Using next-generation sequencing methods to isolate and characterize 24 simple sequence repeat loci in mandrills (Mandrillus sphinx)

Harté

Poirotte

et al. 2019

Preprint

Animal faces convey important information such as individual health status1 or identity2,3. Human and nonhuman primates rely on highly heritable facial traits4,5 to recognize their kin6–8. However, whether these facial traits have evolved for this specific function of kin recognition remains unknown. We present the first unambiguous evidence that inter-individual facial similarity has been selected to signal kinship using a state-of-the-art artificial intelligence approach based on deep neural networks and long-term data on a natural population of nonhuman primates. The typical matrilineal society of mandrills, is characterized by an extreme male’s reproductive skew with one male generally siring the large majority of offspring born into the different matrilines each year9. Philopatric females are raised and live throughout their lives with familiar maternal half-sisters (MHS) but because of male’s reproductive monopolization, they also live with unfamiliar paternal half-sisters (PHS). Because kin selection predicts differentiated interactions with kin rather than nonkin10 and that PHS largely outnumber MHS in a mandrills’ social group, natural selection should favour mechanisms to recognize PHS. Here, we first show that PHS socially interact with each other as much as MHS do, both more than nonkin. Second, using artificial intelligence trained to recognize individual mandrills from a database of 16k portrait pictures, we demonstrate that facial similarity increases with genetic relatedness. However, PHS resemble more to each other than MHS do, despite both kin categories sharing similar degrees of genetic relatedness. We propose genomic imprinting as a plausible genetic mechanism to explain paternally-derived facial similarity among PHS selected to improve kin recognition. This study further highlights the potential of artificial intelligence to study evolutionary mechanisms driving variation between phenotypes.

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Same father, same face: deep-learning reveals paternally-derived signalling of kinship in a wild primate

Harté

Poirotte

et al. 2019

Preprint

“…) to 36 (natural population; Benoit et al. ) primer pairs. Paternity analyses were performed using Cervus 3.0 software using previously described procedures (Charpentier et al.…”

Section: Methodsmentioning

confidence: 99%

“…Individuals from the two study populations were regularly captured using blowpipe intramuscular injections of anesthetics Galbany et al 2014), and blood samples were collected on every occasion. DNA extractions from the buffy coat (white cells) were performed using QIAamp DNA Blood Mini Kits (Hilden, Germany), and microsatellite genotyping was carried out using 12 (captive population; Charpentier et al 2005) to 36 (natural population; Benoit et al 2014) primer pairs. Paternity analyses were performed using Cervus 3.0 software using previously described procedures .…”

Section: Determination Of Relatedness and Familiarity Between Animalsmentioning

confidence: 99%

Visual Discrimination of Kin in Mandrills

Harté²,

Ngoubangoye

et al. 2017

Ethology

Self Cite

Phenotype matching, a learning mechanism that evolved based on phenotypic cues shared among relatives, may provide animals with the ability to recognize unfamiliar kin. The generalization of this mechanism across animal species is debated, however, because appropriate tests are difficult to design due to possible confounding effects of familiarity. Hence, only a few studies have examined evidence for the existence of such a mechanism in natural populations. Here, we tested the phenotype matching hypothesis based on visual cues in a semi‐free‐ranging population of mandrills (Mandrillus sphinx) that contains individuals related to different degrees and where familiarity is controlled for. Using an experimental design based on the presentation of photographs, we show that mandrills discriminate unfamiliar relatives using facial cues alone. Our results build on earlier studies, showing that primates use phenotype matching to recognize and subsequently discriminate unfamiliar kin. We suggest that facial features along with other visual and non‐visual cues provide a proximate mechanism for kin selection to operate.

“…Sixty-five individuals were trapped at least once using blowpipe intramuscular injections of anaesthetics [26,27] allowing the collection of blood samples. DNA extractions from the buffy coat were performed using QIAamp DNA Blood Mini Kits (Hilden, Germany) and microsatellite genotyping was carried out using 12-36 primer pairs [26][27][28]. Paternities were determined using Cervus 3.0 software using previously described procedures [28].…”

Section: (D) Genetic Analysesmentioning

confidence: 99%

Unconditional care from close maternal kin in the face of parasites

Poirotte

2020

Biol. Lett.

Self Cite

Several species mitigate relationships according to their conspecifics' parasite status. Yet, this defence strategy comes with the costs of depriving individuals from valuable social bonds. Animals therefore face a trade-off between the costs of pathogen exposure and the benefits of social relationships. According to the models of social evolution, social bonds are highly kin-biased. However, whether kinship mitigates social avoidance of contagious individuals has never been tested so far. Here, we build on previous research to demonstrate that mandrills ( Mandrillus sphinx ) modulate social avoidance of contagious individuals according to kinship: individuals do not avoid grooming their close maternal kin when contagious (parasitized with oro-faecally transmitted protozoa), although they do for more distant or non-kin. While individuals' parasite status has seldom been considered as a trait impacting social relationships in animals, this study goes a step beyond by showing that kinship balances the effect of health status on social behaviour in a non-human primate.