
One common way creationist apologists attempt to mislead the scientifically uninformed is by claiming that the Laws of Thermodynamics are somehow relevant to the evolution of information within a species' genome. They argue that any increase in genetic information would violate both the Second and Third Laws of Thermodynamics—asserting that increased biological complexity equates to a decrease in entropy (disorder), and that new information is akin to energy and thus cannot increase due to the Law of Conservation.
This argument is fundamentally flawed on several levels but continues to be repeated despite being repeatedly refuted by both biologists and physicists. First, it completely ignores the fact that Earth is not a closed system. The input of energy from the Sun, for example, allows local decreases in entropy (such as in the formation of complex biological structures) while the total entropy of the universe still increases, fully complying with the Second Law. The Third Law, which relates to the entropy of systems at absolute zero, is entirely irrelevant to biological evolution.
Second, the idea that genetic information is conserved like energy is a misrepresentation. Genetic information can and does change in multiple ways through mutation. A mutation can involve the loss of information (e.g. deletion of a DNA segment), a change in information (e.g. substitution of one or more nucleotides), or an increase in information (e.g. insertion of additional sequences, or the movement of transposable elements—“jumping genes”—to new locations in the genome). None of these processes require a change in the total amount of matter or energy; they simply involve the rearrangement of existing molecular components. Any local increase in biological order is offset by energy expenditure elsewhere, typically via the hydrolysis of ATP to ADP and phosphate within metabolic pathways.
Moreover, these objections rest on the false assumption that evolution is about the quantity of information. In reality, it is the function and meaning of genetic information that drives evolutionary change. A sequence of DNA that once encoded a protein with one function can, through mutation and natural selection, take on a new function entirely—a process known as exaptation.
A well-known example is the evolution of the mammalian middle ear bones. In ancestral fish, certain jawbones played a structural role in the jaw joint. Over time, in early synapsids, these bones were repurposed and miniaturised to become part of the auditory system, transmitting sound vibrations from the eardrum to the cochlea.