had a strong relationship preference
The study shows that animals rarely attempt to avoid mating with relatives, a finding that was consistent across a variety of conditions and experimental approaches. Wolves were among the species studied, although they showed neither a strong kinship preference (decision to mate with relatives) nor an “avoidance of relatives” (decision not to mate with relatives).
The results will have far-reaching implications for conservation biology as mate choice is increasingly used in conservation breeding programs
“A primary goal of conservation efforts is to preserve genetic diversity, and mate selection is generally expected to achieve this goal,” said Professor Fitzpatrick.
“Our results advise caution when using partner choice in conservation programs.”
The study was published in Nature Ecology and Evolution.
Zebras with spots and gold fur are observed through inbreeding in Africa
Zebras are known for their black and white stripes, but for several years scientists have found that some of the animals have spots, strange patterns, and even golden fur.
Such changes, usually caused by genetic mutations, are rarely seen in mammals, which has sparked a new study on what causes the change in zebras.
A team from the University of California at Las Angeles performed DNA tests on 140 zebras on the plains – including seven with strange fur patterns – from nine national parks in Africa.
The researchers found that isolated populations caused abnormal stripping as a result of inbreeding, due to habitat fragmentation by people taking over the land.
A lack of genetic diversity can lead to genetic defects, disease, and sterility that can ultimately lead to the extinction of simple zebras.
Zebras are known for their black and white stripes, but for several years scientists have found that some of the animals have spots, strange patterns, and even golden fur
Read more: Zebras with spots and gold fur are observed through inbreeding in Africa