How did lemurs colonize and evolve on Madagascar?

Lemurs are wet-nosed primates that are endemic to Madagascar, having evolved independently from monkeys and apes after an ancestral population reached the island. Scientific estimates for when ancestral lemurs colonized Madagascar via rafting events range widely from 40 to 65 million years ago. Isolated on the island, they underwent extensive independent evolution and diversification, filling numerous ecological niches.

What we know

• Lemurs are thought to have colonized Madagascar from Africa through rafting on floating mats of vegetation. [3, 5]
• Fossil evidence and nuclear DNA tests suggest lemurs arrived in Madagascar between 40 and 52 million years ago, while other DNA comparisons suggest a date range of 62 to 65 million years ago. [5] · medium confidence
• Having evolved independently on Madagascar for at least 40 million years, lemurs diversified to fill ecological niches normally occupied by other mammal types. [5]
• The timing and number of hypothesized colonizations have traditionally depended on the phylogenetic affinities of the aye-aye. [5] · medium confidence

Still open

• Sources disagree on the exact colonization date of lemurs, with estimates split between 40 to 52 million years ago and 62 to 65 million years ago.
• It remains uncertain whether terrestrial mammals colonized Madagascar via four or five separate rafting events.

Where to go next

• the bigger pictureWhat are the characteristics of strepsirrhine primates?
• a case in pointHow do aye-ayes use percussive foraging?
• whenWhen did humans first arrive on Madagascar?
• compared withHow do lorises and galagos relate to lemurs?
• how we knowWhat evidence supports the oceanic rafting hypothesis?
• an unexpected connectionHow does an endangered primate mimic a North American bird?The aye-aye fills the ecological niche of a woodpecker by tapping on wood and using a specialized long finger to extract grubs.

Sources

• [1]Lemuroidea (Wikidata Q1192405) · CC0 1.0
• [2]Lemur · CC BY-SA 4.0
• [3]List of mammals of Madagascar · CC BY-SA 4.0
• [4]Aye-aye · CC BY-SA 4.0
• [5]Evolution of lemurs · CC BY-SA 4.0