Evolution
change over time
evolution
Evidence of evolution includes... (list all five)
fossils, biogeography, comparative anatomy, developmental (embryology), and molecular biology
What is an adaptation?
An adaptation is a heritable trait or behavior that enhances an organism's ability to survive and reproduce in its specific environment.
Define evolutionary mechanism.
Evolutionary mechanisms are the systems that drive the process of evolution.
Most scientists believe that all forms of life can trace their origins back to a single ______ ______.
common ancestor
_______ confirms the existence of now extinct species.
Fossils
What are the six key components of natural selection?
Inherited variation, Competition, Environmental pressures, Adaptations, Genes, and Evolution
List the five mechanisms of evolution.
The five mechanisms of evolution are: natural selection, gene flow, mutation, non-random mating, and small population/genetic drift.
Evolution occurs slowly or _______.
gradually
__________: slow, consistent evolutionary change, in which species undergo small, steady genetic or morphological changes over time.
Gradualism
Natural selection causes _________ to become _______. Natural selection requires ________ ________.
Natural selection causes populations to become adapted. Natural selection requires inheritable variation.
What is a mutation? How do mutations relate to evolution?
Mutations are changes in genetic material (DNA) that can be neutral, harmful, or helpful to an organism's fitness. Mutations provide the genetic variation required for populations to change over time.
Two different organisms are alike, they share this in their bloodline
a common ancestor
______ ____________: sudden, fast evolutionary change, in which species undergo large genetic or morphological changes over time without previous transitional forms.
Abrupt appearance
What are the types of natural selection and the phenotypes they favor?
Directional selection favors one extreme phenotype over the other. Stabilizing selection favors intermediate phenotypes. Disruptive selection favors both extreme phenotypes.
What kind of changes does genetic drift produce?
small, random changes
Charles Darwin created the theory of evolution by natural selection. On the Galápagos islands, Darwin observed different types of _______, with each island hosting a distinct species. These species exhibit varying ____ ______, which are adaptations to their respective primary ____ sources.
Charles Darwin created the theory of evolution by natural selection. On the Galápagos islands, Darwin observed different types of finches, with each island hosting a distinct species. These species exhibit varying beak sizes, which are adaptations to their respective primary food sources.
__________ _______ are organisms that exhibit traits common to both an ancestral group and its derived descendant group, acting as intermediate links in evolution. These fossils document the gradual, incremental transformation of species over geological time.
Transitional forms
_____________ is when species produce more offspring than can survive to maturity, causing __________ for limited resources. _________ is one of the key components of natural selection and ensures that only the best-adapted individuals survive and pass on their traits.
Overproduction is when species produce more offspring than can survive to maturity, causing competition for limited resources. Competition is one of the key components of natural selection and ensures that only the best-adapted individuals survive and pass on their traits.
A flood that kills most individuals in the population is an example of what kind of mechanism AND type?
small population/genetic drift and bottleneck effect