Bizarre new fossils shed light on ancient plankton | News | University of Leicester
A scientist at the University of Leicester, UK, has discovered a new type of fossil, that lived half a billion years ago in the Cambrian Era. It resembles an algae but shows evidence of the beginnings of colonial existence as groups of cells joined together to form larger masses.
It was part of the Cambrian biota which evolved at a time of increasing competition between predatory and prey species, after multicellular life had evolved motility and the ability to hunt and consume other life forms, so exterminating the Ediacaran biota that preceded it.
Evolving the ability to group together into larger masses could have happened because doing so made it harder for a predator to consume the algae-like organisms.
In their obsessive search for something to discredit the Theory of Evolution, creationists often abandon one or more of their basic dogmas, confident that their target dupes won't realise they don’t have a coherent set of ideas with which to counter the vast body of science that established the TOE beyond a shadow of doubt.
This cavalier approach to truth also demonstrates the truism that there is no truth agenda in creationism; it’s all about recruiting more people into the cult in the childish belief that a fantasy becomes more and more true, as more and more people are fooled into believing it - a childish way of seeking safety in numbers.
A classic example of this is the absurd claim that the so-called 'Cambrian Explosion', which actually lasted several million years, was a literal explosion of life forms that arose overnight without ancestors. They believe this shows the work or a creator and simultaneously refutes the idea of common origins and the evolution of multicellular life from single-celled organisms.
And of course, it abandons the notion of a 10,000-year-old Earth and the mythical account in Genesis of how and when life on Earth was created, in which there is no mention of the Cambrian biota or anything resembling it.
First, a little background to the era in which these newly-discovered organisms lived:
Tell me all about the so-called 'Cambrian Explosion'. The Cambrian Explosion is a pivotal event in Earth's history that occurred approximately 541 million years ago during the Cambrian period of the Paleozoic era. It was a geological period lasting around 20 million years, but the most significant diversification of life happened over a relatively short span, possibly within just a few million years. The Cambrian Explosion is characterized by the sudden and rapid appearance of a wide variety of complex, multicellular life forms in the fossil record. Here are some key aspects of the Cambrian Explosion:This led to a series of arms races in which both defensive and offensive structures evolved, such as shells, hard jaws, exoskeletons, and limbs. It was during this period that simple eyes evolved to detect movement of both predator and prey and to find shelter in dark areas.The exact causes of the Cambrian Explosion are still a topic of debate among scientists. It is likely that a combination of environmental changes, genetic innovations, and ecological interactions played a role in driving this extraordinary event. The Cambrian Explosion is a subject of great interest in the study of evolutionary biology, as it provides insights into the processes that led to the development of the diverse life forms we see on Earth today.
- Sudden Diversification: Prior to the Cambrian Explosion, life on Earth was predominantly microbial and simple, consisting of single-celled organisms and some primitive multicellular life. During the Cambrian Explosion, there was a sudden and dramatic increase in the diversity and complexity of life forms.
- Fossil Evidence: The Cambrian Explosion is well-documented in the fossil record, with many new and unique body plans and species appearing during this time. Fossils from the Cambrian period reveal a profusion of arthropods, mollusks, annelids, and other early animal groups.
- Evolution of Hard Parts: One of the key features of the Cambrian Explosion was the development of hard parts such as shells, exoskeletons, and spines. These hard parts provided support and protection for early animals, allowing them to explore new ecological niches.
- Evolutionary Innovation: The Cambrian Explosion marked the evolution of various important features in animals, including sensory organs, complex eyes, appendages for locomotion and feeding, and different modes of mobility. This period saw the emergence of the first chordates, which are the ancestors of vertebrates.
- Environmental Factors: Several factors are thought to have contributed to the Cambrian Explosion. One of the most important was a significant increase in the levels of oxygen in the Earth's atmosphere and oceans. Oxygen is essential for the development of larger, more active organisms. Additionally, changes in sea chemistry, temperature, and the availability of nutrients likely played a role.
- Ecological Niches: The diversification of life during the Cambrian Explosion led to the occupation of various ecological niches. New predators and prey relationships formed, and the development of hard parts provided an arms race between predators and prey, driving further diversification.
- The Burgess Shale: The Burgess Shale in Canada is one of the most famous fossil deposits from the Cambrian Explosion. It contains exceptionally preserved fossils of many bizarre and previously unknown creatures from this period, shedding light on the diversity of life at that time.
- Extinction Events: While the Cambrian Explosion was a time of rapid diversification, it was also marked by some extinction events. These extinctions were not as severe as those seen in later periods, but they did shape the course of evolution during the Cambrian.
The Ediacarans were sedentary so to what extent did the evolution of mobility contribute to the Cambrian radiation? The transition from sedentary Ediacaran organisms to mobile organisms in the Cambrian period was a significant factor in the Cambrian radiation, which was a part of the broader Cambrian Explosion. Mobility introduced new ecological and evolutionary dynamics that likely contributed to the diversification of life during this period. Here's how the evolution of mobility played a role:The discovery of these new fossil organisms from the Cambrian, showing evidence for the above, is the subject of an open access paper in Proceedings of the Royal Society B, and a press release from Leicester University. It challenges the previous view that these spikey balls were dormant cysts of single-celled organisms.It's important to note that the evolution of mobility was just one aspect of the broader environmental and biological changes that occurred during the Cambrian Explosion. Factors like increased oxygen levels, changes in sea chemistry, and genetic innovations also played important roles in driving diversification and the emergence of new body plans and species.
- Exploration of New Habitats: Sedentary Ediacarans were restricted to a particular location, primarily relying on passive suspension feeding and other stationary feeding strategies. The evolution of mobility allowed organisms to explore new habitats and access different sources of food. Mobile organisms could move to areas with higher nutrient concentrations, escape from predators, and adapt to changing environmental conditions.
- Predation and Defense: Mobility introduced the predator-prey arms race. Predators developed various strategies to capture and consume their prey, while prey species evolved mechanisms for escaping or defending themselves. The coevolution of predator and prey likely drove the development of increasingly complex and effective adaptations, including sensory organs, appendages, and protective structures.
- Competition: Mobility facilitated competition among organisms for resources, driving the evolution of diverse feeding strategies, behaviors, and body plans. This competition likely promoted the development of more complex and efficient ways to obtain and utilize resources, resulting in the proliferation of new species.
- Diversification of Lifestyles: Mobile organisms had the opportunity to exploit a wide range of niches within their ecosystems. Some became active predators, while others developed specialized modes of locomotion or feeding. This diversification of lifestyles contributed to the overall increase in biodiversity during the Cambrian Explosion.
- Innovation in Locomotion: The evolution of mobility also led to innovations in locomotion, such as appendages for swimming or crawling. This allowed organisms to access different layers of the water column or sediment, opening up new ecological opportunities.
The transition from sedentary Ediacaran organisms to mobile Cambrian organisms represented a major shift in the history of life on Earth, and it had profound effects on the development of complex ecosystems and the radiation of new species during the Cambrian period.
Abstract
The fossil record indicates a major turnover in marine phytoplankton across the Ediacaran–Cambrian transition, coincident with the rise of animal-rich ecosystems. However, the diversity, affinities and ecologies of Cambrian phytoplankton are poorly understood, leaving unclear the role of animal interactions and the drivers of diversification. New exceptionally preserved acritarchs (problematic organic-walled microfossils) from the late early Cambrian (around 510 Ma) reveal colonial organization characterized by rings and plates of interconnected, geometrically arranged cells. The assemblage exhibits a wide but gradational variation in cell size, ornamentation and intercell connection, interpreted as representing one or more species with determinate (coenobial) colony formation via cell division, aggregation and growth by cell expansion. An equivalent strategy is known only among green algae, specifically chlorophycean chlorophytes. The fossils differ in detail from modern freshwater examples and apparently represent an earlier convergent radiation in marine settings. Known trade-offs between sinking risk and predator avoidance in colonial phytoplankton point to adaptations triggered by intensifying grazing pressure during a Cambrian metazoan invasion of the water column. The new fossils reveal that not all small acritarchs are unicellular resting cysts, and support an early Palaeozoic prominence of green algal phytoplankton as predicted by molecular biomarkers.
It should be fun watching creationists tie themselves in knots over this discovery. They have to compress half a billion years into 10,000 by explaining how the scientists got their dating wrong without changing the decay rates of radioactive isotopes, which would have made the formation of atoms impossible, then force-fit the Cambrian Explosion into the creation narrative in Genesis with their creator god creating all the animals with Adam there to name them all - underwater.
Then there is the little matter of these fossils showing evidence of a transition to multicellularity!
Things just keep getting worse for creationists and their cult, if only they had the intellectual integrity to acknowledge it.
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