4-step Framework
Identify the variation in this scenario:
Cane toads were introduced to Australia in the 1930s, and are considered an invasive species. As they spread across the continent, scientists noticed something surprising: the toads at the edge of the invasion front tend to have longer legs than those in older populations. These long-legged toads can move farther and faster, allowing them to reach new areas first. Over time, the population of toads at the front has become dominated by individuals with longer legs.
What is different lengths of legs?
The type of selection that Darwin described in his original theory.
What is Natural Selection?
The human appendix, whale pelvic bone, and snake leg bones are examples of this type of structure.
What are vestigial structures?
Your best current understanding of something in the world.
What is a Model?
A graph about plant growth has a y-axis labeled “height (cm)” and an x-axis labeled “days.” The x-axis represents this variable.
What is the independent variable?
Identify the selective pressure in this scenario:
Cane toads were introduced to Australia in the 1930s, and are considered an invasive species. As they spread across the continent, scientists noticed something surprising: the toads at the edge of the invasion front tend to have longer legs than those in older populations. These long-legged toads can move farther and faster, allowing them to reach new areas first. Over time, the population of toads at the front has become dominated by individuals with longer legs.
What is the accessibility of resources at the invasion front?
When humans intervene and use selective breeding with other organisms.
What is artificial Selection?
The wings of butterflies and the wings of bats both allow flight but evolved independently. These are examples of this type of structure.
What are analogous structures?
An if-then statement that predicts the outcome of a scientific experiment.
What is a hypothesis?
A graph about plant growth has a y-axis labeled “height (cm)” and an x-axis labeled “days.”This is the dependent variable.
What is the height in cm?
The term used to describe an individual's ability to survive and reproduce.
What is Fitness?
Male peacocks grow large, colorful tails even though they make them more visible to predators. This is an example of this type of natural selection.
What is sexual selection?
Early embryos of chickens and humans both show tails, even though only one develops a tail in adulthood. This similarity supports this idea.
What is common ancestry?
The part of an experiment that ensures it is your independent variable affecting your dependent variable.
What is a control group?
This is where the title of your graph should go.
What is at the bottom?
Identify the adaptation that allowed for Differential Reproductive success in this scenario:
Mosquitoes that spread diseases like malaria and dengue are often controlled with chemical sprays. At first, spraying greatly reduced mosquito populations. But within just a few years, more and more mosquitoes survived treatments that used to kill them. Today, in many areas, populations of mosquitoes are dominated by individuals that can withstand those same chemicals.
What is resistance to the chemical sprays?
In an environment with both light-colored sand and dark-colored rocks, mice with very light or very dark fur survive better than medium-colored mice. This pattern of selection is called this.
What is disruptive selection?
These slit-like structures are found in early embryos of fish, turtles, rabbits, and humans, but later develop into different adult features.
What are pharyngeal slits?
Three pieces of lab safety equipment
What is a hair tie, lab goggles, fire blanket, gloves, closed-toed shoes, or biohazard waste bin?
This is a term used to describe the axes on a graph. When creating your graph you need to make sure that this includes the range of your data, and increases or decreases in a consistent manner.
What is the scale?
What is the fourth step of the four-step framework?
What is evolution: a description of how the POPULATION changes over time?
Human babies that are born very small or very large are less likely to survive than babies of average size. This is an example of this type of selection.
What is stabilizing selection?
When Scientists use this kind of evidence to study evolutionary relationships: Humans and chimpanzees share about 98–99% of their DNA, while humans and mice share about 85%.
The type of variable that could affect the dependent variable if not held constant.
What is a confounding variable?
Fire can grow, spread, and use energy, but it is not considered this because it does not have cells.
What is alive/living?