But evolution eventually crossed paths with another possible function: to control the movement of air around the feathered extremities, which allowed a primi-tive form of gliding. This is an example of what paleontologist Stephen Jay Gould called exaptation, by which a trait that evolves in response to an environmental challenge is used for an entirely different purpose (flying).

Exaptations are common in technology as well. The Internet could be analyzed as an exaptation. Designed to enhance communication between scientists, it ended up being adopted by the public as a virtual world that facilitates many kinds of human sharing. Guttenberg’s printing press was based on technologies previously used to crush grapes and make wine. The original function of presses was to crush grapes, and their form was well suited to that function. It just hap-pened that someone eventually saw that the form of those machines could have an entirely different function.

For my purposes in this book, information graphics and visualization is a form of information architecture. But how can we be more precise in describing the relationship between the branch and the trunk? [...] Among the most relevant disciplines is information design, defined by Stanford University’s Robert E. Horn as “the art and science of preparing information so that it can be used The goal of the information by human beings with efficiency and effectiveness.”8 designer is to prepare documents (both analog and digital) and spaces so they can be navigated effortlessly. [...] A significant part of information design is information graphics and visualization. Academic literature sometimes separates infographics from visualization and defines the latter as “the use of computer-supported, interactive, visual repre-sentations of data to amplify cognition,” [...] To visualize is “to make certain phenomena and portions of reality visible and understandable; many of these phenomena are not naturally accessible to the bare eye, and many of them are not even of visual nature.” [...] graphical displays can be either figurative or non-figurative. To understand figurative displays, think of a map as a scaled portrait of a geographi-cal area, or a manual that explains through illustrations how to use your new washing machine, [...] Other graphics that display abstract phenomena are non-figurative. In these, there is no mimetic correspondence between what is being represented and its representation. The relationship between those two entities is conventional, not natural.

By giving numbers a proper shape, by visually encoding them, the graphic has saved you time and energy that you would otherwise waste if you had to use a table that was not designed to aid your mind. The first and main goal of any graphic and visualization is to be a tool for your eyes and brain to perceive what lies beyond their natural reach.

Effective analytic designs entail turning thinking principles into seeing principles. So, if the thinking task is to understand causality, the task calls for a design principle: “Show causality.” If a thinking task is to answer a question and compare it with alternatives, the design principle is: “Show comparisons.” The point is that analytical designs are not to be decided on their convenience to the user or necessarily their readability or what psycholo-gists or decorators think about them; rather, design architectures should be decided on how the architecture assists analytical thinking about evidence. [Quoting Mark Zachary and Charlotte Thralls, “An Interview with Edward Tufte,” Technical Communica- tion Quarterly, 2004, 13(4), 447-462. Accessed Feb. 11, 2012 at http://www.edwardtufte.com/tufte/ s15427625tcq1304_5.pdf.]

Erich Schmidt, former CEO of Google, announced in a conference that between the beginning of time and 2003, humanity generated roughly five exabytes of data, whereas we now produce the same volume of bits every two days.

"The information explosion is so profoundly larger than anyone ever thought," said Schmidt. Five exabytes is more than 200,000 years of DVD-quality video.5

To be fair, not all that "information" is what you would call information in a colloquial conversation. Most of it is the product of automated processes and communications between computers, mobile phones, and other devices—nothing that a human brain can understand. But still.

It is true, as we just have seen, that function doesn’t necessarily determine form. But it is also true that the form of a technological object must depend on the tasks it should help with. This is one of the most important principles to re-member when dealing with infographics and visualizations: The form should be constrained by the functions of your presentation. [...] In general, the better defined the goals of an artifact, the narrower the variety of forms it can adopt.

The second theme is the common nature of infographics and information visualization. Some professionals and academics have erected a sharp distinction between the two disciplines. According to them, infographics present information by means of statistical charts, maps, and diagrams, while information visualiza-tion offers visual tools that an audience can use to explore and analyze data sets. That is, where infographics tell stories designed by communicators, information visualization helps readers discover stories by themselves. In the following pages, I take an unorthodox approach. Infographics and visu-alization exist on a continuum. [..] every infographic and every visualization has a presentation and an exploration component: they present, but they also facilitate the analysis of what they show, to different degrees.

Lamarck proposed a scientific theory called “inheritance of acquired character-istics.” To understand it, let’s consider giraffes, a descendant of ancient creatures that supposedly were similar to modern antelopes. How did the giraffe evolve its long neck?

According to Lamarckian logic, thousands and thousands of years ago, some an-telopes felt the need to feed on tree leaves beyond the reach of their mandibles. They began stretching their necks to get them. As a consequence, they were born with slightly longer necks than the previous generation. But this is like saying that if I start doing heavy bodybuilding today and become a clone of Sylvester Stallone, my kids will be born with steel muscles. To the followers of Lamarckism, form literally follows function. The former pushes the latter.

Thanks to Charles Darwin, though, we now know that evolution doesn’t work that way. Darwin’s On the Origin of Species was published in 1859 and offered an alternative to Lamarck’s hypothesis. The force that moves evolution forward is not the acquisition of characteristics and skills inherited by kin, but the natural selection of traits that help an organism survive in its environment. What Dar-win did was to invert Lamarck’s logic: Function doesn’t determine form. In fact, in many cases, the opposite is true. [..] This is called variation. [...] In other words, the need to reach higher every day (the function) didn’t force the development of longer necks (the form). Longer necks were the result of random genetic mutations that were nonrandomly filtered (that is, selected) by the envi-ronment. In nature, then, relationships between forms and functions are much more complex than what Sullivan thought.

Graphics, charts, and maps aren’t just tools to be seen, but to be read and scrutinized. The first goal of an infographic is not to be beautiful just for the sake of eye appeal, but, above all, to be understandable first, and beautiful after that; or to be beautiful thanks to its exquisite functionality. [...] As Ben Shneiderman wrote once, “The purpose of visualization is insight, not pictures.” Images are the vocabulary of a language. They are means, not ends. You will never hear a writing journalist say that her goal is to strive for a good literary style by using elegant sentences and sophisticated structures. Her style is just a tool to facilitate comprehension and to wake up emotions in readers’ minds so they’ll absorb difficult ideas with ease. Aesthetics do matter, but aesthetics without a solid backbone made of good content is just artifice. [...] Thinking of graphics as art leads many to put bells and whistles over substance and to confound infographics with mere illustrations.

It is tempting to propose rock-solid rules—if you want to show change through time, use a time-series chart; if you need to compare, use a bar chart; or to display correlation, use a scatter-plot— because some of these rules make good common sense. [...] But reality is complex, and hard-and-fast rules can transform sound advice into immovable law. Exceptions and nuances can arise with the particularities of each project. What is really important is to remember that no matter how creative and innovative you wish to be in your graphics and visualizations, the first thing you must do, before you put a finger on the computer keyboard, is ask yourself what users are likely to try to do with your tool.

In the 1970s, years before access to the Internet was universal, Richard Saul Wurman, then a professor of architecture in North Carolina, predicted that the oncoming information explosion would require the intervention of a new breed of professionals trained in organizing data and making sense of it. According to Wurman, the biggest challenge our species was about to face was to learn how to navigate the upcoming tsunami of bits that was cresting the horizon.

Wurman called these people information architects. Their discipline, information architecture, has been defined by others as:

• The structural design of shared information environments; • The combination of organization, labeling, search, and navigation systems within websites and intranets; • The art and science of shaping information products and experiences to support usability and findability; • An emerging discipline and community of practice focused on bringing principles of design and architecture to the digital landscape.

Wurman suggests that one of the main goals of information architecture is to help users avoid information anxiety, the “black hole between data and knowledge.”

[...]

without conscious effort, the brain always tries to close the distance between observed phenomena and knowledge or wisdom that can help us survive. This is what cognition means. The role of an information architect is to anticipate this process and generate order before people’s brains try to do it on their own.

The maxim “form follows function” was born in 1896 when the American archi-tect Louis Sullivan wrote an article titled, “The Tall Office Building Artistically Considered.” In it, Sullivan discussed the needs of the occupants of big office buildings, which had begun to proliferate at the end of the nineteenth century. [..] It is the pervading law of all things organic and inorganic, of all things physical and metaphysical, of all things human and all things superhuman, of all true manifestations of the head, of the heart, of the soul, that the life is recognizable in its expression, that form ever follows function. This is the law. [...] Those highlighted words were defining for twentieth-century architecture and had an enormous influence on contemporary masters, either because they em-braced them (the Bauhaus school), or because they rejected them or introduced their own nuances (Frank Lloyd Wright). Some of the most renowned ideas of luminaries like Le Corbusier, who defined a house as “a machine for living in,” connect directly to Sullivan.

individual information graphics are also technologies, means to fulfill purposes, devices whose aim is to help an audience complete certain tasks. This apparent no-brainer will have consequences later on. If you accept that a visualization is, above all, a tool, you are implicitly accepting that the discipline it belongs to is not just art, but functional art, something that achieves beauty not through the subjective, freely wandering self-expression of the painter or sculptor, but through the careful and restrained tinkering of the engineer.

Rather than serving as a means for the artist to express her inner world and feelings, an infographic or visualization strives for objectivity, precision and functionality, as well as beauty.

In other words: If we accept that an infographic is, at its core, a tool, what tasks is this one intended to help me with? Here is my personal list for the Brazilian defense graphic: 1. The graphic must present several variables—armed forces personnel, population to be defended, defense budget, and so forth—so that I have the proper information in front of me. 2. It should allow comparisons. At a glance, I should be able to tell which country has the biggest and the smallest army, is more or less populated, or invests more heavily or lightly in its military. 3. It should help me organize countries, from the biggest to the smallest, based on the variables and the comparisons. 4. It should make correlations evident to me. For instance, are population and size of defense forces directly and perfectly proportional?

Of those four possible tasks—present, compare, organize, correlate—the graphic accomplishes just one satisfactorily. It presents tons of variables and values. But it doesn’t show them in proportion to one another. This makes it impossible for readers to dig into the data. [...] From a functional standpoint, there’s little difference between this graphic and a simple table. The graphic may be prettier, but it still makes you work too hard to extract basic meanings.

Here’s the lesson I learned from this exercise: In just three or four hours of work, I completed a personal project that allowed me to see the evidence supporting Matt Ridley’s discussion on the evolution of fertility. His hypotheses seem to have some basis after all. But if you don’t present your data to readers so they can see it, read it, explore it, and analyze it, why would they trust you? This is a question many journalists, particularly those who write opinion columns, should ask themselves more often.

Another problem with Sullivan’s law is that the sentence “form follows function” indicates that the relationship between the two components is unidirectional. [..] The problem is that the world doesn’t work that way. A species doesn’t feel a need first (the function) and then develop an organ to fulfill it (the form). If you’ve ever had this kind of thought—some people still do—you’ve fallen prey to what is known as the Lamarckian Fallacy.

My curiosity ignited, I grabbed my Kindle and purchased the book. One minute later, it had finished downloading. For the rest of the day, I traded book writing for reading.