Isthmian America (28,577 to 7,822 BCE) Upper Pleistocene II — Deglaciation, Lagoon Growth, First Littoral Camps

Geographic & Environmental Context

Isthmian America includes Costa Rica, Panama, Darién (Panama–Colombia), San Andrés Archipelago, Galápagos Islands, and the Ecuadorian Capelands (Cabos Manglares, San Francisco, Pasado, San Lorenzo, Punta Santa Elena; Manta; western Esmeraldas, Manabí, Guayas, Santa Elena).

Anchors: Panama isthmus and Azuero; Darién–Chocó rainforests; Costa Rica Central Valley and Nicoya; San Andrés banks; Galápagos volcanic outliers; Manta–Santa Elena capes and lagoons.

Climate & Environmental Shifts

• Bølling–Allerød: wetter/warmer; forests expanded; lagoons formed.

• Younger Dryas: brief cool/dry; reef reliance spikes.

• Early Holocene: stable warmth, predictable rains.

Subsistence & Settlement

• Darién–Chocó and Nicoya/Azuero: seasonal shell-midden camps; fish, turtle, mangrove crabs; inland deer/peccary.

• Ecuadorian Capes (Manta–Santa Elena): surf-facing coves supported rich fisheries.

• San Andrés: occasional fishing stops; Galápagos: still uninhabited.

Technology & Material Culture

• Microliths; bone gorges/harpoons; net sinkers; early dugouts/rafting regionally.

Movement & Interaction Corridors

• Manta–Santa Elena ⇄ Nicoya/Azuero ⇄ Darién canoe hops; Caribbean San Andrés on long-haul spearing circuits.

Cultural & Symbolic Expressions

• Shell-heap feasts; beadwork; ritual hearths near capes/springs.

Adaptation & Resilience

• Diet breadth + reef “fallback foods” buffered Younger Dryas reversals.

Transition

• Early Holocene hydrology enables semi-sedentary rounds at lagoons and springheads.