The Science of Marine Biology

Why do we study Marine Biology? Major Food Source Major Food Source Medicine Medicine Major source of oxygen Major source of oxygen Carbon dioxide “sink” (photosynthesis) Carbon dioxide “sink” (photosynthesis) Predict weather patterns Predict weather patterns Recreation Recreation Solve problems caused by marine organisms Solve problems caused by marine organisms Predict effects of human activities Predict effects of human activities

The HMS Challenger Expedition First major oceanographic expedition For three and a half years sailed around the globe collecting information and gathering samples. For three and a half years sailed around the globe collecting information and gathering samples. Set new standards for studying the ocean. Set new standards for studying the ocean. Systematic measurements were made and meticulous records were kept. Systematic measurements were made and meticulous records were kept. Laid the foundations of modern marine science Laid the foundations of modern marine science

Alvin 2Rc60 (Deep sea wave) 2Rc60 (Deep sea wave) 2Rc60 2Rc60

The Scientific Method A set of flexible procedures to answer a question or problem using direct observations A set of flexible procedures to answer a question or problem using direct observations Scientists may use tools to enhance their observations Scientists may use tools to enhance their observations Induction – specific observations lead to general conclusions Induction – specific observations lead to general conclusions Deduction – general principles are used to make specific predictions Deduction – general principles are used to make specific predictions Fig Fig. 1.19

Steps of the Scientific Method Observe a selected part of nature and then state the problem you wish to solve in the form of a testable hypothesis. Observe a selected part of nature and then state the problem you wish to solve in the form of a testable hypothesis. Formulate a hypothesis (“educated guess”). Often stated with the words if and then in order to devise an experiment to test it. Formulate a hypothesis (“educated guess”). Often stated with the words if and then in order to devise an experiment to test it. A hypothesis can be supported by experimental evidence or it may be proven false by experimental data. A hypothesis can be supported by experimental evidence or it may be proven false by experimental data.

The Scientific Method Experiment a. In a controlled experiment two groups are tested: one that is exposed to the variable and one that is not. (Fig. 1-20) b. Variable – what you are changing or measuring 1. independent variable – what you are changing changing 2. dependent variable – what you are 2. dependent variable – what you are measuring measuring

The Scientific Method Make observations and record results Make observations and record results Analysis/Conclusion – do results support or disprove the hypothesis Analysis/Conclusion – do results support or disprove the hypothesis Publish results – other scientists can repeat and see of they get the same results Publish results – other scientists can repeat and see of they get the same results

A bar graph is used to compare data and show relationships at a glance.

A line graph shows the relationships between variables (i.e. – independent/dependent)

Scientific Theories A theory is a statement made based on a broad range of phenomenon A theory is a statement made based on a broad range of phenomenon Example – Theory of Evolution – species evolve over time with natural selection being the driving force. Example – Theory of Evolution – species evolve over time with natural selection being the driving force. Theory is supported by; fossil record, comparative anatomy, embryology, DNA analysis Theory is supported by; fossil record, comparative anatomy, embryology, DNA analysis

Scientific Laws A statement that is true – usually based on a mathematical equation A statement that is true – usually based on a mathematical equation Charles Law – V 2 = V 1 T 2 Charles Law – V 2 = V 1 T 2 T 1 T 1 (volume of gas varies directly with temp.) (volume of gas varies directly with temp.) Boyles Law - V 2 = V 1 P 1 Boyles Law - V 2 = V 1 P 1 P 2 P 2 (pressure is inversely proportional to volume (pressure is inversely proportional to volume

Bar Graphs and Line Graphs Using the information in the following slide construct one bar graph and one line graph in your lab book. Using the information in the following slide construct one bar graph and one line graph in your lab book. Copy the data table into your lab book. Copy the data table into your lab book. What can you conclude from the information in your graphs? What can you conclude from the information in your graphs?

Average speed of snails at different temperatures (cm/min) Trial 13 0 C 18 0 C 24 0 C 30 0 C Total Avg. Speed