[12] Because of its several tectonic origins, various faults scar the land and as a result the island is prone to earthquakes, including the deadly 2018 and 2021 quakes.

Evidence for this tectonic event lies with the extensive interconnected fault network found in the area, a volcanic seamount with its surrounding ridges, and an accretionary wedge.

[14] In the east, the traditional view of collisions of multiple micro-continental fragments sliced from New Guinea with an active volcanic margin in West Sulawesi at different times since the Early Miocene c. 20 Mya has recently been replaced by the hypothesis that extensional fragmentation has followed a single Miocene collision of West Sulawesi with the Sula Spur, the western end of an ancient folded belt of Variscan origin in the Late Paleozoic.

[citation needed] The past geological history has allowed for a large accumulation of carbonates which could lead to a higher potential of oil and gas occurrences.

[17] No earlier evidence of human occupation had at that point been found, but the island almost certainly formed part of the land bridge used for the settlement of Australia and New Guinea by at least 40,000 BC.

[24][25] A burial of a woman associated with the hunter-gatherer Toalean culture dating to 7,000 years ago has yielded DNA that has provided rare insight into early migrations in and through the region.

"[29] On 11 December 2019, a team of researchers led by Dr. Maxime Aubert announced the discovery of the oldest hunting scenes in prehistoric art in the world that is more than 44,000 years old from the limestone cave of Leang Bulu' Sipong 4.

Archaeologists determined the age of the depiction of hunting a pig and buffalo thanks to the calcite 'popcorn', different isotope levels of radioactive uranium and thorium.

[30][31][32] In March 2020, two small stone 'plaquettes' were found by Griffith University archaeologists in the Leang Bulu Bettue cave, dated to a time between 26,000 and 14,000 years ago.

[38][39][40][41] A bronze Amaravathi statue was discovered at Sikendeng, South Sulawesi near Karama river in 1921 which was dated to 2nd–7th century AD by Bosch (1933).

It seems that by the 14th century, polities in the island were connected in an archipelagic maritime trading network, centered in the Majapahit port in East Java.

In 1669, Admiral Speelman forced the ruler, Sultan Hasanuddin, to sign the Treaty of Bongaya, which handed control of trade to the Dutch East India Company.

The Dutch built a fort at Ujung Pandang, while Arung Palakka became the regional overlord and Bone the dominant kingdom.

In 1905, the entire island became part of the Dutch state colony of the Netherlands East Indies until Japanese occupation in the Second World War.

Scholars relate[citation needed] that their control swayed under Ternate and Makassar, but this might have been a decision by the Dutch to give their vassals a chance to govern a difficult group.

[51] In the late 19th century, the Sarasins journeyed through the Palu valley as part of a major initiative to bring the Kaili under Dutch rule.

Erskine Downs in the 1950s produced a summary of Kruyts and Andrianis work: "The religion of the Bare'e-Speaking Toradja of Central Celebes," which is invaluable for English-speaking researchers.

Christians are concentrated on the tip of the northern peninsula around the city of Manado, which is inhabited by the Minahasa, a predominantly Protestant people, and the northernmost Sangir and Talaud Islands.

Sulawesi is part of Wallacea, meaning that it has a mix of both Indomalayan and Australasian species that reached the island by crossing deep-water oceanic barriers.

Bunaken National Park, which protects a rich coral ecosystem, has been proposed as a UNESCO World Heritage Site.

[68] A Pleistocene faunal turnover is recognized, with the competitive displacement of several indigenous tarsiers by more recently arriving ones and of Celebochoerus by other medium-sized herbivores like the babirusa, anoa and Celebes warty pig.

While most of Sulawesi's mammals are placental and have Asian relatives, several species of cuscus, arboreal marsupials of Australasian origin, are also present (Ailurops ursinus and Strigocuscus celebensis, which are diurnal and nocturnal, respectively).

An international partnership of conservationists, donors, and local people have formed the Alliance for Tompotika Conservation,[71] in an effort to raise awareness and protect the nesting grounds of these birds on the central-eastern arm of the island.

The larger reptiles of Sulawesi are not endemic and include reticulated and Burmese pythons, the Pacific ground boa, king cobras, water monitors, sailfin lizards,[72] saltwater crocodiles[72][73] and green sea turtles.

An extinct giant tortoise, Megalochelys atlas, was formerly present, but disappeared by 840,000 years ago, possibly because of the arrival of Homo erectus.

[75][76] In addition to Nomorhamphus, the majority of Sulawesi's freshwater fish species are ricefishes, gobies (Glossogobius and Mugilogobius) and Telmatherinid sail-fin silversides.

[79] The last family is almost entirely restricted to Sulawesi, especially the Malili Lake system, consisting of Matano and Towuti, and the small Lontoa (Wawantoa), Mahalona and Masapi.

[84][85] Several of these species have become very popular in the aquarium hobby, and since most are restricted to a single lake system, they are potentially vulnerable to habitat loss and overexploitation.

The island also possesses one of the largest outcrops of serpentine soil in the world, which support an unusual and large community of specialized plant species.

Overall, the flora and fauna of this unique center of global biodiversity is very poorly documented and understood and remains critically threatened.