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Welcome to Natural Selection – Peppered Moths.
A highly interactive simulation which investigates natural selection during changes in the environment experienced by peppered moths.
After the title and license screens, we are presented with the help dialog.
Links to other online help and recommended student experiments are displayed together with some useful information.
This help dialog can be accessed at any time from the help menu above.
On first entering the program we are presented with the New Experiment dialog.
Here the initial moth population can be controlled. Initially 15 light coloured and 15 dark melanic peppered moths are displayed.
The relative number of the moths can be changed using either the up and down arrows or simply editing the fields.
An option to have smart moths, which carefully choose where to hide on the tree, is selected by default.
Lighter moths rest on the light lichens while the darker moths seek shade or darker areas.
I recommend you leave this option on unless you are conducting an experiment which requires it to be off.
If off the moths would randomly settle on the branches.
Environmental condition may be selected at this time.
Natural forest – contains trees with extensive lichen growth and represents the forest in the preindustrial period.
Polluted Forest – contains trees with darkened branches and trunks as a result of industrialisation.
Pollution Controlled – shows the effects of pollution laws which saw the lightening of trees over a period of time.
At this stage you can also load saved experiments, which have not been completed or have been set up by teachers
To start the simulation click OK
You are now a moth eating predatory bird.Your objective is to eat 10 moths as fast as possible.
The longer you take the fewer bonus points you will acquire.
To eat a moth, point the tip of the bird’s beak on the moth and click the mouse.
Under normal conditions the darker moths are easier to spot than the lighter ones, however, the lighter ones can still be seen and eaten.
Lighter moths just take more time to spot and you end up with fewer bonus points at the end.
We can see here the moth in the bird’s beak and when the mouse is moved the bird swallows the moth and is ready to eat the next.
Once you have eaten 10 moths you are shown the Next Generation dialog.
This is a good chance to explore the rest of our console before continuing.
Along the bottom we have the New Experiment button with the flask icon. You can start a new experiment at any time by selecting this button.
Next we have the forest environment display and the number of generations so far.
Next we have the forest environment display and the number of generations so far.
Your score is the total of your bonuses in each generation so far.
The forest button brings you back to the main display.
Graphs and data are best observed during the New Generation dialog, as viewing them while you are eating the moths will reduce your score.
Now for the side panels.
You may be viewing this video from the” Learn to Use” page, however, additional videos may also be added to this page in the future.
At the top is the Quick Tips panel which covers many of the items I’ve mentioned.
The My Scores panel, allows you to view your scores and times in each generation.
You may wish to compete with others in the class or your teacher may choose to eliminate those with the lowest scores after each generation.
Returning to the Next Generation dialog, we can see the surviving moths from the last generation, which have bred.
The parents don’t survive until the next generation and the offspring displayed are those which survive through the various stages to become adults.
Unlike the New Experiment dialog, the relative numbers can’t be changed between generations.
You can change the smart moth option and the Environmental conditions if you wish.
We’ll change the environment to Industrial Pollution and click continue.
We can see that the industrial pollution has killed the lichens and considerably darkened the trees.
Lighter moths are easily seen and eaten, while the darker ones are much harder to find.
Normally we would go on for several more generations to investigate what would happen to the moth population under industrial population.
However for the purposes of this demonstration we’ll select the more advanced option of Controlled Pollution.
Under these conditions the lichens start to grow back.
This has little effect initially, but over the following 9 generations the forest slowly returns to its natural state.
I’ll load an experiment which was performed earlier and we can observe typical graphs from this type of experiments.
Here you can see the environmental conditions throughout the generations.
The surviving moth populations after each generation and the trends they reveal.
Starting numbers can also be observed as with deaths in each generation.
Graphs and data can be printed, however, it’s advisable to change the group name found in the options menu before you do so.
Moving on to data – this can also be exported as both CSV and tab delineated text for importing into spreadsheet programs such as Excel.
This product is currently available for Windows XP, Vista , 7 and above.
Macintosh OS X 10.6 and above.
An online version is expected to be released in March 2012.
Visit our web site for more information and to trial this and other programs.