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Marcos Castro e Silva, PhD 🇧🇷

@macscastro.bsky.social

188 followers 381 following 35 posts

Postdoc fellow at the Globe Institute @ucph.bsky.social • Interested in how genomics can help us understand human history and evolution • he/him macscastro.github.io

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Marcos Castro e Silva, PhD 🇧🇷 @macscastro.bsky.social · 22/04/2026

We found evidence for at least 3 major dispersals into South America: 1) an early dispersal more than 12,000 years ago 2) a second one beginning ~9,000 years ago 3) a previously unrecognized third dispersal during the Late Holocene, starting at least 1,300 years ago

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Marcos Castro e Silva, PhD 🇧🇷 @macscastro.bsky.social · 22/04/2026

We found that the genetic structure of Indigenous peoples closely follows geography. Populations from the Andes, Amazon, Chaco, Southern Cone, Mesoamerica, and northern Mexico each form distinct genetic clusters. These patterns also reveal long-term regional continuity.

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Marcos Castro e Silva, PhD 🇧🇷 @macscastro.bsky.social · 22/04/2026

One striking result: more than a million genetic variants we found had never been reported before. Even though Indigenous Americans are often thought to have lower overall genetic diversity because of ancient bottlenecks, their genomes contain a huge amount of unique variation.

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Marcos Castro e Silva, PhD 🇧🇷 @macscastro.bsky.social · 22/04/2026

We generated 128 new high-coverage genomes from 45 Indigenous populations across 8 countries, representing 28 language families. We then combined them with published ancient and present-day genomes to build one of the most comprehensive genomic datasets for Indigenous Americans.

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