Today is rung 3 of 4 on this topic
Heredity, genes and natural selection
Can do: Explains how traits are inherited and how selection changes a population over generations.
Why it matters
Natural selection is the most misunderstood idea in biology โ the individual-versus-population distinction is where it goes wrong.
What it looks like when it's wobbly
Thinks individuals adapt during their lifetime and pass on the change โ the giraffe-stretched-its-neck version.
โฑ๏ธ Two-minute check
"Did giraffes get long necks by stretching? Explain what actually happened."
Solid looks like: Variation existed, longer-necked ones survived and reproduced more, the population shifted.
The full activity for this topic ยท 30 minutes
Beak Selection Game
- 1Each player gets a different "beak" and thirty seconds to collect food.
- 2Count what each beak collected from each food type.
- 3Remove the least successful beak from the next round โ that's selection.
- 4Change the available food and watch which beak now wins.
- 5Discuss what happens over a hundred generations, and that no individual beak ever changed.
If it's too hard
Two beak types, one food type.
If it's too easy
Model a Punnett square for a real trait and predict offspring ratios.
Say this
"No giraffe's neck ever grew. So how did the average neck in the population get longer?"