Vocab
A trait that helps an organism survive.
What is an adaptation?
This type of selection favors one extreme trait.
What is directional selection?
Organisms compete for these because they are limited.
What are resources?
The scientist who developed the theory of natural selection.
Who is Charles Darwin?
Body parts that no longer serve an important purpose.
What are vestigial structures?
This type of selection favors average traits.
What is stabilizing selection?
Random changes in allele frequency in a population.
What is genetic drift?
Charles Darwin traveled to the islands and observed differences with what creatures
What are tortoises and finches?
Similar structures that come from a common ancestor.
What are homologous structures?
This type of selection favors both extreme traits.
What is disruptive selection?
What determines whether a trait is helpful, harmful, or neutral?
What is the environment?
What island did Charles Darwin travel to?
What are Galápagos Islands?
Structures with the same function but different origins.
What are analogous structures?
Birds with larger beaks surviving a drought is an example of this selection.
What is directional selection?
A small group of birds becomes isolated on an island and starts a new population with only a few traits from the original population.
What is the founder effect?
The process where organisms best adapted to their environment are more likely to survive
The process where organisms with helpful traits survive and reproduce more.
What is natural selection?
Average human birth weight is an example of this selection.
What is stabilizing selection?
A natural disaster greatly reduces a population, leaving only a few survivors with limited genetic diversity.
What is the bottleneck effect?
During a drought, finches with larger beaks survived better because they could crack hard seeds. Over time, more finches had this type of beak.
What is larger beaked birds?