Showing posts with label LUCA. Show all posts
Showing posts with label LUCA. Show all posts

Monday, 7 September 2026

Creationism Refuted - How LUCA Got It's Enzymes - No Magic Required

Metabolic networks provide clues about the earliest stages of enzyme evolution | Science Tokyo
Metabolic Reactions Reveal Early Enzyme Evolution
One of creationism’s more persistent claims is that evolution cannot produce “new genetic information” because doing so would violate the second law of thermodynamics. The proposed escape from this imaginary prohibition is, inevitably, a supernatural information-provider. But the second law contains no ban on mutations producing new biological functions. It concerns entropy: the total entropy of an isolated system cannot decrease. Living organisms exchange energy and matter with their surroundings, and their activities increase the entropy of those surroundings. Building DNA, growing a leaf and evolving a new enzyme require no suspension of physics. The thermodynamic principles are explained here.

The argument also trades on treating genetic “information” as though it were a mysterious substance that only intelligence can manufacture. Genes are physical sequences of DNA, and those sequences can change, duplicate and recombine. Following duplication, one copy can retain an established function while the other accumulates changes that enable a different or more specialised activity. Natural selection can favour useful variants. A new biological capability need not require an entirely new molecular structure, still less a miraculous delivery of instructions.

This is what makes a study by Tatsuya Corlett and colleagues, published in PNAS, particularly relevant. The researchers combined metabolic-reaction networks with protein-fold data to infer the relative order in which enzyme structures emerged. Their model points to a prominent early role for α/β folds—structures containing both alpha helices and beta sheets—and suggests that most oxygen-using enzymes arose through the adaptation of existing folds as oxygen became available. Evolution could expand its biochemical repertoire by modifying structures already present.

The creationist demand for something wholly unprecedented therefore misses how evolution works. Novelty can reside in a changed activity, a different molecular target or a new regulatory relationship. Retaining an ancestral protein framework does not make a newly evolved function any less new. Nor does calling the result “information” establish a thermodynamic obstacle to its origin.

The research also extends the investigation of our shared biochemical ancestry towards the interval before LUCA, the last universal common ancestor of living organisms. LUCA was not necessarily the first life: its enzymes already had an evolutionary history. These results are model-based historical inferences, rather than recovered pre-LUCA proteins or a direct measurement of increasing genetic information. Nevertheless, they offer a way to investigate that earlier history through the organisation of metabolism itself.

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