BI 151 – Journal Entry 1

The Diversity of Life
What's Your Hypothesis?

Now it's time for you to try to answer the central question of the course. In your personal journal, write your hypothesis about the history and diversity of life. This hypothesis should contain answers to the following questions:

1.What were the first living things on Earth?

2.Are all species that ever lived still around now?

3.Have any species changed at all?

4.Are any species related to each other (do they share a common ancestor?) Which ones?

Write a hypothesis about the history and diversity of life. The hypothesis should be a narrative that explains your ideas.

Explain your OWN ideas about it - what you really think. Be sure that what you put down is a testable hypothesis. That is, limit yourself to things in the physical, observable world, but remember that past events leave traces in the present, so hypotheses about the past can be falsifiable. For instance, if part of your hypothesis is that all birds were put on Earth by aliens last Tuesday, that's falsifiable -- one could look for feathers in old pillows, for instance, which shouldn't be there if the hypothesis is correct.

What about God? Is God part of a scientific hypothesis? Remember that a hypothesis must be falsifiable -- that is, it has to make predictions, and if those predictions were wrong, that would demonstrate that the hypothesis was false. We'll talk more about falsifiability as we go along.

Also, be sure to do this based on your personal views as they stand now -- don't try to figure out what some textbook authors' views are, or what the instructors' ideas are, etc. Grading of this assignment is based on how well you express your ideas, not whether you have the same answer as someone else would.

While thinking about these questions, consider the wide variety of organisms that live on earth, including specifically:








E. coli



Homo sapiens

land snail


maple tree

marine worm



praying mantis




You must specifically talk about each of these organisms in your response to question 4. Be sure you don't ignore certain organisms or whole groups such as plants, fungi, bacteria, invertebrate animals, etc., just because you like things that are cute and furry.

Please note that this will take some thought. You will have a chance to revise your hypothesis as we go through the semester. Be sure to explain how organisms are related (if any are). Tell how they have changed over time if they have, etc. You may feel lost right now or not sure what the heck the instructor is looking for. It is really not that difficult. Simply come up with a hypothesis on the history of life. Remember, we are not asking about the origin of life, just the history of it once it started. Tell from the point life began how did it change, etc. till now. Who is related to whom if there are any relations?

This one will be your Journal Entry 1 in Forum. The Journal is a special area in Forum that is only visible to you and to your instructor. You will be tracking the progress of your ideas through the course in the various journal posts that will be assigned. You can type your hypothesis in the box on the journal page or better yet, write your answer in Word, then cut and paste it into the journal entry area.

Post your Journal Entry 1 in Moodle:

This is a critically important assignment.

We will test this hypothesis throughout the rest of the semester.