Death: the odds of a specific organism dying come from two factors: the overall odds of death and the size of the organism combined with the way death odds scale with size. This second term can be thought of as size-based toughness. Death frequency establishes the baseline rate at which an organism faces death. When this occurs a size 1 organism always dies. Larger organisms may use their size-based toughness to survive. This scales directly with size. If a size 100 individual is 4 times tougher than a size 1 individual a size 50 individual is 2 times tougher than a size 1. Actual odds of death (combining these terms) are written below the input fields.

Competition: when the population goes over 50 competition begins and becomes more severe as the board fills. Competition has two effects: first, it limits food. At normal competition (100%) this will lower food by 80% with the board full. Competition also causes fights which either wound an organism (increase its chance of death until it heals) or kill it outright. The odds of losing a fight and the damage taken in doing so are both based on the size difference between the combatants. The strength of competition alters both these effects. For instance, at 200% all competition effects are doubled.

Disasters: disasters have a frequency and a strength. The frequency is the odds of a disaster happening, not a counter until one happens, unless you check Disasters are cyclical which causes disasters to happen every [frequency] turns. When a disaster occurs it kills a percent of the population between the two "Disaster kills" values.
Generally, disasters kill organisms following the toughness rules set in the lines above them. E.g., if size 100 organisms are 20 times less likely to die normally than size 1 organisms they will also be 20 times less likely to die in a disaster. This can be overidden by checking "Disasters kill all sizes equally". In this case all sizes of organism are equally likely to die.
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This section includes a pause button, a turn counter, and a notice that appears after 100 individuals have reproduced. This notice will mark what turn this occurred on, which can be used to determine what life histories increase the population faster. The turn counter will also stop if three individuals managed to reproduce but after this the population goes to zero.

The edit mode selectors allow you to switch beween editing the environmental parameters and the species parameters and seeing graphs.

The left side of the screen has 100 spaces that can be occupied by organisms. Organisms will be represented by black silhouettes whose relative size indicates the size of the organism.

The background will be a shade between red and purple. Redder colors indicate that the organism has stored less energy for reproducing, bluer/purple colors indicate that more energy is stored for this purpose.
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There are three options here:

Enter New Values and Restart confirms any changes you have made above and restarts the simulation.

Force Boring Default Values and Restart eliminates competition and disasters and sets the survival advantage of large organisms to 100. This allows you to play around with the basics of the simulator without some of the advanced features in play.

Restart restarts the simulation with the current values.
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Most of these labels are self-explanatory. It is useful to know that all individuals will die of old age between age 900 and 1,100.

Died without reproducing is the number of individuals that have died prior to reproducing at all.

DWR percent is Died Without Reproducing percent, effectively the juvenile mortality percent.

Organisms that have reproduced counts the number of individuals living and dead that have had offspring.
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Energy per offspring: energy required to make an offspring (max 999). The more energy you put in an offspring the larger it will be, topping out at 50% adult size.

Chart: the chart shows energy usage. At every size an organism allocates energy to growth and/or reproduction. Together these add up to 100% of all energy. The more red at a given size the more energy the organism spend on reproduction and the less on growth.
However, organisms can only store energy equivalent to their body size times 10. A blue line marks at what size an organism could hold enough energy to reproduce. Organisms can begin storing energy before this, but that can be a waste of energy.

Straight lines: this makes the lines on this chart straight, drawn from start to midpoint to end (which is always size 100, 100% of energy used to reproduce). If unchecked the lines are curved (technically quadratic bezier curves) which "rounds" the corners of the chart.

Line between start and finish, no midpoint: this eliminates the midpoint on the chart. Now the line simply runs start to end.

Size at sexual maturity: defines how large an organism is before it begins storing any energy for reproduction. Using this input field directly is the easiest way to prevent an organism from spending any energy on reproduction until a certain size.

Midpoint: Without a midpoint organisms simply spend no energy until sexual maturity and then progress evenly to 100% of energy on reproduction at size 100. A midpoint allows you to make more interesting energy allocations, as the energy graph will connect start, midpoint, end point rather than simply start to end. You can also set a midpoint by clicking on the chart, which will update the numbers in these fields.
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