Selection Banner for Evolution Models - Virtual Biology Lab

Evolutionary Trade-offs

While there are many factors that can affect allele proportions in a population, selection is thought to be among the most powerful. Selection effectively shapes the heritable physiology, morphology, and behaviors of populations through differential reproduction among individuals. Natural selection affects traits related to survival and producing offspring, while sexual selection specifically affects traits related to obtaining mates. Often traits that increase an individual’s access to mates, actually decreases their survival. One of the models in this section depicts this evolutionary trade-off.

Models are best viewed on large screens and landscape modes.

Screenshot of Endler's Guppies Model - Virtual Biology Lab

Model 1 – Endler’s Guppies 

This model simulates Endler’s 1980 classic experiment on the balance of sexual selection and natural selection. In guppies, females prefer to mate with males that have lots of spots, but those males are more easily seen by predators. You can manipulate strength of female preference and the number of predators.

Launch Model
Directions – PDF

⇒Links to older versions of each model are found here.

Screenshot of Industrial Melanism Model - Virtual Biology Lab

Model 2 – Industrial Melanism 

This model simulates the classic example of natural selection on color patterns in peppered moths (Biston betularia). When air pollution is low, lichens cover the trees and the light moths are well camouflaged. When air pollution is high, the trees become dark and the light moths stand out. The simulation takes place just prior to the industrial revolution and proceeds through to modern day.

Launch Model
Directions – PDF

⇒Links to older versions of each model are found here.