Isthmus of Panama in the context of "Francisco Pizarro"

In biogeography, a land bridge is an isthmus or wider land connection between otherwise separate areas, over which animals and plants are able to cross and colonize new lands. A land bridge can be created by marine regression, in which sea levels fall, exposing shallow, previously submerged sections of continental shelf; or when new land is created by plate tectonics; or occasionally when the sea floor rises due to post-glacial rebound after an ice age.

Today the term South Seas, or South Sea, most commonly refers to the portion of the Pacific Ocean south of the equator. The term South Sea may also be used synonymously for Oceania, or even more narrowly for Polynesia or the Polynesian Triangle, an area bounded by the Hawaiian Islands, New Zealand and Easter Island. Pacific Islanders are commonly referred to as South Sea Islanders, particularly in Australia.

The term was coined as Mar de Sur, or "South Sea",  by Spanish conquistador Vasco Núñez de Balboa in 1513 as he it encountered on the southern coast of the Isthmus of Panama and it was applied to the entirety today's Pacific Ocean. In 1520, Ferdinand Magellan named the same ocean the Pacific Ocean, and over time Magellan's name became more well-known.

The San Blas Islands of Panama is an archipelago comprising approximately 365 islands and cays, of which 49 are inhabited. They lie off the north coast of the Isthmus of Panama, east of the Panama Canal. A part of the comarca (district) Guna Yala along the Caribbean coast of Panama, it is home to the Kuna people.

San Blas and its surrounding area is a haven for ecotourism because of its pristine environs. The area is also popular for sailing, as it is known for its beauty and lack of hurricanes. Notable locations in the Archipelago are the main capital Gaigirgordub, the densely crowded island village of Carti Sugtupu, and the two keys, Cayos Limones, and Cayos Holandeses, both renowned for their clear waters.

The Central American Seaway (also known as the Panamanic Seaway, Inter-American Seaway and Proto-Caribbean Seaway) was a prehistoric body of water that once connected the Pacific Ocean to the Atlantic Ocean, separating North America from South America. It formed during the Jurassic (200–154 Ma) during the initial breakup of the supercontinent Pangaea into Laurasia and Gondwana, forming a mediterranean sea between the Panthalassia and Tethys Ocean, and finally closed when the Isthmus of Panama was formed by volcanic activity in the late Pliocene (2.76–2.54 Ma). The modern-day remnants of the seaway are the Gulf of Mexico, Caribbean Sea and the Central Atlantic region around the Sargasso Sea.

The closure of the Central American Seaway had tremendous effects on oceanic circulation and the biogeography of the adjacent seas, isolating many species and triggering speciation and diversification of tropical and sub-tropical marine fauna. The inflow of nutrient-rich water of deep Pacific origin into the Caribbean was blocked and so local species had to adapt to an environment of lower productivity. It had an even larger impact on terrestrial life. The seaway had isolated South America for much of the Cenozoic, which allowed the evolution of a wholly unique diverse mammalian fauna there. When it closed, a faunal exchange with North America ensued and led to the extinction of many of the native South American forms.

The Great American Biotic Interchange (commonly abbreviated as GABI), also known as the Great American Interchange and the Great American Faunal Interchange, was an important late Cenozoic paleozoogeographic biotic interchange event in which land and freshwater fauna migrated from North America to South America via Central America and vice versa, as the volcanic Isthmus of Panama rose up from the sea floor, forming a land bridge between the previously separated continents. Although earlier dispersals had occurred, probably over water, the migration accelerated dramatically about 2.7 million years (Ma) ago during the Piacenzian age. It resulted from the joining of the Neotropic (roughly South American) and Nearctic (roughly North American) biogeographic realms definitively to form the Americas. The interchange is visible from observation of both biostratigraphy and nature (neontology). Its most dramatic effect is on the zoogeography of mammals, but it also gave an opportunity for reptiles, amphibians, arthropods, weak-flying or flightless birds, and even freshwater fish to migrate. Coastal and marine biota were affected in the opposite manner; the formation of the Central American Isthmus caused what has been termed the Great American Schism, with significant diversification and extinction occurring as a result of the isolation of the Caribbean from the Pacific.

The occurrence of the interchange was first discussed in 1876 by the "father of biogeography", Alfred Russel Wallace. Wallace had spent five years exploring and collecting specimens in the Amazon basin. Others who made significant contributions to understanding the event in the century that followed include Florentino Ameghino, W. D. Matthew, W. B. Scott, Bryan Patterson, George Gaylord Simpson and S. David Webb. The Pliocene timing of the formation of the connection between North and South America was discussed in 1910 by Henry Fairfield Osborn.

Conquistadors (/kɒnˈk(w)ɪstədɔːrz/, US also /-ˈkiːs-, kɒŋˈ-/) or conquistadores (Spanish: [koŋkistaˈðoɾes]; Portuguese: [kõkiʃtɐˈðoɾɨʃ, kõkistɐˈdoɾis]; lit. 'conquerors') were Spanish and Portuguese colonizers who explored, traded with and conquered parts of the Americas, Africa, Asia, and Oceania during the Age of Discovery. Sailing beyond the Iberian Peninsula, they established numerous colonies and trade routes, and brought much of the New World under the dominion of Spain and Portugal.

After Christopher Columbus's arrival in the West Indies in 1492, the Spanish, usually led by hidalgos from the west and south of Spain, began building a colonial empire in the Caribbean using colonies such as Santo Domingo, Cuba, and Puerto Rico as their main bases. From 1519 to 1521, Hernán Cortés led the Spanish conquest of the Aztec Empire, ruled by Moctezuma II. From the territories of the Aztec Empire, conquistadors expanded Spanish rule to northern Central America and parts of what is now the southern and western United States, and from Mexico sailing the Pacific Ocean to the Spanish East Indies. Other Spanish conquistadors took over the Inca Empire after crossing the Isthmus of Panama and sailing the Pacific to northern Peru. From 1532 to 1572, Francisco Pizarro succeeded in subduing this empire in a manner similar to Cortés. Subsequently, Spanish conquistadores used Peru as a base for conquering much of Ecuador and Chile. Central Colombia, home of the Muisca, was conquered by licentiate Gonzalo Jiménez de Quesada, and its northern regions were explored by Rodrigo de Bastidas, Alonso de Ojeda, Juan de la Cosa, Pedro de Heredia and others. For southwestern Colombia, Bolivia, and Argentina, Spanish conquistadores from Peru combined parties with other conquistadors arriving more directly from the Caribbean and Río de la Plata-Paraguay respectively. These conquests founded the basis for modern Hispanic America and the Hispanosphere.

The Neogene (/ˈniː.ədʒiːn/ NEE-ə-jeen,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period 23.04 Ma (million years ago) to the beginning of the present Quaternary Period 2.58 Ma. It is the second period of the Cenozoic and the eleventh period of the Phanerozoic. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene. Some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes (1815–1868). The earlier term Tertiary Period was used to define the span of time now covered by Paleogene and Neogene and, despite no longer being recognized as a formal stratigraphic term, "Tertiary" still sometimes remains in informal use.

During this period, mammals and birds continued to evolve into modern forms, while other groups of life remained relatively unchanged. The first humans (Homo habilis) appeared in Africa near the end of the period. Some continental movements took place, the most significant event being the connection of North and South America at the Isthmus of Panama, late in the Pliocene. This cut off the warm ocean currents from the Pacific to the Atlantic Ocean, leaving only the Gulf Stream to transfer heat to the Arctic Ocean. The global climate cooled considerably throughout the Neogene, culminating in a series of continental glaciations in the Quaternary Period that followed.

Vasco Núñez de Balboa (Spanish pronunciation: [ˈbasko ˈnuɲeθ ðe βalˈβo.a]; c. 1475 – around January 12–21, 1519) was a Spanish explorer, governor, conquistador, and a pirate. He is best known for being the first European to discover the Pacific Ocean while crossing the Isthmus of Panama in 1513.

He traveled to the New World in 1500 and, after some exploration, settled on the island of Hispaniola. He founded the settlement of Santa María la Antigua del Darién in present-day Colombia in 1510, which was the first permanent European settlement on the mainland of the Americas (a settlement by Alonso de Ojeda the previous year at San Sebastián de Urabá had already been abandoned).