Biological Explanation — What Needs to Be Explained

What Does Biology Explain?

Biology is often described as the science of life. But this leaves open a deeper question: what does biological explanation actually explain?

Standard answers point to mechanisms, components, or processes. Biology explains how genes are expressed, how metabolic pathways operate, how organisms develop, and how populations evolve. These explanations have achieved extraordinary success.

Yet they often proceed without specifying what makes their subject matter distinctively biological. They describe how systems behave, but not what makes those systems living.

The central question is therefore not only how biological systems work, but what kind of biological organisation must be in place for such explanations to be meaningful.

APS argues that the ultimate target of biological explanation is organised persistence: the capacity of living systems to maintain continuity through continual transformation. Living systems are not merely collections of interacting components. They are organised systems that sustain themselves through ongoing change.

For a guided entry into how APS develops biological explanation, see:

→ How APS Explains Life — A Two-Step Guide

Mechanism and Its Limits

Much of modern biology is organised around mechanistic explanation.

Mechanistic accounts identify parts, specify their interactions, and show how these interactions produce observable outcomes. This approach has been highly productive, especially in molecular and cellular biology.

However, mechanism alone does not explain why a system is a living system rather than a complex physical arrangement.

A mechanism can operate without sustaining itself. It can produce outputs without maintaining the conditions required for its own continued operation. In such cases, the system remains externally grounded: its persistence depends on conditions imposed from outside.

Living systems differ in a crucial respect. Their processes contribute to maintaining the very conditions that allow those processes to continue.

Mechanistic description captures how organised persistence is enacted. It does not, by itself, explain why those processes are organised in a way that contributes to the continued existence of the living system.

Biological explanation therefore requires more than identifying mechanisms. It requires understanding how mechanisms participate in the organisation of living systems.

From Description to Explanation

This distinction reveals a deeper issue.

Descriptions catalogue what happens. Explanations account for why it happens in a way that is characteristic of the system under study.

In biology, description often precedes explanation. We identify structures, trace pathways, and measure changes. But without a clear account of what makes these processes biologically organised, such descriptions risk remaining incomplete.

A fully biological explanation must therefore do more than specify mechanisms. It must account for the biological organisation that makes those mechanisms part of a living system.

The question is not simply:

What happens?

but:

Why do these processes contribute to the persistence of a living system?

Answering that question requires identifying the organisational conditions that make biological continuity possible.

Organised Persistence as the Explanatory Target

The APS framework clarifies this target.

Biology is ultimately concerned with systems that maintain themselves through time. Living systems grow, repair, regulate, adapt, reproduce, and evolve, yet throughout these transformations they preserve forms of organisational continuity.

This capacity for continuity through change is what APS calls organised persistence.

Organised persistence is therefore the central explanatory target of biology.

Understanding how living systems persist requires understanding the organisational conditions that make persistence possible.

Within APS, two concepts are particularly important. The first is viability orientation. Living systems are organised in ways that tend to preserve the conditions required for their continued existence. Their activity is not merely coordinated; it contributes to maintaining viability.

The second is constraint closure. The processes of the system contribute to maintaining the constraints that enable those very processes to occur. Living systems therefore participate in sustaining the organisational conditions upon which they depend.

Together, viability orientation and constraint closure help explain how biological continuity is maintained through change.

Biological explanation must therefore account not merely for what living systems do, but for how their activity contributes to maintaining continuity across changing conditions.

Without this organisational perspective, explanations remain partial. They describe processes, but do not fully explain why those processes are biologically significant.

Agency and Normativity in Explanation

Once organised persistence is recognised as the explanatory target of biology, additional features of living systems become easier to understand.

Living systems exhibit biological agency. Their activity is organised around maintaining the conditions required for continued existence. Organisms regulate internal conditions, respond to environmental change, repair damage, acquire resources, and modify behaviour in ways that contribute to persistence.

This introduces a form of biological normativity. Because living systems can succeed or fail in maintaining themselves, biological activity possesses an inherently normative dimension.

Some states support persistence. Others undermine it. Some processes contribute to viability, while others impair it. The distinction between success and failure therefore arises from the organisation of the living system itself rather than from external evaluation.

This is why biological explanations routinely employ concepts such as function, regulation, adaptation, success, failure, and malfunction. These concepts reflect real features of systems whose activity is organised around persistence.

To explain a biological process is therefore to explain how it contributes—successfully or unsuccessfully—to the continued viability of the system.

Process and Scale in Biological Explanation

Organised persistence unfolds through process and across scale.

Living systems maintain continuity not by remaining unchanged, but by continually transforming. Metabolism, development, behaviour, ecology, and evolution all involve processes through which continuity is preserved despite ongoing change.

At the same time, biological organisation extends across multiple scales. Molecular processes contribute to cellular organisation, cells contribute to organisms, and organisms participate in ecological systems. These scales interact continuously and cannot be understood in isolation.

Biological explanation must therefore account not only for mechanisms, but also for the processual and multiscale organisation through which persistence is maintained.

Beyond Gene-Centric and Trait-Based Accounts

Many explanatory frameworks in biology focus on genes, traits, or population-level patterns.

These approaches provide powerful explanatory tools. However, they presuppose systems capable of maintaining organised persistence.

Genes influence biological outcomes only within living systems capable of sustaining development, regulation, and reproduction. Likewise, evolutionary processes depend upon organisms that survive, reproduce, and maintain continuity across generations.

APS therefore shifts attention from isolated explanatory units toward the organisational conditions that make those units biologically meaningful.

The question is not whether genes, traits, or populations matter. It is how they participate in the organised persistence of living systems.

Explanatory Adequacy in Biology

What counts as an adequate biological explanation?

APS argues that an explanation becomes biologically adequate when it clarifies how identified processes contribute to the organised persistence of a living system. An explanation may correctly identify a cause while remaining biologically incomplete. Likewise, a mechanism may be accurately described while its significance within the organisation of the system remains unclear.

Biological adequacy therefore requires more than causal identification alone. It requires understanding how processes contribute to viability, continuity, and persistence. The detailed implications of explanatory adequacy are developed in Biological Explanation and Organised Persistence, which examines how APS functions as an explanatory grammar for biological explanation.

Why This Matters

Clarifying the target of biological explanation has both conceptual and practical consequences.

It helps explain why concepts such as function, regulation, adaptation, resilience, and malfunction remain indispensable within biology. These concepts are not optional additions to biological discourse. They reflect the organisational realities of systems that must maintain themselves through time.

It also clarifies the relationship between different explanatory traditions. Mechanistic, developmental, ecological, and evolutionary explanations need not compete for explanatory priority. Each illuminates different aspects of the organised persistence of living systems.

The framework is equally relevant to questions at the boundaries of biology. Understanding what biological explanation explains helps clarify how life might be identified in unfamiliar contexts, how synthetic systems should be evaluated, and how biological continuity can be recognised across diverse forms of organisation.

Most importantly, APS makes explicit the organisational assumptions that successful biological explanations already rely upon. Biologists routinely explain persistence, adaptation, regulation, repair, and continuity. APS seeks to clarify the organisational reality that makes these explanatory practices intelligible as biology.

To specify what biological explanation must explain, however, is only the first step.

A further question immediately follows:

How should biological explanations be structured in order to explain organised persistence?

This question is addressed in Biological Explanation and Organised Persistence, which develops APS as an explanatory grammar and examines how biological explanations achieve explanatory adequacy.

Conclusion

Biology does not simply explain biological events. It explains how living systems persist.

The distinctive challenge of biological explanation is therefore not merely to identify causes, mechanisms, or patterns, but to explain how living systems maintain continuity through continual transformation.

APS proposes that the central explanatory target of biology is organised persistence.

Living systems persist because their activity contributes to maintaining the conditions required for their continued existence. Viability orientation helps explain why persistence is maintained. Constraint closure helps explain how persistence is maintained. Together they illuminate the organisational basis of biological continuity.

Understanding this target clarifies why biological explanations differ from explanations in many other domains. Biological explanation is concerned not merely with what happens, but with how organised systems sustain themselves through time.

By identifying organised persistence as the phenomenon requiring explanation, APS provides a unified way of understanding what biological explanation is ultimately about.

Identifying what biological explanation explains is only the first step. The next question concerns how such explanations are constructed. For this, see:

→ Biological Explanation and Organised Persistence

which develops APS as an explanatory grammar for understanding how organised persistence is explained across agency, process, and scale.