Architecture and Evolution: V. An Evolutionary Theory of Architecture

In biology, evolution refers to the gradual change of species over time. The theory of natural selection, which was conceived independently by Charles Darwin and Alfred Russel Wallace in the mid-19th century, has been the most popular in explaining this evolution since it was first set out in detail in Darwin’s book On the Origin of Species.

The natural selection theory of evolution is based on four observations:

1.       More offspring are often produced than can survive

2.       There exists diversity amongst individuals with respect to traits that are important for survival

3.       Different traits confer different rates of survival and reproduction

4.       These traits are partly heritable from one generation to the next

From these observations, it follows that species evolve over time towards variants that possess an optimal fitness for survival and reproduction. Those traits that confer a survival and reproduction advantage over alternatives (e.g. larger or smaller claws for a predator species), will become increasingly prevalent within that species as time passes. Variation of traits thereby gives a species the ability to adapt to different circumstances.
Circumstances change over time and vary across different geographies. Diverse species can adapt to these environments and thereby will proliferate over others that cannot.

The theory follows logically from the observations. If the observations are accurate, the evolutionary theory of natural selection must be true as well.
As with species, there exists (or used to exist) a natural process of evolution in architecture as well. Whereas the previous articles in this series showed that our aesthetic preferences result from the evolution of our species, this article is about the evolution of architectural form itself, which is closely linked with our innate preferences. In this article I will set out a theory of aesthetic selection that largely explains the evolution of architecture.

Aesthetic Selection

Until the advent of modernism, the architectural profession strived for both practicality and beauty. Beauty was created through adorning structures with ornament and abiding by the principles for beauty that stem from our nature. Architects took inspiration from each other’s work and experimented with new forms and variations, many of which they subsequently published for others to copy.
Architecture evolved through a decentralised process of evolution. Some forms and variations of forms were found more beautiful than others and were copied more often. Styles were thereby refined over time and those best adapted to our nature prevailed as a result. Citing James Ward, historian:

‘It is rather to the inventive faculties of man, than to hints supplied by nature, that we must look for the origin and development of what is called style in architecture or ornament. In every case this is arrived at by a slow process, and by the extensive and persistent use of distinguishing features selected according to the needs and requirements of the time, to satisfy the prevailing tastes.’

(James Ward, Historic Ornament, published 1897)


This is how architectural innovation used to take place. As will be shown later in this series, the conditions necessary for this evolutionary process mostly no longer hold, resulting in architecture that is maladaptive to our innate preferences.

Like species, architectural styles (or orders) evolve through a process of selection after they emerge. This process adapts a style to the aesthetic preferences of man, which manifests itself in many details and refined proportions that distinguish great architecture from the mediocre. After the emergence of the classical orders, each of them developed through a process of variation, copying and inspiration and consequently refinement. Over time, conventions emerged, which were well-documented. To this day, these records give architects a great source of inspiration for detailed ornaments and exact proportions that make a great building.

Examples of ‘evolutionary steps’ can be found in plenty in the ruins of what used to be classical civilisation. For example, in the Valley of the Temples in Agrigento, Sicily, one can find many ruins of temples built in the Doric order. They are an heirloom from a bygone era, left by the Greek colony that once existed there.
The proportions of these temples and their elements differ from those in the first temple of Hera at Paestum and from those in the Parthenon in Athens. This provides an insight in how architectural styles evolve over time. As with species, multiple variants can exist side by side for a time. Those variants that are better adapted to the aesthetic preferences of man will become dominant as time passes. Whereas there exists much diversity in the beginning, more homogeneity eventually emerges, leaving a style that is perfected through many small iterations, like rocks smoothened over the millennia by the flow of a river.

Figure 4.1. The Doric Temple of Concordia in Agrigento, Sicily, built around 440-430 BC.

Figure 4.2. The Doric columns of the first Temple of Hera in Paestum, Italy, built between 570 and 520 BC¹. (De Jong 2010, 20-24; Gates 2011, 312-314.

Figure 4.3. The Parthenon in Athens, Greece, built between 447-432 BC.


As can be seen in figures 4.1, 4.2 and 4.3, Doric columns used to differ across different temples. This is a good example of how architectural forms vary, allowing architects to draw inspiration from and copy different variants. Over time, analogous to the evolution of species, some variants go extinct, leaving only the ones that are optimally adapted to human preferences. In the case above, the Doric column in the first Temple of Hera in Paestum has gone extinct.

Over the recent centuries, architectural evolution has quickened. ‘New’ innovations for the exchange of ideas have enabled architects to learn from one another internationally. An architect can nowadays effortlessly draw inspiration from designs conceived across the globe. Through the power of the printing press and more recently the internet, designs can spread across the world at an unprecedented pace. Meanwhile, technical innovations and a general increase in prosperity have enabled the architectural profession to explore previously unchartered waters. As a result, sophisticated new designs have emerged over the centuries, together forming the baroque and ensuing styles, and outperforming the classical orders in their grandeur and aesthetic appeal.

Analogous to the observations that underpin Darwin’s natural selection theory, the following historical observations can be made:

1.       Architects conceived and experimented with new forms and variations of forms. Many of these new designs were built and many were published.

2.       Different forms and variations possess varying degrees of beauty. Some appeal more to our innate aesthetic preferences than others.

3.       Architects drew inspiration from and copied each other’s work, selecting for beauty. They designed for beauty, first and foremost – Not for uniqueness.

From these points, the aesthetic selection theory of the evolution of architecture follows logically.

With respect to the first observation, the following is important to note: The fact that many designs were in fact built, allowed for architects to analyse, copy and draw inspiration from each other’s designs by travelling to them. This is, however, a tedious process, but nonetheless one that has been vital in architectural history. The early architects of the Renaissance, as well as later architects of the Baroque and other styles, travelled to the great heirlooms of classical antiquity to collect detailed measurements and drawings for inspiration and publishing. At current, most transmission of designs happens through mediated communication, such as over the internet and through books. Since the invention of the printing press, many designs were published for others to copy, which removed the need for architects to travel to buildings for inspiration. This significantly eased the process of architectural evolution through aesthetic selection.

There exist many historical examples that illustrate the first point, amongst which we can find not just many built examples, such as the temples in figures 4.1, 4.2 and 4.3. In fact, the famed Ten Books on Architecture written by the great Roman architect Marcus Vitruvius Pollio provide one of the earliest examples, if not the earliest example, of the mediated transmission of architectural design. This work contained detailed specifications for how to build temples, markets and other complexes, as well as exact proportions for architectural components such as columns. It has served as an inspiration for many architects after Vitruvius and still serves as an important historical reference point in classical architecture.
Many architects followed in Vitruvius’ footsteps. For example, the great Renaissance architects Brunelleschi (known for designing the dome of the cathedral of Florence) and Donatello were inspired by Rome’s ancient ruins and travelled to Rome together to study them. They left Rome with measurements and designs which they applied in their own architecture.
In the sixteenth century, one of the great architects of the Italian Renaissance, Andrea Palladio, wrote an important masterpiece. His book, The Four Books of Architecture, provided detailed instructions and proportions based on his own expertise. Many of his great architectural works, such as the Villa Rotonda and the church of San Giorgio Maggiore, still stand to inspire their viewers.

Figure 4.4. The Church of San Giorgio Maggiore, Venice, Italy. Designed by Andrea Palladio and built between 1566 and 1610.


The exchange of designs continued after the Renaissance. As Figures 3.15 and 3.16 in the previous article in this series show, illustrations of designs were printed and sold throughout the centuries.

Not only new designs were published. Copying elements of the great works of antiquity also continued after the Renaissance. In 1682, Antoine Desgodetz’ book Les Édifices Antiques de Rome was published, which contained detailed illustrations and measurements of the buildings of antiquity that could be found in Rome.

To those familiar with the history of architectural practice, the second point will be evident. Architecture is, above all, an art that evolves over time through trial and error. One cannot accurately know in advance how human viewers will experience a design. The only sure-fire way to assess the beauty of designs and variations is by constructing them and experiencing the result first-hand. The proof of the pudding is in the eating, as the saying goes.
The experience of beauty is a human emotion. Beauty is therefore impossible to quantify or measure. But as anyone familiar with modern architecture and recent attempts at building ‘classical’ architecture knows, some buildings are more beautiful than others. Although it is certainly possible, it is not necessary to elaborate on this or to attempt to prove it by providing data. It is evident to anyone with a conscious experience of the built environment. The fact that many people consciously find some buildings beautiful and find this worth mentioning, implies that not all buildings are. This by itself proves our second observation.

The third observation is trickier. It cannot be measured, nor quantified, to what extent beauty is part of the considerations of architects. Some generalising statements comparing modernism with pre-modern architectural periods in this respect could perhaps be made with a high degree of certainty. This does, however, not prove the argument. But as will be shown this does not matter for the conclusions of this series.
What is in fact evident, is that architects copy, learn and draw inspiration from each other’s work. This has always been the case. Otherwise, architectural orders and styles could not have emerged. Every structure would differ starkly from any other, whereas one can easily observe large degrees of homogeneity within styles, classical orders and periods throughout the history of architecture.

The long and intensive process of evolution in architecture has given historical styles a great grandeur and beauty. This is what has made pre-modern architecture so cherished. It is what drives millions of tourists to cities like Venice and Florence every year. Within the distinct architectural styles, including the classical orders, this evolution has resulted in many conventions and details that distinguish the great buildings from the mediocre.
For example, this process of evolution through testing the pudding by eating it, varying and experimenting with design and copying what is beautiful, has lead to architectural solutions to the optical illusions to which the human eye is prone. One such solution is what is called entasis, which is the application of a convex curve to a surface. Entasis is mostly applied to the design of columns, which gives them greater aesthetic appeal. The most widespread explanation for entasis is that it serves to correct for an optical illusion that makes straight columns look concave. This view was espoused as early as in the first century AD by Hero of Alexandria.

Many other corrections for optical illusions exist. Citing Vitruvius:

‘Then, too, the columns at the corners should be made thicker than the others by a fiftieth of their own diameter, because they are sharply outlined by the unobstructed air round them, and seem to the beholder more slender than they are. Hence, we must counteract the ocular deception by an adjustment of proportions.’

(Marcus Vitruvius Pollio, The Ten Books on Architecture)

And, as historian James Ward wrote:

‘Some very subtle devices to overcome natural optical effects when viewing the buildings have been discovered by Mr. Pennethorne and Mr. Penrose, more especially in the Parthenon.’

(James Ward, Historic Ornament, published 1897)

The rejection of the conventions and details that have resulted from architectural evolution leads to disappointing designs, such as those of the countless ‘McMansions’ that have been built in the United States. They are good examples of failed attempts to mimic evolved architectural styles whilst rejecting essential parts of what this evolution has left us. Evolved architecture does not leave much room for architects to deviate from existing designs if their aim is to optimise for beauty.
In fact, if we add the axiom that room for improvement with respect to beauty is finite, we obtain one more important insight.
That is, the more beautiful existing architecture is, the more difficult it becomes to create more beautiful designs by deviating from what already exists in the realm of architecture. Architects must therefore be willing to copy. The more beautiful the most aesthetically appealing architecture in existence is, the greater the degree to which architects ought to copy others.
In more simple terms: The more innovations have been made, the less room for innovation there is left and the more reason there is to copy. Architects and developers should take note of this insight, as it would lessen their temptation to strive for uniqueness and could provide a sobering perspective on the phenomenon of Starchitecture.

As explained above, if the conditions above hold, architectural evolution partly happens through aesthetic selection and results in styles optimally adapted to our aesthetic preferences. Whether our aesthetic preferences are innate is of no importance for this conclusion. The aesthetic selection theory of architectural evolution will still be true.
Besides, if some of these observations cannot be made with much rigour, such as whether beauty has been an important consideration for architects in their designs, is not relevant for this series’ most important conclusions. An evolutionary process based on aesthetic selection, wherein the principles above hold, will result in architecture that is optimally adapted to our innate and universal aesthetic preferences. It will bring about an adaptive architecture, as opposed to the maladaptive architecture that is not born out of this process. As will become evident later in this series, this is the most important takeaway of this article.

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1. De Jong 2010, 20-24; Gates 2011, 312-314