The Philippines is a country of Southeast Asia, with its 7,107 islands strewn over the Western Pacific Ocean, approximately 13 N of the equator and 122 E of Greenwich. Its collective land area is about 300,000 sq. km, about the size of the state of Arizona. This island archipelago is one of the most megadiverse countries in the world, housing over 5% of the entire world’s flora in an area not even 1% of the world’s total. An estimated 10,000 to 11,000 species of plants are believed to occur in the Philippines and likely many more if the tropical forests were fully explored and documented. Over half of the named plants are endemic.
This high level of endemism is also present in the animals. Forty-four percent of its vertebrate species and almost 70% of its insects are also found nowhere else in the world Among the world’s 25 top biological hotspots the Philippines ranks second in the number of species per square kilometer, thus the endemic species are concentrated in exceptionally small areas Only 7% of its old growth closed-canopy forests remain from over 60% in 1945. With so many islands, the Philippines surpass Hawaii and the Galapagos in species biodiversity and endemism, and would be the perfect system to understand why it is a cauldron of evolution.
In fact, the Philippines has been described as tenfold more diverse than Galapagos. As predicted by Wilson and MacArthur’s theory of island biogeography, different island sizes, ages and distance from mainland Asia have influenced colonization, extinction, and diversification rates of Philippine biota. These island features coupled with their individual geological histories throughout the Cenozoic may hold the answer as to why the Philippines Is one of the world’s most biodiversity regions. The Ancient geological history of the Philippines archipelago.
As Australia drifted northward and began to collide with Asia, tectonic pressure caused parts of the Pacific seafloor to uplift, producing volcanoes that gave rise to the Philippine islands. Sometime in the mid-Oligocene, about, the Philippines was starting to take shape with the development of three major geological blocks. The first unit, which now comprise modern day Palawan and Mindoro and other smaller islands, rifted from the Asian continental shelf, south of the current location of Taiwan. At about the same time, hundreds of ilometers southeast of its present-day location, proto-Luzon, which began as a string of small volcanic islands developing beneath a shallow sea, was moving northwest. Further southeast of proto-Luzon, the islands of the Visayas and Mindanao were borne out of the continued subduction of the converging plates in the Pacific, and were also migrating northwest. Throughout the Cenozoic, these major geological units were approaching one another, but it was only in the Miocene that they began to emerge above sea level.
Mindoro was uplifted and large land areas were already exposed for the two other geological units. Starting in the Pliocene, Palawan emerged, while other smaller islands and peninsulas such as Bicol, Camiguin and Sibuyan, and the Sulu islands only surfaced much later The 7000+ islands of the Philippines had never been connected to any other Asian landmass, except for Palawan, which became contiguous with Borneo when sea level dropped repeatedly during the Pleistocene, accounting for Palawan’s biotic similarity to the former.
The isolation of the Philippines from the rest of Asia allowed it to develop its unique flora and fauna, thus explaining its staggering levels of endemism. Moreover, many species are not only endemic to the Philippines but unique to individual Philippine islands. Other islands, like Negros and Panay, share faunal species which surprisingly are different from those on other adjacent Visayan islands such as Leyte and Samar, whose fauna are, in turn, more similar to those of Mindanao. Masbate’s fauna are also more related to Negros and Panay’s than they are to the more proximal Luzon.
These patterns were observed in many vertebrates including birds, amphibians, mammals, reptiles and fishes. This theory is have similarity in Asiatic theory which suggest the Philippines is part of the Asia in ancient time because of the tectonic plate movement the Philippines is rifted of to mainland Asia, in this theory only Palawan, Mindoro and some of the island rifted of the Asia and the rest never connect in Asia because the Philippines came into existence after the eruptions of volcanoes beneath the ocean and the piling up of what they threw out, and this theory is said it as well.
That two theory according to archeologists and geologists, the most possible scientific explanations for our country’s origin which mean the collide of the two theory is gave answer, I believe this is the theory of origin of the Philippines.