Join scientists as they solve a mystery :Join scientists as they solve a mystery


Ohio Academic Content Standards :Ohio Academic Content Standards Scientific Inquiry Doing Scientific Inquiry Distinguish between observations and inferences given a scientific situation. 6. Draw logical conclusions based on scientific knowledge and evidence from investigations.


Ohio’s Academic Content Standards :Ohio’s Academic Content Standards Scientific Ways of Knowing Scientific Theories 5. Justify that scientific theories are explana- tions of large bodies of information and/or observations that withstand repeated testing.


Scientific Method :Scientific Method The basic steps in the scientific method are:          1.   Stating the problem (often in the form of a question)          2.  Gathering information on the problem          3.   Forming a hypothesis (your informed guess as to what is the answer) 4. Performing experiments to test the hypothesis      5.  Recording and analyzing data          6.   Stating a conclusion (the answer to the question) 7. Repeating the work


The Mystery :The Mystery Nine dead bottlenose dolphin calves were found on the beaches in Virginia in 1996 and 1997.


Bottlenose dolphins :Bottlenose dolphins Each year bottlenose dolphins are seen in Virginia between May and October.


The Mystery Deepens :The Mystery Deepens Scottish researchers found a large number of porpoise deaths in northeast Scotland.


Scientists in the USA and Scotland work together :Scientists in the USA and Scotland work together What do the scientists do first? State the problem (often in the form of a question) How would you state the problem?


What do you think happened to the dolphins and porpoises? :What do you think happened to the dolphins and porpoises? Let’s brainstorm some possible ideas in class.


What did the scientists do next? :What did the scientists do next? They gathered information on the problem. How do you think the scientists gathered the information?


Scientists gather information :Scientists gather information The U.S. dolphin remains were examined at the Virginia Marine Science Museum, the University of North Carolina at Wilmington, and the Armed Forces Institute of Pathology in Washington, D.C. The scientists found the calves were less than 158 centimeters in length (5.18 feet), likely less than one year old and still needing milk from their mothers.


The injuries :The injuries The scientists found severe injuries inside the calves including many broken bones, bad internal bleeding and bruises around the heads and thoraxes, or upper parts of the bodies. Only three calves had any injuries on the outside of their bodies. The porpoises had similar damage to their bodies.


What do the scientists do next? :What do the scientists do next? Form a hypothesis (your informed guess as to what is the answer) What is your hypothesis?


Could the scientists perform experiments in this case? :Could the scientists perform experiments in this case? The scientists had to study the evidence to see if the calves and porpoises died because of: - predators - boats - fisheries - injuries due to rough surfs - injuries from blasts (naval base in Virginia and oil rigs in Scotland)


Record data :Record data The scientists took careful note of the information they obtained. The scientists ruled out death by predator, boats, fisheries, rough surfs or blasts. Predators were ruled out because few of the animals had any injuries to the outsides of their bodies. There were no shark bites.


Why scientists ruled out boats, fisheries, rough surfs and blasts :Why scientists ruled out boats, fisheries, rough surfs and blasts Boats could hurt the animals, however the injuries would not be directed at the head and upper body areas. The injuries would be sharp also. The injuries that fisheries and rough surfs cause do not match the injuries on the dolphins. A blast in the ocean would have hurt other marine animals, not just the calves.


Now comes the conclusion :Now comes the conclusion What do you think happened?


One more piece of information :One more piece of information Skin scrapes and a bite gash found on three calves and some porpoises match the teeth marks of adult bottlenose dolphins. Now what is your conclusion?


Film confirmation :Film confirmation Scientists located video that showed bottlenose dolphins violently ramming porpoises high in the air. The ramming causes internal injuries that kill the porpoises.


Why does this happen? :Why does this happen? Why do you think this happens? Scientists suspect males kill calves so a female will have their offspring. Lions do this also. Scientists also suspect the attacks on porpoises help prepare dolphins to attack the bottlenose calves.


Observations and inferences :Observations and inferences Please list the observations in this scientific investigation. How do you know they are observations? What are the inferences in this scientific investigation? How do you know they are inferences?


Sources :Sources 1. Science News, Vol. 154, No. 3, July 18, 1998, p. 36. 2. Dunn, D.G., Barco, S.G., Pabst, D. A, McLellan, W. A. Evidence for infanticide in bottlenose dolphins of the western North Atlantic. Journal of Wildlife Diseases, 38(3), 2002, PP. 505-510.


Sources continued :Sources continued Blundell, N. (2008, Jan. 25). Killer dolphins baffle marine experts. The Telegraph (U.K.) Broad, W.J. (1999, July 6). Evidence puts dolphins in new light, as killers. The New York Times. 5. Science News, Vol. 154, (3), July 18, 1998.