Genomic Signatures of Island Colonisation in Highly Diverse Primates.

Area of Science:

• Conservation genetics
• Evolutionary biology
• Primate genomics

Background:

• Understanding genetic diversity loss in small populations is vital for biodiversity conservation.
• Insular populations often experience lower genetic diversity and higher inbreeding than mainland counterparts.
• Comparative genomics of widespread species' insular vs. mainland populations can reveal consequences of population declines.

Purpose of the Study:

• To assess genome-wide diversity, inbreeding, genetic load, and adaptive variation in insular vs. mainland populations of three West African primate species.
• To investigate the genetic consequences of reduced population sizes and increased inbreeding in island populations.
• To determine if these island populations are at risk of extinction due to genetic factors.

Main Methods:

• Whole genome sequencing of spot-nosed monkeys (Cercopithecus petaurista), Campbell's monkeys (Cercopithecus campbelli), and green monkeys (Chlorocebus sabaeus).
• Comparative genomic analysis between insular populations from the Bijagós Archipelago and mainland populations.
• Assessment of genome-wide diversity, inbreeding coefficients, genetic load, and signatures of selection.

Main Results:

• Island populations consistently showed lower genome-wide diversity and higher inbreeding compared to mainland populations.
• Genetic drift appears to have increased realized genetic load by exposing previously masked deleterious variations.
• No evidence of accumulating deleterious variation was found, indicating these populations are not genetically endangered.
• Island populations may serve as reservoirs of mainland genetic diversity.

Conclusions:

• While insular primates in West Africa face genetic challenges like reduced diversity and higher inbreeding, they are not currently at risk from accumulating deleterious mutations.
• Conservation efforts should prioritize addressing immediate anthropogenic threats to these island populations.
• Safeguarding these populations is crucial to prevent further loss of valuable genetic diversity.