a. Aesthetic wonder is the joy of encountering remarkable and beautiful things (Figure 1.2).

b. Scientific wonder moves people to ask questions in an effort to understand observed phenomena.

a. According to the best physical evidence, the universe originated at least 13 billion years ago (Figure 1.3).

b. The universe has been evolving from the beginning of time, and evolution does not imply progress, only persistent change (Figure 1.4).

c. Our existence depends on the accident that, as our own sun formed, much of the heavy matter was left outside the sun and condensed into planets, some with metal cores of iron and nickel and rocky surfaces with substantial amounts of water (Figure 1.5).

d. Only large, complex carbon-based molecules can make the highly ordered structures of organisms.

e. The first small carbon-based molecules combined into larger molecules, which eventually associated to make the first simple cells (Figure 1.7).

f. Our knowledge of life, climate, and geological events in the past comes from rocks containing fossils, the mineralized remnants of organisms or their traces, such as footprints and impressions (Figure 1.8).

g. Some of the most ancient rocks show remnants of small, simple, single-celled organisms quite similar to certain bacteria living today (Figure 1.9).

a. Science in general may be best defined by listing some of its principal features.

b. A hypothesis is an educated guess, a conjecture offered to explain some phenomenon.

c. In science, a theory is a logical structure of ideas that not only explains a few observations but also makes sense of a large body of knowledge and explains how some part of the world operates (Figure 1.10).

a. A story is considered pseudoscience if people continue to believe it in the absence of any sound evidence or in the face of strong counter evidence.

b. Pseudoscience often violates an important scientific guide, the Principle of Parsimony, which says that one ought to prefer the simplest satisfactory explanation.

c. Unscientific beliefs imitate science, but do it badly with too strong a will to believe and too little objective testing and skepticism.

d. Nonscientific work is human activity that has little or nothing to do with science and is done for different reasons (e.g. fine arts, sports).

a. Organisms are genetic systems.

b. Organisms live in ecosystems.

c. Biological evolution, operating primarily through natural selection, is responsible for the variety of organisms we observe.

d. Organisms function through molecular interactions.

a. There are at least three good kinds of biological explanations:

b. Teleological explanations try to explain events in terms of the purposes they serve.

c. Teleonomic explanations address the function served and use evolutionary history to explain how a process serving that function could appear.

a. Reductionism maintains that the more complex explanations of chemistry and biology can be reduced to physical explanations, and that every chemical statement could be translated into the sum of several physical statements.

b. Emergent properties are properties of a whole structure that go beyond those of its parts.

a. Metabolism is a complicated series of chemical processes in living organisms that take in raw materials from the environment and shape them into structured molecules (Figure 1.11).

b. If "life" means anything at all, it is the sum of all the processes and ways of behaving.

a. By picking up any newspaper, a casual observer can see that biology is a very busy area of modern science (Figure 1.12).

b. Some would argue that the best reason to study biology is simply to satisfy the human sense of curiosity and wonder about the world.

c. In addition to satisfying curiosity, the study of biology can lead to interesting, productive careers in areas such as: