Natural Selection: Lizard Population
Group: Claudia & Carly

Introduction: Natural selection is the process whereby organisms better adapted to their environment tend to survive and produce more offspring. The theory of its action was first fully explained by Charles Darwin and is now believed to be the main process that brings about evolution. This second hand investigation models natural selection and the survival of the fittest as it shows how species can become extinct due to a missing characteristic, in this case, the characteristic is their colour.
Aim- to model natural selection.
Hypothesis- the red lizards will eventually die out due to its ability to attract the predator. Materials- * set of “territory lizard” card: 15 red, 15 orange and 15 yellow * offspring selector disc (four sided) * prey selector disc (six sided) * blue tack * pins Method 1. Take out 10 cards of each colour from the set, put aside the remaining cards(they’ll be used for the new offspring) 2. Shuffle the 30 cards and deal out 15 pairs in a line. 3. Examine each pair and determine the type of offspring produced, from the table below. Parents | offspring | Red x Red | Red | Yellow x Yellow | Yellow | Red x Yellow | Orange | 4. If there’s any other colour combination, spin the offspring selector disc. Parental cross | Disc stops on | Colour offspring | Red x Orange | 1 or 2 3 or 4 | Red Orange | Yellow x Orange | 1 or 2 3 or 4 | Yellow Orange | Orange x Orange | 1 2 or 3 4 | Red Orange Yellow |

5. Spin the predatory disc, to determine which lizard will be eaten and remove the indicated colour. 6. Repeat step 5 fourteen more times, place the 15 “dead” lizards in spare card pile 7. Repeat steps 2, 3 and 4 until you have a data set of at least 5 years. 8. At the end of each year record the number of lizards remaining in table form.

Results – territory Lizard population. The yellow territory lizard was the survivor of the three coloured territory lizards. Year | Red | Orange | Yellow | Total | 1 | 10 | 10 | 10 | 30 | 2 | 3 | 12 | 15 | 30 | 3 | 0 | 12 | 18 | 30 | 4 | 0 | 12 | 18 |