Refuting Creationism - The 40-Million-Year History of Biodiversity in The Indo-Australian Archipelago

Vibrant marine life in the Coral Triangle region of Sabah, Malaysia, showcasing the area's remarkable biodiversity.

Photo credit: David M. Baker.

Stunning coral formations captured in the waters of the Coral Triangle, Sabah, Malaysia.

Photo credit: David M. Baker.

HKU Ecologists Reconstruct the History of Biodiversity in the Indo-Australian Archipelago and its Rise as a Hotspot - Press Releases - Media - HKU

If you're a creationist fraud trying to fool more scientifically-illiterate simpletons into joining your cult and giving you money so you don't need to earn an honest living, the last thing you need is this constant deluge of evidence refuting your claims that Earth is only a few thousand years old and everything on it was magically created as it is today.

And yet here we have yet another refutation in the form of a research paper detailing the 20-million-year history of one of the most biodiverse places on Earth - the 'Indo-Australian Archipelago', also called 'The Coral Triangle'.

The Indo-Australian Archipelago has been described as a biodiversity hot-spot because it contains so many examples of radiating evolution over the last 20 million years.

Tell me about the 'Indo-Australian Archipelago' and its role in biodiversity, please. The Indo-Australian Archipelago, also known as the Indo-Malay Archipelago or the Maritime Southeast Asia, is a vast region of Southeast Asia that includes thousands of islands scattered across the Indian and Pacific Oceans. This region encompasses countries like Indonesia, Malaysia, the Philippines, Timor-Leste, Brunei, and Papua New Guinea. The archipelago plays a significant role in global biodiversity due to its unique geographical and climatic features, making it one of the most biodiverse regions on Earth. Here's an overview of its role in biodiversity:

Geographic and Environmental Factors

1. Isolation and Endemism: The numerous islands have been isolated from each other and from mainland Asia for millions of years, leading to high levels of endemism. Many species found in this region are unique to specific islands or island groups.
2. Varied Habitats: The archipelago features a wide range of habitats including rainforests, mangroves, coral reefs, mountains, and savannas. This diversity of habitats supports a wide array of flora and fauna.
3. Coral Triangle: The region lies within the Coral Triangle, which is the global center of marine biodiversity. It has the highest diversity of coral and reef fish species in the world.

Biodiversity Highlights

1. Flora: The Indo-Australian Archipelago is home to over 25,000 plant species. The rainforests of Borneo and Sumatra are particularly rich in biodiversity, hosting numerous species of dipterocarps, orchids, and the world's largest flower, Rafflesia arnoldii.
2. Fauna:
   • Mammals: The region is home to a variety of mammals, including unique species such as the orangutan, Sumatran tiger, Javan rhinoceros, and the Komodo dragon.
   • Birds: Over 1,600 bird species inhabit the archipelago, including the critically endangered Philippine eagle and the stunning birds-of-paradise found in Papua New Guinea.
   • Reptiles and Amphibians: The region supports a diverse array of reptiles and amphibians, including many endemic species of frogs, lizards, and snakes.
   • Marine Life: The Coral Triangle within this region hosts over 600 species of reef-building corals and more than 2,000 species of reef fish. It is also a vital habitat for sea turtles and various marine mammals.

Conservation Challenges

1. Deforestation: Rapid deforestation due to logging, agriculture, and palm oil plantations threatens terrestrial biodiversity. The loss of habitat is a significant threat to many endemic species.
2. Overfishing and Coral Reef Degradation: Overfishing, destructive fishing practices, and climate change are major threats to marine biodiversity. Coral bleaching and reef destruction impact the marine ecosystem's health.
3. Climate Change: Rising temperatures and changing weather patterns affect both terrestrial and marine ecosystems, posing risks to species that are sensitive to environmental changes.
4. Pollution: Pollution, including plastic waste and chemical runoff, harms wildlife and ecosystems both on land and in the sea.

Conservation Efforts

1. Protected Areas: Establishing and managing protected areas, such as national parks and marine reserves, is crucial for conserving biodiversity. Examples include the Tubbataha Reefs Natural Park in the Philippines and the Lorentz National Park in Papua.
2. Sustainable Practices: Promoting sustainable agricultural, forestry, and fishing practices helps reduce environmental impact and preserve ecosystems.
3. Community Engagement: Involving local communities in conservation efforts is essential for ensuring sustainable management of natural resources.
4. Research and Monitoring: Ongoing scientific research and monitoring are vital for understanding biodiversity trends and implementing effective conservation strategies.

The Indo-Australian Archipelago is a crucial region for global biodiversity, harboring a rich array of species and ecosystems. However, it faces significant conservation challenges that require concerted efforts from governments, organizations, and local communities to protect its natural heritage.

The study was co-led by Dr Skye Yunshu TIAN from the University of Bonn, who conducted the major part of the research at The University of Hong Kong (HKU), along with Professor Moriaki YASUHARA from HKU School of Biological Sciences, the Swire Institute of Marine Science (SWIMS) and Institute for Climate and Carbon Neutrality (ICCN), as well as Dr Fabien L. CONDAMINE of Centre National de la Recherche Scientifique (CNRS), has now been published in the journal Nature.

It is described in a University of Hong Kong News release:

HKU Ecologists Reconstruct the History of Biodiversity in the Indo-Australian Archipelago and its Rise as a Hotspot

The Coral Triangle, also known as the Indo-Australian Archipelago, is renowned for having the greatest marine biodiversity on our planet. Despite its importance, the detailed evolutionary history of this biodiversity hotspot has remained largely a mystery. An international research team has now shed light on this history, reconstructing how biodiversity in the region has developed over the past 40 million years.

The researchers began their investigation by examining sediment samples from the Indo-Australian Archipelago in the laboratory and identifying the fossils they contained.

We wanted to understand how the marine biodiversity of the Indo-Australian Archipelago evolved and persisted, and what factors were responsible for the disproportionately high diversity in the tropics.

Skye Yunshu Tian, co-lead author
School of Biological Sciences
Area of Ecology and Biodiversity
The University of Hong Kong, Hong Kong, Hong Kong SAR.

Their findings revealed that the archipelago had shown an increase in diversification since the early Miocene, around 20 million years ago. Approximately 2.6 million years ago, the number of species approached a plateau. Interestingly, there were no major extinction events during the entire study period.

The increase in diversity was primarily driven by the habitat factor, as tectonic collisions (movements of Earth’s plates) in Southeast Asia created extensive areas of shallow marine habitats.

Skye Yunshu Tian.

Around 14 million years ago, the region’s thermal stress, or excessive heat, began to moderate.

This moderation was crucial for the development of the hotspot. During the Eocene (56 to 34 million years ago), excessively high tropical temperatures in warm climate zones hindered the increase in diversity. The cooling after that allowed for a more favourable environment for biodiversity to flourish.

Our palaeobiological results suggest that we could quickly lose the fantastic diversity of the tropical hotspot if the ongoing anthropogenic warming intensifies.

.

Skye Yunshu Tian.

However, this rich biodiversity could be at risk.

This reconstruction of the long-term history of the Coral Triangle diversity hotspot enables us to better understand how diversity hotspot moved from 'Tethys (ancient Mediterranean region)' region to the present place of the Coral Triangle and developed there. These are what we didn't know too clearly before. And also our results tell us why Coral Triangle diversity is much higher than that of the Caribbean Sea, that is probably because the Coral Triangle didn't experience large extinction event by luck.

Professor Moriaki Yasuhara, co-lead author.
School of Biological Sciences
Area of Ecology and Biodiversity
The University of Hong Kong, Hong Kong, Hong Kong SAR.

About the Journal Paper: Skye Yunshu Tian, Moriaki Yasuhara, Fabien L. Condamine, Huai-Hsuan M. Huang, Allan Gil S. Fernando, Yolanda M. Aguilar, Hita Pandita, Toshiaki Irizuki, Hokuto Iwatani, Caren P. Shin, Willem Renema & Tomoki Kase: Cenozoic history of the tropical marine biodiversity hotspot, Nature. The Journal Paper can be accessed from here: https://www.nature.com/articles/s41586-024-07617-4

Abstract
The region with the highest marine biodiversity on our planet is known as the Coral Triangle or Indo-Australian Archipelago (IAA)^1,2. Its enormous biodiversity has long attracted the interest of biologists; however, the detailed evolutionary history of the IAA biodiversity hotspot remains poorly understood³. Here we present a high-resolution reconstruction of the Cenozoic diversity history of the IAA by inferring speciation–extinction dynamics using a comprehensive fossil dataset. We found that the IAA has exhibited a unidirectional diversification trend since about 25 million years ago, following a roughly logistic increase until a diversity plateau beginning about 2.6 million years ago. The growth of diversity was primarily controlled by diversity dependency and habitat size, and also facilitated by the alleviation of thermal stress after 13.9 million years ago. Distinct net diversification peaks were recorded at about 25, 20, 16, 12 and 5 million years ago, which were probably related to major tectonic events in addition to climate transitions. Key biogeographic processes had far-reaching effects on the IAA diversity as shown by the long-term waning of the Tethyan descendants versus the waxing of cosmopolitan and IAA taxa. Finally, it seems that the absence of major extinctions and the Cenozoic cooling have been essential in making the IAA the richest marine biodiversity hotspot on Earth.

Main
It is unclear how the global centre of marine biodiversity, the IAA, has developed, and why its biodiversity is disproportionally high compared to that of other tropical regions. These are key uncertainties in organismal biology. We have gradually gained a better understanding of global-scale diversity dynamics throughout the Cenozoic^4,5, revealing complex waxing and waning of diversity related to climatic and other environmental changes. However, regionally resolved Cenozoic diversity trends remain poorly understood owing to the scarcity of historical data and their compilation. This is particularly true for the tropics in deeper time, making the origins of high biodiversity an enigma^6,7,8. The current knowledge of the fossil record suggests that the locations of peak diversity (that is, biodiversity hotspots) shifted throughout the Cenozoic from the western Tethys during the Eocene to the Arabian Peninsula during the late Eocene–Oligocene, before being established at the current location of the IAA in Southeast Asia in the early Miocene: the process known as the hopping hotspots mode^l3,9. Plate tectonics is postulated to be the ultimate driver of this process by regulating the broad-scale availability and configuration of shallow-marine habitats with successive continent collisions⁹. Each hop of the biodiversity hotspots from the ancient location to the new one was probably underpinned by considerable speciation and extinction events, but also could be associated with the palaeobiogeographic shifts of some component taxa tracking suitable habitats³. However, the detailed Cenozoic history of the IAA hotspot remains elusive as explicated below. Better understanding the deep-time origin, evolution and maintenance of this most diverse place in the marine realm is crucial for macroevolutionary and macroecological studies and provides a solid theoretical framework for conservation efforts.

As one of the most conspicuous biogeographic and biodiversity patterns today, the IAA hotspot is characterized by an exceptional concentration of coastal benthic species, whereas pelagic groups show widespread distributions without a distinguished centre of diversity^2,10. Historical evidence from benthic taxonomic groups has advanced our understanding of tropical diversification yet suffers from various limitations. Recent molecular studies on corals and reef fishes revealed their biogeographic and evolutionary history to build the IAA hotspot, suggesting that it was a centre of species accumulation and origin at different intervals of the Cenozoic^11,12. However, these phylogeny-based models are subject to uncertainties in the case of incomplete sampling and undocumented extinctions. They also are not geographically defined to quantify a clear scenario of regional diversity changes in the IAA. In addition to molecular phylogeny evidence, previous palaeontological studies collectively indicate a compatible trend of increased IAA species richness at a coarse spatiotemporal resolution, which was dominated by immigration into the IAA in the Eocene–Oligocene and proliferation inside the IAA in the Oligocene–recent^6,9,13,14,15. However, difficulties in reconstructing a more detailed IAA history for benthic fossil groups include: a lack of sufficient fossil data or data synthesis for molluscs and bryozoans^8,15; a small species pool despite a good fossil record for larger benthic foraminifera⁶; and uncertainties in species-level identification for fossil corals⁷. Another critical, yet often overlooked, limitation is that our current knowledge of the marine hotspot is severely biased towards (sub)tropical reef-associated groups (mostly corals and reef fishes), even though the IAA peak in species richness is a common feature shared by many shallow-marine lineages regardless of reef affiliation¹⁰. By relying on reef taxa as the sole descriptor of the IAA hotspot, the strong correlation of their diversity patterns with reef habitat may mask the effects of other putative primary drivers on macroevolutionary and macroecological dynamics. Overall, Ostracoda (Arthropoda: Crustacea; known as seed shrimps) is one of the few benthic microfossil organisms that has left a rich fossil record within and beyond reef ecosystems for quantitative analysis¹⁶. Their high species diversity and robust taxonomy are two other major advantages¹⁶. Benthic ostracods show a normal latitudinal diversity gradient¹⁷ and depth diversity gradient¹⁸. They also exhibit a similar biogeographic distribution with other invertebrates¹⁹. Thus, instead of being a contrarian, ostracods are regarded as a normal benthic taxon that tends to follow standard ecological patterns¹⁷. In addition, small (<0.5 mm) benthic metazoan invertebrates account for most (more than two-thirds of) marine biodiversity^17,20, and the ostracod is probably the best fossil representative for this group in terms of general biotic response^13,16. These features make ostracods a very useful proxy for broad marine benthic biodiversity to investigate the ancient history of hotspots before the timescale of modern observations^13,16.

Here we used ostracods as a model proxy to assemble the first comprehensive Cenozoic fossil dataset for the IAA hotspot. Applying a birth–death model that incorporates the preservation process and mitigates bias in the fossil record, we first inferred a detailed regional diversity trajectory by explicitly estimating speciation and extinction rates. Given the regional scope of this study, speciation here corresponds to the first appearance of every species in the IAA to construct the emerging hotspot. The same rationale applies to extinction, which is defined as the final extirpation of any species from the IAA instead of global extinction. We then correlated the IAA’s macroevolutionary dynamics with a set of biotic and abiotic parameters to assess the potential biodiversity drivers. Finally, we placed the evolution of the IAA hotspot in a biogeographic context to explore how key biogeographic processes (that is, migration and origination of the Tethyan, cosmopolitan and endemic IAA fauna) altered long-term diversification.

Extended Data Fig. 1: Map of the Indo-Australian Archipelago showing sampling location, with a magnification of the Philippine islands.

The name of each sampling island is labelled in red.

Tian, S.Y., Yasuhara, M., Condamine, F.L. et al.
Cenozoic history of the tropical marine biodiversity hotspot. Nature (2024). https://doi.org/10.1038/s41586-024-07617-4

Copyright: © 2024 The authors.
Published by Springer Nature Ltd. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)

Interestingly, and no doubt to the annoyance of creationists frauds, the authors suggest that plate tectonics was this most important driver of biodiversity "by regulating the broad-scale availability and configuration of shallow-marine habitats with successive continent collision". Plate tectonics occurs over a very long time and certainly takes far longer than the 10,000 years that creationists believe Earth has been around. Then there is the clear acceptance by the biologists that biodiversity evolves according to environmental change which is the underlying driver of biological change, just as Darwin and Wallace explained.

There is absolutely no hint that the scientists found the TOE inadequate for explaining the observations and so were adopting supernatural magic by unproven entities who have never been witnessed doing anything, as a more scientific explanation than the current TOE.

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