This applet models evolution. In genetics, a sequence of amino acids (protein) is coded for by a sequence of nitrogenous bases (DNA). A group of THREE consecutive bases (codon) codes for ONE amino acid.
This applet works differently. Here, three bases (a codon) determine one letter of the English alphabet. Therefore, the DNA sequence in light gray on the second line determines the blue English sequence on the first line. There are 64 different codons that represent 26 English letters, just as in real biology, the 64 codons represent 20 amino acids.
Each sequence (you can think of it like a virus) reproduces asexually, yielding a fixed number of offspring, selectable by the user from 2 to 30. Each "daughter" virus undergoes a single point mutation at one of the nitrogenous DNA bases.
Each child is "scored" - one point is assigned for each letter in the English message that is identical to the target, and zero otherwise. The child with the highest scsore might be thought the "fittest" in a Darwinian sense. It becomes the new parent.
Notice that a change in a single base often has no effect on the English message (which is properly termed the phenotype), due to the redundency of the code. When one child finally achieves the target phrase (a line from Shakespeare's Macbeth), the applet ends.
The user can increase the number of children in each generation (cycle) by clicking on the "More Offspring" box, and can decrease the number of children by clicking on the "Less Offspring" box. Clicking on the "Pause" button suspends the applet while you pursue another activity.
© 2003-2011 by Lawrence T. Sein. All rights reserved.
Send questions to:lseinjr@hotmail.com