The fruit ripening process brings about the softening of cell walls, sweetening and the production of chemicals that give colour and flavour. The process is induced by the production of a plant hormone called ethylene. The problem for growers and retailers is that ripening is followed sometimes quite rapidly by deterioration and decay and the product becomes worthless. Tomatoes and other fruits are, therefore, usually picked and transported when they are unripe. In some countries they are then sprayed with ethylene before sale to the consumer to induce ripening. However, fruit picked before it is ripe has less flavour than fruit picked ripe from the plant. Biotechnologists therefore saw an opportunity in delaying the ripening and softening process in fruit. If ripening could be slowed down by interfering with ethylene production or with the processes that respond to ethylene, fruit could be left on the plant until it was ripe and full of flavour but would still be in good condition when it arrived at the supermarket shelf.

The growing complexity of the social dynamics determining food choices makes the job of marketers and advertisers increasingly more difficult. In the past, mass production allowed for accessibility and afford ability of products, as well as their wide distribution, and was accepted as a sign of progress. Nowadays it is increasingly replaced by the fragmentation of consumers among smaller and smaller segments that are supposed to reflect personal preferences. Everybody feels different and special and expects products serving his or her inclinations. In reality, these supposedly individual preferences end up overlapping with emerging, temporary, always changing, almost tribal formations solidifying around cultural sensibilities, social identifications, political sensibilities, and dietary and health concerns. Personal stories connect with larger narratives to generate new identities. These consumer communities go beyond national boundaries, feeding on global and widely shared repositories of ideas, images, and practices.

Mosquitoes can carry and transmit many disease-causing microbes to humans. They also have microbiota. Again, knowledge of this has been exploited to try to thwart mosquitoes' capacity to transmit infections to humans. Many insects carry Wolbachia bacteria normally. In nature, Aedes aegypti, the mosquito that transmits dengue, chikungunya, Zika, and other viruses, are not normally infected with Wolbachia; however, they can survive when infected with Wolbachia. It turns out, however, that if infected with Wolbachia, they may be unable to transmit certain viruses like dengue and chikungunya and other viruses that cause disease. Researchers are now studying whether they can use this information to prevent transmission. They are rearing mosquitoes, intentionally infecting male mosquitoes with Wolbachia, and releasing them into the wild. Male mosquitoes do not take blood meals and do not transmit infections. The released male mosquitoes' mate with local female mosquitoes and Wolbachia is passed to the next generation via eggs. The presence of Wolbachia infection in the next generation of mosquitoes inhibits viruses such as dengue. Use of this technique in one area of Australia has been extremely effective in interrupting dengue transmission. Tests are also underway in other areas.

Generally speaking, a model is a simplified representation of reality created to serve a purpose. It is simplified based on some assumptions about what is and is not important for the specific purpose, or sometimes based on constraints on information or tractability. For example, a map is a model of the physical world. It abstracts away the information that the mapmaker deemed irrelevant for its purpose. It preserves, and sometimes further simplifies, the relevant information. For example, a road map keeps and highlights the roads, their basic topology, their relationships to places one would want to travel, and other relevant information. Various professions have well-known model types: an architectural blueprint, an engineering prototype, and so on. Each of these abstracts away details that are not relevant to their main purpose and keeps those that are.

Ancient Greek democracy allowed the public to participate directly in the affairs of government by choosing policies and making governing decisions. In this sense, the people were the state. In contrast, the Roman Empire laid out the concept of republicanism, which emphasized the separation of powers within a state and the representation of the public through elected officials. Thus, while Greece gives us the idea of popular sovereignty, it is from Rome that we derive the notion of legislative law and the senate. In their earliest forms, neither Greek democracy nor Roman republicanism would be defined as liberal democracies by today's standards. Both emphasized certain democratic elements but restricted them in fundamental ways. As political rights and institutions have expanded over the centuries, republicanism and democracy have become intertwined to produce the modern liberal democratic regime we know today.

Today's technology offers alternatives to the traditional approach in education. Take one feature of the traditional approach, the fact that teaching in a classroom is unavoidably one size fits all. Teachers cannot tailor their material to the specific needs of every student, so in fact the education provided tends to be one size fits none. This is particularly frustrating because tailored tuition is known to be very effective: an average student who receives one-to-one tuition will tend to outperform 98 percent of ordinary students in a traditional classroom. In education research, this is known as the two sigma problem ― two sigma, because that average student is now almost two standard deviations (in mathematical notation, 2σ) ahead of ordinary students in achievement, and a problem since an intensive tutoring system like this, although it can achieve impressive outcomes, is prohibitively expensive. Adaptive or personalized learning systems promise to solve this problem, tailoring what is taught to each student but at a far lower cost than the human alternative.

Imagine a population that consists of solid citizens and shirkers. The solid citizens produce a public good that is available to everybody, including themselves. For purposes of the example, let's say that the public good can be produced at no cost to the solid citizens. Not only do they share the richness, but they lose nothing by creating it. Even so, the solid citizens will not be favored by natural selection because the solid citizens and shirkers differ in their survival or reproduction, so raising or lowering the fitness of everyone in the population has no effect. If, as seems likely, the public good is costly to produce, the solid citizens will go extinct, even if they share the benefits, because their private cost reduces their fitness relative to the shirkers. Behaviors that are for the good of the group are at best neutral (if the public good is cost-free) and at worst maladaptive (if there is any cost associated with producing the public good).

Many of the white colonialists openly despised New Guineans as primitive. Even the least able of New Guinea's white masters, as they were still called in 1972, enjoyed a far higher standard of living than New Guineans. We all know that history has proceeded very differently for peoples from different parts of the globe. In the 13,000 years since the end of the last Ice Age, some parts of the world developed literate industrial societies (with metal tools) other parts developed nonliterate farming societies, and still others developed societies of hunter-gatherers or herders. Those historic inequalities have cast long shadows on the modern world, because the literate societies with metal tools have conquered or exterminated the other societies. While those differences constitute the most basic fact of world history, the reasons for them remain uncertain and controversial.

Successful integration of an educational technology is marked by that technology being regarded by users as an unobtrusive facilitator of learning, instruction, or performance. When the focus shifts from the technology being used to the educational purpose that technology serves, then that technology is becoming a comfortable and trusted element and can be regarded as being successfully integrated. Few people give a second thought to the use of a ball-point pen although the mechanisms involved vary ― some use a twist mechanism and some use a push button on top, and there are other variations as well. Personal computers have reached a similar level of familiarity for a great many users, but certainly not for all. New and emerging technologies often introduce both fascination and frustration with users. As long as the user's focus is on the technology itself rather than its use in promoting learning, instruction, or performance, then one ought not to conclude that the technology has been successfully integrated ― at least for that user.