echnological progress, human curiosity, and the determination to explore moved people all over the world. This movement of people also meant that more and more people from different backgrounds would come together. The tasty history of food also includes what happens when cuisine and culture intertwine. The story of pizza reveals how food evolves over time because of the creativity of people. Tomatoes were brought to Europe from the Americas in the 16th century, but many Europeans believed them(=tomatoes) to be poisonous. Some poor people in Naples, Italy, in the late 18th century, maybe out of curiosity or necessity, began to use tomatoes as a bread topping. It tasted good, so tourists were attracted to the area to try this specialty. This was probably how pizza was born. Immigration in the 19th century brought pizza to the United States and Canada, increasing its popularity and sparking the creation of regional recipes like Chicago deep dish or New York pizza. Food gives strength, helps people fight, and evolves over time. It is also an intriguing way to learn about history. With the world becoming a smaller place and more and more varieties of foods being invented, it's no wonder that many people take vacations where the focus is on their stomachs. When they try a local dish for the first time, they feel an intimate connection with the unique history of that particular place. Food: what a wonderful, tasty way to learn about people and the history of the world.

Scientists today are able to accurately date fossils, the rock-bound remains of organisms from past geologic ages. When fossils are arranged along a timeline, scientists can see gradual changes from simple to more complex life forms. In some cases, evolution through various intermediate forms over millions of years can be detected and compared to the present state of an organism. For example, the earliest known species of horse lived some 60 million years ago and, according to the fossil record, was shorter than 20 inches (50 centimeters) high at the shoulders. Successive rock layers yield fossils of increasingly larger horse species, culminating in the horses of today. As size changed, so did other aspects of the horses' anatomy: teeth became adapted to eating grass, the bones of the lower leg fused, and multiple toes evolved into a single toe surrounded by a hoof.

Given the range of goals that can influence learning, it is not surprising that different models reflect different types and degrees of goal-based influence. Thagard and Millgram propose a broad distinction between learning which is explicitly goal-driven and that(=learning) which is goal-relevant. Goal-relevant processing is not explicitly directed by the goals of the reasoner, but results in outcomes that are nevertheless useful with respect to those goals. Thus, in goal-relevant processing, the desired learning may occur as a side effect of normal task-related processing. For example, a reasoner may have an implicit orientation to maintain an accurate model of the world around it. Goal-driven learning, in contrast, is driven by explicit learning goals of the reasoner; those goals influence or even determine the content of what is learned. As the reasoner's goals change, so does the learning that results.

In the spring and summer of 1837, fresh from his voyage on HMS Beagle, Charles Darwin began the grand synthesis of his research that was to become his celebrated theory of evolution. In mid-July, Darwin's thoughts were still scattered, his mood one of confused feeling. In a notebook, amid many tentative doodles and wild notes, he made a simple sketch that was to capture at a stroke the conceptual sweep of the theory slowly forming in his mind. The drawing was of an "irregularly branched" tree, intended to convey the genealogical history of plants and animals: a tree of life. As a metaphor it was brilliant, conveying the essential notion that life originated in the dim and distant past with a unique, spontaneous event. From this single common ancestor-the trunk of the tree-life diversified over time by successive branchings, with new species splitting away from old. The ends of the branches represent extinctions, like the dinosaurs and the dodo.

Health is a dynamic and complex state. It is a product of continuous interactions between an individual's genetic makeup, environmental conditions, and personal experiences. For example, an infant's immediate and long-term health is influenced by his or her mother's personal lifestyle practices during pregnancy: her diet; use or avoidance of alcohol, tobacco, and certain medications; routine prenatal care; and exposure to communicable illnesses or toxic stress. Mothers who fail to maintain a healthy lifestyle during pregnancy are more likely to give birth to infants who are born prematurely, have low birth weight, or experience a range of special challenges. These children also face a significantly greater risk of developing chronic health problems and early death. In contrast, a child who is born healthy, raised in a nurturing family, consumes a nutritious diet, lives in a safe environment, and has numerous opportunities for learning and recreation is more likely to enjoy a healthy life.