1. Chapter 1 Invitation to Biology (Sections 1.5 - 1.9)

2. 1.5 Organizing Species Information
Each type of organism has a unique, two-part name
The first part is the genus name
When combined with the specific epithet, it designates a particular species
Linnaean taxonomy (Carolus Linnaeus) sorts all species into taxa on the basis of shared traits

3. Key Terms species A type of organism genus
A group of species that share a unique set of traits; also the first part of a species name
specific epithet
Second part of a species name

4. Key Terms taxonomy The science of naming and classifying species
taxon (taxa)
A grouping of organisms

5. Linnaean Classification

6. DOMAIN Eukarya KINGDOM Plantae PHYLUM Magnoliophyta CLASS
Magnoliopsida
ORDER
Apiales
FAMILY
Apiaceae
GENUS
Daucus
SPECIES
Figure 1.7 Linnaean classification of five species that are related at different levels. Each species has been assigned to ever more inclusive groups, or taxa: in this case, from genus to domain
carota
COMMON NAME
carrot
Fig. 1.7a, p. 10

7. DOMAIN Eukarya KINGDOM Plantae PHYLUM Magnoliophyta CLASS
Magnoliopsida
ORDER
Rosales
FAMILY
Cannabaceae
GENUS
Cannabis
Figure 1.7 Linnaean classification of five species that are related at different levels. Each species has been assigned to ever more inclusive groups, or taxa: in this case, from genus to domain
SPECIES
sativa
COMMON NAME
marijuana
Fig. 1.7b, p. 10

8. DOMAIN Eukarya KINGDOM Plantae PHYLUM Magnoliophyta CLASS
Magnoliopsida
ORDER
Rosales
FAMILY
Rosaceae
GENUS
Malus
Figure 1.7 Linnaean classification of five species that are related at different levels. Each species has been assigned to ever more inclusive groups, or taxa: in this case, from genus to domain
SPECIES
domesticus
COMMON NAME
apple
Fig. 1.7c, p. 10

9. DOMAIN Eukarya KINGDOM Plantae PHYLUM Magnoliophyta CLASS
Magnoliopsida
ORDER
Rosales
FAMILY
Rosaceae
GENUS
Rosa
Figure 1.7 Linnaean classification of five species that are related at different levels. Each species has been assigned to ever more inclusive groups, or taxa: in this case, from genus to domain
SPECIES
acicularis
COMMON NAME
arctic rose
Fig. 1.7d, p. 10

10. DOMAIN Eukarya KINGDOM Plantae PHYLUM Magnoliophyta CLASS
Magnoliopsida
ORDER
Rosales
FAMILY
Rosaceae
GENUS
Rosa
Figure 1.7 Linnaean classification of five species that are related at different levels. Each species has been assigned to ever more inclusive groups, or taxa: in this case, from genus to domain
SPECIES
canina
COMMON NAME
dog rose
Fig. 1.7e, p. 10

11. 3 Domains or 6 Kingdoms

12. Bacteria Archaea Eukarya
Figure 1.8 Two ways to see the big picture of life. Lines in such diagrams indicate evolutionary connections. Compare Figure 1.6.
A three-domain system sorts all life into three
domains: Bacteria, Archaea, and Eukarya. The
Eukarya domain includes all eukaryotes.
Fig. 1.8a, p. 11

13. Bacteria Archaea Protists Plants Fungi Animals
Figure 1.8 Two ways to see the big picture of life. Lines in such diagrams indicate evolutionary connections. Compare Figure 1.6.
A six-kingdom classification system in which all eukaryotes have been sorted into one of four kindgoms: protists, plants, fungi, and animals. The protist kingdom includes the most ancient multi-celled and all single-celled eukaryotes.
Fig. 1.8b, p. 11

14. The Three Domains

15. A Rose by Any Other Name…
Individuals of a species share a unique set of traits
Morphological traits
Physiological traits
Behavioral traits
Species can be hard to distinguish
“biological species concept”

16. Four Butterflies, Two Species
Figure 1.9 Four butterflies, two species: Which are which? Two forms of the species Heliconius melpomene are on the top row; two of H. erato are on the bottom row. These two species never cross-breed. Their alternate but similar patterns of coloration evolved as a shared warning signal to local birds that these butterflies taste terrible.

17. 1.6 The Nature of Science
Critical thinking is judging the quality of information before accepting it
Scientists make and test potentially falsifiable predictions about how the natural world works
Science addresses only what is observable

18. (1) Thinking About Thinking
Critical thinking, the self-directed act of judging the quality of information as one learns, is an important part of science
critical thinking
Judging information before accepting it
science
Systematic study of the observable world

19. (2) How Science Works
Generally, a researcher observes something in nature, uses inductive reasoning to form a hypothesis for it, then uses deductive reasoning to make a prediction about what might occur if the hypothesis is not wrong

20. Key Terms hypothesis Testable explanation of a natural phenomenon
inductive reasoning
Drawing a conclusion based on observation
deductive reasoning
Using a general idea to make a conclusion about a specific case

21. (2) How Science Works (cont.)
Predictions are tested with observations, experiments, or both
Experiments typically are performed on an experimental group as compared with a control group, and sometimes on models

22. Key Terms
prediction
Statement, based on a hypothesis, about a condition that should exist if the hypothesis is correct
experiment
A test designed to support or falsify a prediction
model
Analogous system used for testing hypotheses

23. Key Terms experimental group
In an experiment, the group of individuals who are exposed to an independent variable
control group
In an experiment, the group of individuals who are not exposed to the independent variable that is being tested

24. (2) How Science Works (cont.)
Conclusions are drawn from experimental results, or data
A hypothesis that is not consistent with data is modified
Making, testing, and evaluating hypotheses is the scientific method

25. Key Terms data Experimental results scientific method
Making, testing, and evaluating hypotheses

26. The Scientific Method

27. (2) How Science Works (cont.)
Biological systems are usually influenced by many interacting variables
An independent variable influences a dependent variable

28. Key Terms
variable
In an experiment, a characteristic or event that differs among individuals or over time
independent variable
Variable that is controlled by an experimenter in order to explore its relationship to a dependent variable
dependent variable
In an experiment, the variable that is presumably affected by the independent variable that is being tested

29. Research in Field and Lab
Figure 1.10 Scientists doing research. From left to right, surveying wildlife in New Guinea; sequencing the human genome; looking for fungi in atmospheric dust collected in Cape Verde; improving the efficiency of biofuel production from agricultural wastes; studying the benefits of weedy buffer zones on farms.

30. Key Concepts The Nature of Science
Science helps us be objective about our observations by addressing only the observable
It involves making, testing, and evaluating hypotheses

31. 1.7 Examples of Experiments
Researchers use experiments to unravel complex natural processes by changing one variable at a time
Experiments are designed in a consistent way
Researchers change an independent variable, then observe effects of change on a dependent variable
Helps determine cause-and-effect relationship in a complex natural system

32. Potato Chips and Stomachaches
An experiment to determine if the artificial fat Olestra causes stomach cramps

33. Potato Chips and Stomachaches
Hypothesis
Olestra® causes intestinal cramps.
Prediction B
People who eat potato chips made with Olestra will be more likely to get intestinal cramps than those who eat potato chips made without Olestra.
Experiment C
Eats regular potato chips
Control Group
Eats Olestra potato chips
Experimental Group
Results D
93 of 529 people get cramps later (17.6%)
89 of 563 people get cramps later (15.8%)
Figure 1.11 The steps in a scientific experiment to determine if Olestra causes cramps. A report of this study was published in the Journal of the American Medical Association in January 1998.
Conclusion E
Percentages are about equal. People who eat potato chips made with Olestra are just as likely to get intestinal cramps as those who eat potato chips made without Olestra. These results do not support the hypothesis.
Stepped Art
Fig. 1.11, p. 14

34. Butterflies and Birds
How do peacock butterflies defend themselves against predatory birds?
Observation:
1. Wing-flicking shows wing spots
2. Hissing and clicking sounds
Predictions:
1. Wing spots scare predators
2. Sounds deter birds

35. Butterflies and Birds

36. Figure 1. 12 Peacock butterfly defenses against predatory birds
Figure 1.12 Peacock butterfly defenses against predatory birds. A With wings folded, a resting peacock butterfly looks a bit like a dead leaf. B When a bird approaches, the butterfly repeatedly flicks its wings open and closed, a behavior that exposes brilliant spots and produces hissing and clicking sounds. Researchers tested whether the butterfly’s behavior deters blue tits C. They painted over the spots of some butterflies, cut the sound-making part of the wings on other butterflies, and did both to a third group; then the biologists exposed each butterfly to a hungry bird. The results, listed in Table 1.3, support the hypotheses that peacock butterfly spots and sounds can deter predatory birds.
Fig. 1.12a, p. 15

37. Figure 1. 12 Peacock butterfly defenses against predatory birds
Figure 1.12 Peacock butterfly defenses against predatory birds. A With wings folded, a resting peacock butterfly looks a bit like a dead leaf. B When a bird approaches, the butterfly repeatedly flicks its wings open and closed, a behavior that exposes brilliant spots and produces hissing and clicking sounds. Researchers tested whether the butterfly’s behavior deters blue tits C. They painted over the spots of some butterflies, cut the sound-making part of the wings on other butterflies, and did both to a third group; then the biologists exposed each butterfly to a hungry bird. The results, listed in Table 1.3, support the hypotheses that peacock butterfly spots and sounds can deter predatory birds.
Fig. 1.12b, p. 15

38. Figure 1. 12 Peacock butterfly defenses against predatory birds
Figure 1.12 Peacock butterfly defenses against predatory birds. A With wings folded, a resting peacock butterfly looks a bit like a dead leaf. B When a bird approaches, the butterfly repeatedly flicks its wings open and closed, a behavior that exposes brilliant spots and produces hissing and clicking sounds. Researchers tested whether the butterfly’s behavior deters blue tits C. They painted over the spots of some butterflies, cut the sound-making part of the wings on other butterflies, and did both to a third group; then the biologists exposed each butterfly to a hungry bird. The results, listed in Table 1.3, support the hypotheses that peacock butterfly spots and sounds can deter predatory birds.
Fig. 1.12c, p. 15

39. Results of Butterfly Experiment

40. 1.8 Asking Useful Questions
Small sample size increases potential for sampling error in experimental results – a subset may be tested that is not representative of the whole
Researchers design experiments to minimize bias, and use probability rules to check statistical significance of results
Science is self-correcting because scientists check and test one another’s ideas

41. Key Terms sampling error
Difference between results derived from testing an entire group of events or individuals, and results derived from testing a subset of the group
probability
The chance that a particular outcome of an event will occur; depends on the total number of outcomes possible
statistically significant
Refers to a result that is statistically unlikely to have occurred by chance

42. Sampling Error Jelly beans in a jar: Sample: Assumption:
120 green (30%)
280 black (70%)
Sample:
1 green jelly bean
Assumption:
all jelly beans are green
Natalie, blindfolded, randomly plucks a jelly bean from a jar. There are 120 green and 280 black jelly beans in that jar, so 30 percent of the jelly beans in the jar are green, and 70 percent are black. 1

43. Sampling Error Sample: 50 jelly beans Assumption:
10 green
40 black
Assumption:
20% green
80% black
Larger sample is closer to actual ratio
Still blindfolded, Natalie randomly picks out 50 jelly beans from the jar. She ends up picking out 10 green and 40 black ones. 3

44. Error and Probability
Error bars indicate sampling error – the range of values above and below average in the sample
Figure 1.14 Example of error bars in a graph. This particular graph was adapted from the peacock butterfly research described in Section 1.7. The researchers recorded the number of times each butterfly flicked its wings in response to an attack by a bird. The squares represent average frequency of wing flicking for each sample set of butterflies. The error bars that extend above and below the squares indicate the range of values—the sampling error.

45. Bothering With Bias
Experimenters risk interpreting results in terms of what they want to find out
Experiments should be designed to yield data that can be counted or otherwise measured objectively

46. Key Concepts Experiments and Research
Researchers carefully design and carry out experiments in order to unravel cause-and effect relationships in complex natural systems

47. 1.9 Philosophy of Science
Science helps us be objective about our observations because it is only concerned with testable ideas about observable aspects of nature
Opinion and belief have value in human culture, but they are not addressed by science

48. About the Word “Theory”
A scientific theory is a longstanding hypothesis that is useful for making predictions about other phenomena – it is our best way of describing reality
A law of nature describes something that occurs without fail, but for which we do not have a complete scientific explanation

49. Key Terms scientific theory
Hypothesis that has not been disproven after many years of rigorous testing
law of nature
Generalization that describes a consistent natural phenomenon for which there is incomplete scientific explanation

50. Some Scientific Theories

51. Limits of Science
Subjective values (moral, aesthetic or philosophical) can’t be tested by the scientific method
Science doesn’t address the supernatural, or anything beyond nature

52. The Secret Life of Earth (revisited)
We have discovered only a small fraction of the species that share Earth with us
Mouse lemur discovered in 2005