Unintelligent Design - Flatworms Can Regenerate Body Parts - So Why Can't Humans?

The planarian Schmidtea mediterranea

Credit: FLI / Anna Schroll

Schmidtea mediterranea

New research shows a tiny, regenerative worm could change our understanding of healing Stowers Institute for Medical Research

Researchers at the Stowers Institute for Medical Research have uncovered new details explaining how the planarian flatworm, Schmidtea mediterranea, can regenerate not just a missing body part, but an entire organism from a tiny tissue fragment. Their findings have just been published in Cell Reports and represent a major advance in our understanding of regeneration at the cellular and genetic level.

This little worm continues to surprise scientists. Remove its head? It grows a new one. Slice it into pieces? Each piece becomes a complete worm. Such astonishing powers naturally prompt two very different kinds of questions – one scientific, one theological.

If one temporarily accepts creationist premises for the sake of argument, we are forced into a series of uncomfortable and contradictory conclusions.

Why would a supposedly omniscient, omnipotent, and omnibenevolent designer grant a humble flatworm the ability to regenerate an entire body, yet deny this life-saving ability to humans and virtually all other organisms? If this designer could abolish suffering, disease, and limb loss – and knowingly chose not to – what does that imply about its nature?

Creationists are left defending a worldview in which their designer appears either: unwilling to prevent suffering; unable to create beneficial traits consistently; or deliberately designing suffering into its creation. None of these options are theologically tidy – and they certainly do not align with the claim of a universally benevolent designer. The creationist framework produces contradictions, apologetics acrobatics, and moral dilemmas rather than answers.

By contrast, when we ask the evolutionary question – “How did this ability evolve?” – the picture becomes coherent.

Planarians have followed a unique evolutionary trajectory in which extreme regeneration conferred a significant survival advantage. Natural selection acted on stem-cell behaviour, gene regulation, and patterning networks over deep time, refining a mechanism that happens to be far beyond the needs of most other species.

Other organisms have regenerative abilities too – salamanders, zebrafish, sea stars, even humans to a limited extent – but the selective pressures and biological constraints differed. Regeneration is complex, energetically costly, and evolution works from what already exists. Most lineages simply did not follow that path. To borrow Michael Behe’s favourite term, planarian regeneration may appear “irreducibly complex” – and yet, as usual, complexity proves to be a testament to gradual evolutionary refinement, not evidence for supernatural assembly.

Creationism Refuted - How Micro-oranisms Acquire New Genetic Information - Millions of Times A Day

AI generated image

ChatGPT 5

Researchers Quantify Rate of Essential Evolutionary Process - Bigelow Laboratory for Ocean Sciences

Researchers at Bigelow Laboratory for Ocean Sciences (East Boothbay, Maine, USA) have recently quantified a remarkable evolutionary process: a typical marine microorganism acquires and retains approximately 13% of its genes per million years through horizontal (lateral) gene transfer. This rate corresponds to roughly 250 genes exchanged and retained per litre of seawater each day

These transferred genes include those that provide either a selective advantage or are sufficiently neutral to persist via genetic drift—both well-established mechanisms of evolutionary change.

Some creationist arguments misapply Shannon Information Theory, claiming that gaining new genetic information violates the laws of thermodynamics. However, such arguments disregard key biological realities: cells are open systems capable of energy and material exchange; genome duplication and horizontal transfer are well-documented evolutionary processes; and substituting one nucleic acid for another does not create matter ex nihilo - facts of which any qualified biological scientists should be aware.

Furthermore, the successful retention and spread of horizontally acquired genes within microbial genomes provide clear, empirical evidence of Darwinian evolution in action. Although Charles Darwin formulated his theory without the concept of genes — speaking instead of 'heritable traits' — his mechanism of natural selection precisely explains how heritable variations can spread through populations over time.

This study also highlights that microorganisms can evolve not only through mutation and selection but also by acquiring pre-adapted genes from their environment, often from distantly related organisms. Consequently, these newly acquired genes can propagate rapidly within the recipient lineage.

The findings further challenge traditional microbial taxonomy, blurring species boundaries at the genetic level: horizontally transferred genes may function just as effectively in their new hosts as they did in their original genomes, thanks to the universality of underlying molecular machinery (e.g., replication and translation systems).

Refuting Creationism - LECA Was An Asgard Archaea

An artist’s depiction of an Asgard archaeon, based on cryo-electron tomography data: the cell body and appendages feature thread-like skeletal structures, similar to those found in complex cells with nuclei.

Graphic: Margot Riggi,
Max Planck Institute of Biochemistry

Asgard tubulin.

Origin of Life: How microbes laid the foundation for complex cells | ETH Zurich

Recent research indicates that the last universal common ancestor of complex (eukaryotic) cells, which encompass all multicellular plant and animal life, likely originated from the Asgard group of archaea. This ancestor is believed to have formed a symbiotic relationship with an alphaproteobacterium, which eventually evolved into the mitochondrion.

The initial nature of this symbiotic relationship—whether parasitic or predatory—remains uncertain. However, its establishment was pivotal in setting the evolutionary course that led to the diversity of life on Earth. Compelling evidence supporting the Asgard archaea hypothesis has been uncovered by Professor Martin Pilhofer and his team at the Eidgenössische Technische Hochschule (ETH) Zurich, Switzerland. Their findings have been published in the journal Cell and is explained in an ETH news item by Peter Rüegg: