class: center, top, title-slide .title[ # <strong>Demographic Stochasticity - in-class Experiment</strong> ] .subtitle[ ## <a href="https://eligurarie.github.io/EFB370/">EFB 370: Population Ecology</a> ] .author[ ### <strong>Dr. Elie Gurarie</strong> ] .date[ ### <strong>February 16, 2026</strong> ] --- class:inverse ## Demographic Stochasticity .pull-left-60[ .large[ - ***Stochasticity*** means: **Randomness** in **time**. - ***Demography*** is the **Science of Population Dynamics**. Specifically: **births** and **deaths** (and **movements** ... but we're still looking at closed population). Individually, *all* demographic processes are stochastic. - An individual has some *probability* of dying at any moment. - An individual has some *probability* of reproducing at a given time. ] ] .pull-right-40[  ] --- class: inverse .pull-left-60.large[ ## Human Experiment: Process A, N₀ = 5 - Groups of .yellow[**7**;] N₀ = .red[**5 standing**] - Flip a survival coin. - If **TAILS** - you're dead (sit down), - if **HEADS** - you live! (stay standing) - Flip **one** reproduction coin. - If **HEADS** - call on another student to stand! (congrats on your new baby! 🎈🎉) - Record until **extinction** or 20 generations - 8 minutes (as many replicates as you can) ***Enter data at QR code or here:*** https://tinyurl.com/527v7afd ] .pull-right-40[ .center[<img src='images/qr_datasheet.png' width='60%'/>] ] --- class: inverse .pull-left-60.large[ ## Human Experiment: Process A, N₀ = 10 - Groups of .yellow[**14**]; N₀ = .red[**10 standing**] - Flip a survival coin. - If **TAILS** - you're dead (sit down), - if **HEADS** - you live! (stay standing) - Flip **one** reproduction coin. - If **HEADS** - call on another student to stand! (congrats on your new baby! 🎈🎉) - Record until **extinction** or 20 generations - 8 minutes (as many replicates as you can) ***Enter data at QR code or here:*** https://tinyurl.com/527v7afd ] .pull-right-40[ .center[<img src='images/qr_datasheet.png' width='60%'/>] ] --- class: inverse .pull-left-60.large[ ## Human Experiment: Process B, N₀ = 3 - Groups of .yellow[**7**]; N₀ = .red[**3 standing**] - Flip a survival coin. - If **TAILS** - you're dead (sit down), - if **HEADS** - you live! (stay standing) - Flip .red[**two**] reproduction coins. - If **1 HEAD** - one baby! (🎈🎉) - If **2 HEADS** - two babies! (🎈🎉🎈🎉) - Record until **extinction** or 20 generations - 8 minutes (as many replicates as you can) ***Enter data at QR code or here:*** https://tinyurl.com/527v7afd ] .pull-right-40[ .center[<img src='images/qr_datasheet.png' width='60%'/>] ] --- class: inverse .pull-left-60.large[ ## Human Experiment: Process B, N₀ = 6 - Groups of .yellow[**14**]; N₀ = .red[**6 students standing**] - Flip a survival coin. - If **TAILS** - you're dead (sit down), - if **HEADS** - you live! (stay standing) - Flip .red[**two**] reproduction coins. - If **1 HEAD** - one baby! (🎈🎉) - If **2 HEADS** - two babies! (🎈🎉🎈🎉) - Record until **extinction** or 20 generations - 8 minutes (as many replicates as you can) ***Enter data at QR code or here:*** https://tinyurl.com/527v7afd ] .pull-right-40[ .center[<img src='images/qr_datasheet.png' width='60%'/>] ]