C & C p.14

1 – Describe how evidence and hypotheses are characteristics of science.

The scientific method involves making hypotheses (testable proposals) that seek to explain how natural phenomena occur. A hypothesis must be consistent with available evidence (data) that pertain to the phenomena being studied.

2 – How does a hypothesis differ from a theory? Give a concrete example of each.

A hypothesis is a testable question about an observation and may be stated in an “if…then” format. A theory is a model that is supported by data from many testable hypotheses and for which little, if any, opposing data have been found

C & Cp.14

3 – Describe the theory of evolution by means of natural selection.

The theory of evolution recognizes variation in all populations of organisms. The environment interacts with the population in such a way that individuals better adapted to the environment will produce more offspring than those who are less fit. Over time, this natural selection produces organisms well suited to their environment.

C & Cp. 14

4 – Describe how natural selection operates on species.Natural selection continuously culls individuals that are

less fit and results in species that are highly adapted to their environment.

5 – How do Lamarck’s theory and Darwin’s theory differ?Lamarck’s theory assumes that characteristics acquired

during an individual’s lifetime can be passed on to the next generation. In this view, inherited traits are based on “need.” Darwin’s theory was based on the interaction between inherited traits and their fitness in the environment.

RIp. 18

4 – How are hypotheses, observations, and experiments used in science?

Hypotheses are the questions being tested; observations gather data about the hypotheses and contribute to the design of experiments used to obtain answers to the questions.

6 – How did Darwin use the methods of science develop his theory?

Darwin made many observations during his voyage on the Beagle and after his return to England. He developed a hypothesis of how species change over time and examined his data to see whether or not they supported the hypothesis. Only after much study and deliberation did he conclude that evolution occurs and publish his results.

RIp. 18

7 – Why were Lamarck’s ideas rejected? On what assumptions were his ideas based?

Lamarck’s hypothesis was invalid because his basic assumption of inheritance of acquired characteristics was proved incorrect.

8 – Compare and contrast a hypothesis and a theory?

A hypothesis is an educated guess that tries to explain a natural phenomenon. A theory is a tested model that explains and organized hypotheses and experiments. Theories are supported by many data.

RIp. 18

9 – What is the relationship between natural selection and the environment?

The environment supplies conditions that determine which characteristics will enhance an individual’s chance of survival and reproduction

10- What are the characteristics of science, and how does it differ from pseudoscience?

Science is based on observations and experiments that are repeatable, verifiable, and refutable. Pseudoscience often is based on matters of faith that cannot be examined by observations and experiments or cannot be refuted.

UCp. 19

2- Some animals, such as the arctic fox and the ptarmigan (a bird), change the color of their fur or feathers from summer to winter. Relate these changes to natural selection.

Animals that change color to white during the winter are protected from predators by their color, and more will survive to reproduce than will animals with colors that stand out in the snow.

UCp. 19

3- Darwin stated that a struggle for existence-for adequate food, space, water, and so on-occurs in all species. Is this true for the human species as well? Give concrete examples to substantiate your answer.

Humans sometimes must struggle for food, space, and water just as other species must. Various examples of the struggle for existence, especially in developing countries, could be cited

UCp. 19

9- Imagine a long-legged wolf and a short-legged wolf. Relate the length of their legs to their ability to catch enough rabbits to feed their offspring. Would one wolf be more successful than the other in providing enough food for its offspring to survive? Would it be advantageous to have long legs?

Answers may varyLong-legged wolves may have an advantage over

short-legged wolves in a snowy environment because their legs will allow them to stand above the deep snow thus allowing the wolf to track down the rabbit more easily.