Plotting Graphs

Most graphs included in Biology reports and scientific papers, are scatter plots, line plots, box plots, and bar graphs as shown below,

An easy way to draw these graphs is to use the free software jamovi available here. We used jamovi to make each of the graphs shown above, and these are perfectly good for reports and assignments. You could use more sophisticated (complicated) software like R or plot.ly (online here) to draw graphs if you wish but jamovi—which uses R in the background—does a nice job and is easy to use. See below for the steps to producing a graph in jamovi.

DATA

Before you begin click on the big + in the upper right corner and go to the jamovi library and load the scatter module. Now get or create a dataset:

  1. if you already have your data in Excel or some other spreadsheet, save the file as a csv file and import it into jamovi. Your spreadsheet should have the variables in columns, with the variable name at the top of the column and one row per observation
  2. if you don't yet have your data in a spreadsheet you can use jamovi to enter your data. Select the bars in the upper left corner and choose New
  3. Enter your data on the spreadsheet with one row per observation and one column per variable
  4. To change the column names and the kind of variable in the column, double click on the column name. Use column names that will make sense on the final graph, with units as shown below
  5. When you are finished, click on those bars again and either Save As (to save in jamovi’s file format) or Export (to save as a csv file).

GRAPHS

Now make a graph as follows:

  1. Open your dataset in jamovi by clicking on the bars in to upper left corner and then Open. You will have to navigate to the location of your file but jamovi keeps track of it’s location and puts it in the Recent list.

  2. Under Analyses select Exploration > Descriptives

  3. Under Plots, choose the kind of plot you want, put the variables you want to plot into the Variables box and any categorical variable that you want to plot as separate graphs into the Split By box. jamovi will automatically generate the requested graphs in the pane on the right

  4. To change the default appearance of the graphs click on the 3 dots in the upper right corner, and choose the plot theme and other details.

  5. To copy a graph to your word processor, right (control) click on the graph and choose Image>Copy, then paste it into your word processor. Choose Image>Save to save it as a pdf that you can later import into your word processor as needed

  6. To make a scatter diagram choose Exploration>scatterplot and proceed as above.

 Things to remember when drawing graphs:

  • you must clearly label the x and y-axes, giving units as needed
  • use histograms only to show the distribution of continuous variables
  • if you use different symbols or line styles on a graph, these must be identified in a legend on the graph
  • usually you do not need more than 5 or so numbers labelled on each axis
  • tic marks are best on the outside of axes, and usually not more than 5-10 are needed
  • avoid clutter
  • it is a nice touch to add a picture of your study organism as shown in the Dynamite and scatter plot above
  • it is OK to use colour and this often makes a graph easier to read; check with your instructor, though, especially if a paper copy is required

I've spent more time than many will believe [making microscopic observations], but I've done them with joy, and I've taken no notice those who have said why take so much trouble and what good is it?

Antonie van Leeuwenhoek

It's a parts list... If I gave you the parts list for the Boeing 777 and it had 100,000 parts, I don't think you could screw it together and you certainly wouldn't understand why it flew

Eric Lander

What is true for E. coli is also true for the elephant

Jacques Monod

The world becomes full of organisms that have what it takes to become ancestors. That, in a sentence, is Darwinism

Richard Dawkins

Shall we conjecture that one and the same kind of living filaments is and has been the cause of all organic life?

Erasmus Darwin

Nature proceeds little by little from things lifeless to animal life in such a way that it's impossible to determine the line of demarcation

Aristotle

Cells let us walk, talk, think, make love, and realize the bath water is cold

Lorraine Lee Cudmore

In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation. Light will be thrown on the origin of man and his history

Charles Darwin

It is my belief that the basic knowledge that we're providing to the world will have a profound impact on the human condition and the treatments for disease and our view of our place on the biological continuum

J. Craig Venter

Imagine a house coming together spontaneously from all the information contained in the bricks: that is how animal bodies are made

Neil Shubin

A grain in the balance will determine which individual shall live and which shall die - which variety or species shall increase in number, and which shall decrease, or finally become extinct

Charles Darwin

The stuff of life turned out to be not a quivering, glowing, wondrous gel but a contraption of tiny jigs, springs, hinges, rods, sheets, magnets, zippers, and trapdoors, assembled by a data tape whose information is copied, downloaded and scanned

Steven Pinker

We wish to discuss a structure for the salt of deoxyribose nucleic acid. (D.N.A.). This structure has novel features which are of considerable biologic interest

Rosalind Franklin

We are biology. We are reminded of this at the beginning and the end, at birth and at death. In between we do what we can to forget

Mary Roach

The systems approach to biology will be the dominant theme in medicine

Leroy Hood

I've always been interested in animal behavior, and I keep reading about it because it's so surprising all the time - so many things are happening around us that we neglect to look at. Part of the passion I have for biology is based on this wonderment"

Isabella Rossellini

Because all of biology is connected, one can often make a breakthrough with an organism that exaggerates a particular phenomenon, and later explore the generality

Thomas Cech

Nothing in Biology makes sense except in the light of evolution

Theodosius Dobzhansky

Biology is now bigger than physics, as measured by the size of budgets, by the size of the workforce, or by the output of major discoveries; and biology is likely to remain the biggest part of science through the twenty-first century

- Freeman Dyson

Nothing can be more incorrect than the assumption one sometimes meets with, that physics has one method, chemistry another, and biology a third

- Thomas Huxley