Some tips for success! Come to class!!! Prepare for and be engaged in class (find your daily bio hour!) Study often (daily bio hour!) Master the vocabulary (daily bio hour!) Practice active learning Always ask: how? why? Try to find exceptions Make it relevant to your own life Put topics together into the big picture Make connections to build knowledge

BIOLOGY is the study of life

Living things… are complex & organized respond to stimuli Maintain homeostasis process energy grow & reproduce have deoxyribonucleic acid (DNA) have the capacity to change over time

A question from your final exam: Why do some animals engage in filial cannibalism? What do we know? How do we know? Why do we think so? What is the evidence?

What is Science?

We do science every day That’s kind of weird. I wonder why that happens. How can I figure out what’s going on? I wonder what will happen if I do this. Does it do this every time?

We do science every day How can lose weight? Is this prescription right for me? How can I manage my illness? Should I buy a hummer or a hybrid? Should I recycle these cans? What should I plant in my garden? Is this the right pet for me?

Scientific Thought Opinion Hypothesis These frogs are cute These frogs are engaged in competition for a place to live

Finding out Observation Questions Systematic process Evidence Tanning sharks

Finding out Observation Questions Systematic process Evidence Not the right answer, but the search for the best supported answer Tanning sharks 10

Observation Conclusion Experiment or Prediction Hypothesis Question Two frogs are observed together Why are these frogs hanging out together? The frogs are together because they both want the territory. Figure 1-4b The scientific method (b) An example from everyday life. IF the hypothesis is correct and the frogs are competing for territory, THEN they will fight and/or one will leave. Observe the frogs to see if they fight The territoriality hypothesis is supported. Figure 1-4b Biology: Life on Earth 8/e ©2008 Pearson Prentice Hall, Inc.

Observation Conclusion Experiment or Prediction Hypothesis Question Sometimes mother prairie dogs eat their own young Why do prairie dogs engage in filial cannibalism? What hypothesis would you make about filial cannibalism? Figure 1-4b The scientific method (b) An example from everyday life. Figure 1-4b Biology: Life on Earth 8/e ©2008 Pearson Prentice Hall, Inc.

A hypothesis is a tentative explanation for observed phenomenon A hypothesis is a tentative explanation for observed phenomenon. (Not just a summary of observations) Must be testable Must be falsifiable Must be detailed enough for specific predictions to be made. Generally based on observations Avoid terms such as “good” or “best” because they are vague “Ghosts did it” “Frogs like water”

When a hypothesis has evidence to back it up it is SUPPORTED never, proven.

When enough evidence (like, a lot of evidence) supports a theory, it becomes upgraded to a Theory! Yay! This involves repeated testing under a variety of conditions exploration of alternate explanations Evaluation and acceptance of many scientists within the scientific community

THEORIES Best explanation BASED ON EVIDENCE Cannot be “proven”

Here’s some terrible advice..

Make a Hypothesis: Is a daphnia a living thing? To make your hypothesis, write down what you think life is Discuss it with a small group What do you agree about? What are your differences? What are you unsure of? Edit your definition (if you want) Examine your daphnia to determine if it meets the criteria you established

Hypotheses that determine a cause-effect relationship… All of the variables and outcomes in the hypothesis should be worded in a precise way. Independent Variable: the presumed “cause”. It is purposefully altered in an experiment. Dependent Variable: the presumed “effect”. It is measured in an experiment

Controlled Experiments Control group- the group that is unaltered in an experiment. Used to make sure that no other variables are affected in the experiment Controlled variables- other variables that need to remain constant in an experiment. Temperature, light, pH, salinity, etc. If you are testing the effect of how various concentrations of vinegar affect the hachability of brine shrimp, the control group would not have any vinegar. Other controlled variables would include water source, temperature, pH, salinity, light, time, etc.

Hypotheses: The Good, the Bad, and the Ugly Working with your table partner, read each hypotheses on your worksheet. Discuss and evaluate 1-2 based on the criteria of a good hypothesis. If you do not consider it “good”, rewrite it. If it is so bad that you cannot rewrite it, it is in the ugly category.

The Theory of Evolution is Biology’s central organizing principle Change over time Large body of evidence Informs modern problems

There are still questions to be answered! Viruses

Systematics Developing, evaluating classification systems Building phylogenies that represent evolutionary relationships Naming species

Carolus Linnaeus (1707-1778) Laid the groundwork for the modern classification system Placed organisms into hierarchical categories based on their resemblance to other organisms Introduced the scientific name composed of genus and species

We know that science is based on evidence, so… what evidence can we use to classify organisms? Whale shark Whale vs.