Unintelligent Design News - The Needless Complexity of Acoels-Microalgae Symbiosis

Acoel, a primitive flatworm-like multicellular marine organism

Photo: Christopher Laumer

A simple, multicellular, acoel.

Shining a light on tiny, solar-powered animals | Hokkaido University

Let's step into fantasy land and assume the creationist superstition of an intelligent [sic] designer is true for a moment.

Once upon a time this designer designed photosynthesis and put it in the cyanobacteria, which meant they were able to live on sunlight and carbon dioxide (CO₂whilst giving off oxygen as a waste product. It didn't do a particularly decent job of it and included probably the least efficient known enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCo), but that’s another story.

Later on, it decided simple plants called algae also needed to live on sunlight and CO₂, so what did it do? Instead of doing what any normal intelligent designer would do and give them the same process it gave to the cyanobacteria, it put lots of cyanobacteria inside the algae, where they became the chloroplasts! Apparently, the simple solution wasn't complex enough.

Later on, this same designer decided a group of primitive multicellular marine flatworm-like organisms called acoels also needed to live on sunlight and CO₂, so what did it do? Did it give them the same process it had designed for the cyanobacteria? Of course not! Did if put cyanobacteria into the cells of the acoels like it had the algae? Of course not! Those would be simple solutions to the problem.

This time it didn’t even needlessly increased the complexity of acoels by putting whole algae, containing the cyanobacteria, inside the acoel cells. It went for an even more complex solution. Bizarrely, it actually designed the acoels to find and capture photosynthetic algae and insert them into their own cells!

So much for creationists superstitions and their idiotic insistence that maximal complexity is evidence of intelligent design, not minimal complexity, as any normal intelligent designer would design for. Needless complexity is actually evidence for unintelligent design.

Tell me all about the marine organisms called acoels. Acoels, also known as Acoela, are a group of small, marine flatworms that belong to the phylum Acoelomorpha. They are relatively simple organisms, but they have attracted significant attention from scientists due to their unique characteristics and evolutionary significance. Here's some important information about acoels:

1. Taxonomy and Classification:
   • Acoels are classified within the phylum Acoelomorpha, which is considered one of the most basal groups of bilaterally symmetric animals (Bilateria). Their exact placement within the animal kingdom has been a subject of debate, and they were once thought to be related to flatworms (Platyhelminthes). However, recent molecular studies suggest that they might represent a distinct lineage.
2. Anatomy and Morphology:
   • Acoels are generally small, ranging in size from a fraction of a millimeter to a few centimeters in length.
   • They have a simple, flattened body plan with a soft, unsegmented body and no body cavity (acoelomate).
   • Acoels lack specialized respiratory, circulatory, and excretory systems.
   • They possess a simple, blind-ended gut, with a single opening serving as both the mouth and anus.
   • Sensory organs, called statocysts, are present, allowing them to sense gravity and maintain orientation.
3. Feeding and Digestion:
   • Acoels are primarily carnivorous, feeding on microorganisms, small invertebrates, and detritus in their marine habitats.
   • They use a muscular pharynx to engulf and digest their prey.
4. Reproduction:
   • Acoels reproduce both sexually and asexually.
   • Asexual reproduction can occur through fragmentation, where a part of the body can regenerate into a new individual.
   • Sexual reproduction involves the exchange of gametes (sperm and eggs) between two individuals. Some species are hermaphroditic, meaning they have both male and female reproductive organs.
5. Ecology:
   • Acoels are predominantly marine organisms and are found in various marine habitats, including intertidal zones, sandy bottoms, and coral reefs.
   • They can be abundant in some environments, playing a role in nutrient cycling and ecosystem processes.
6. Evolutionary Significance:
   • Acoels are of interest to scientists because of their primitive characteristics, which provide insights into the early evolution of bilaterian animals.
   • They lack many of the complex structures and features found in more advanced organisms, making them valuable for studying the origins of more complex body plans.
7. Conservation Status:
   • Acoels are not typically a focus of conservation efforts, as they are relatively unstudied compared to other marine organisms. However, their habitats may be threatened by pollution, habitat destruction, and climate change.

It's important to note that research on acoels is ongoing, and our understanding of these organisms continues to evolve as new discoveries are made. Additionally, the taxonomy and classification of acoels are still subjects of scientific debate, and their exact relationship to other animal groups remains a topic of study and discussion.

The symbiotic relationship between photosynthetic microalgae and acoels was the subject of a study by two scientists based at Hokkaido University, Japan, undergraduate student, Siratee Riewluang, and Assistant Professor Kevin Wakeman. Their findings are published open access in the PeerJ journal, Aquatic Biology, and is the subject of a research press release from Hokkaido University:

Acoels have been found to host a wide diversity of symbiotic, photosynthetic microalgae.

Animals and plants need energy. Some animals get energy by eating other animals, and many plants harvest the energy in sunlight through photosynthesis. However, in the ocean, there exists a remarkable group of small, worm-like animals called acoels that do both—some acoels form relationships (symbiosis) with single-celled, photosynthetic microalgae.

An acoel (top) with two types of symbionts collected in Kochi, Japan (bottom left). The green-colored spots in the acoel are green algal (Tetraselmis) symbionts (middle right) and the brown-colored spots are dinoflagellate symbionts (bottom right).

Photos: Kevin Wakeman and Siratee Riewluang

A study by Assistant Professor Kevin Wakeman and his undergraduate student, Siratee Riewluang, at Hokkaido University, Japan, has shed some light on the biodiversity underpinning symbiotic relationships between acoels and microalgae. Their findings were published in the journal PeerJ.

Acoels are superficially simple. However, this simplicity is misleading. Due to their regenerative ability and position as one of the first animal groups on the planet, acoels interest biologists in the fields of evolutionary biology, regenerative biology, and neurobiology. Some acoels also form symbiotic relationships with microalgae. This includes green algae and other types of microalgae that also associate with coral reefs called dinoflagellates.

An acoel with dinoflagellate symbionts (brown color). The acoel was collected from Okinawa, Japan, and was about 1 mm in length. This particular acoel is of interest because it may be a new group of acoels containing symbiotic microalgae.

Photos: Kevin Wakeman and Siratee Riewluang.

These acoels engulf microalgae seemingly as ‘food’, but they do not digest them. Instead, they store them below their outer surface. They create energy using sunlight—much like adding solar panels to your house.

Photosynthetic acoels are mostly found in warmer waters. Therefore, we focused our sampling in Southern Japan. We also found acoels near Kochi, a region of Japan that receives warm water from the Kuroshio Current. Photosynthetic acoels can be difficult to spot—they are microscopic. But, under a microscope they are easily recognizable, by their brightly colored algae.

It would be cool to figure out if they really are a new group of acoels with symbionts, but we need more genetic data and unambiguous morphological data to confidently assign a new name. Eventually, I would like to use advanced imaging and genetics to explore these acoels at a molecular level.

Siratee Riewluang, first author
Hokkaido University

Throughout 2022, Wakeman and Siratee collected algae and sediment samples. The host acoel and their symbionts were identified by DNA sequencing. Symbiotic microalgae were removed from acoel hosts and put into culture. This study found that acoels contained various green algae (Tetraselmis); previously, only one species was known. Several dinoflagellate lineages were also found. Most belonged to the Symbiodiniaceae, a group famously associated with coral (and other invertebrates). Some of these Tetraselmis and dinoflagellates might be new to science.

Unexpectedly, Wakeman and Siratee came across what might turn out to be a whole new group of acoels harboring symbionts (only one group is currently known).

We found that there was more diversity of acoels and their symbionts than we really expected. Even in this present dataset, which focuses on Japan, it’s clear that there are fascinating interactions between acoels and microalgae. These results will lay the groundwork for future studies that can tease apart what are probably some interesting ecological mechanisms. I really am excited to see where this ends up.

Assistant Professor Kevine Wakeman, co-author
Hokkaido University.

Wakeman and Siratee will continue work on photosynthetic acoels for Siratee’s Master’s.

Unlike an intelligent design process, where one of the objectives is to reduce complexity and the waste that goes with it and seek the minimal necessary complexity to achieve the desired outcome - in this case, enabling firstly the algae, then the acoels to live on sunlight and CO₂, and having already designed a process which does the job, any intelligent designer would simply insert that process into the other organisms that need it.

But evolution is not an intelligent design process. It has no plan, no objectives, and no blueprint. It is purely utilitarian - whatever improves the current situation will tend to proliferate in the species gene pool and, if the improvement is large enough, will quickly become fixed in the gene pool, maybe even giving rise to an entirely new species.

So, evolution has given us the ludicrously complex system of symbiosis between an alga, which is already in symbiosis with a cyanobacterium, and a primitive multicellular animal, so the latter can live on sunlight and CO₂.

This is how we know that processes such as this have evolved and were not designed, either intelligently, or incompetently.

An added embarrassment for creationists, is the fact that the new genetic information in the acoels' genome which enables them to engulf microalgae and dinoflagellates and insert them into their cells, has given them a new capability and a radical change in life-style. In other words, it is an example of 'macro-evolution', as creationists define it.

So, creationists need to decide whether this 'macro-evolutionary' adaptation to photosynthesising in acoels is the result of unintelligent, incompetent design or of a mindless, utilitarian evolutionary process, working without plan, blueprint or objectives.

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