Natural Selection/Adaptation Station
What process allows organisms with helpful traits to survive and reproduce?
Natural selection
What is a mutation?
A change in DNA
What is a fossil?
Preserved remains or evidence of an organism
What is speciation?
Formation of new species
What is genetic drift?
Random change in allele frequencies
Who developed the theory of natural selection?
Charles Darwin
Are all mutations harmful?
No
What does the fossil record show?
Changes in organisms over time
What is reproductive isolation?
When populations can no longer successfully reproduce together
Genetic drift affects which populations most strongly?
Small populations
What does biological fitness mean?
The ability to survive and reproduce
What provides the original source of genetic variation?
Mutations
Why is the fossil record evidence for evolution?
It shows species changing and appearing through time
How can a mountain range lead to speciation?
By separating populations
How does antibiotic resistance evolve?
Resistant bacteria survive and reproduce
Why are polar bears white?
Camouflage in snowy environments
What is variation?
Differences among individuals in a population
What are homologous structures?
Structures with similar anatomy due to common ancestry
What happens when isolated populations evolve differently for long periods?
New species may form
What is directional selection?
Selection favoring one extreme trait
Why are adaptations passed to future generations?
Organisms with beneficial traits reproduce more often
Why are mutations important to evolution?
They create new traits for natural selection to act upon
What are vestigial structures?
Reduced structures with little or no current function
Why is reproductive isolation important for speciation?
It prevents gene flow between populations
What is the difference between stabilizing and disruptive selection?
Stabilizing favors average traits; disruptive favors both extremes