Evolution Basics
The process by which species change over long periods of time.
What is evolution?
Evolution happening very slowly and steadily over time.
What is gradualism?
Two identical alleles, like AA or aa.
What is homozygous?
The process where cells become specialized for a specific function.
What is differentiation?
Remains or traces of organisms from long ago.
What are fossils?
Darwin studied these birds on the Galápagos to understand natural selection.
What are finches?
Evolution happening in quick bursts followed by long periods of no change.
What is punctuated equilibrium?
The physical characteristics an organism shows.
What is phenotype?
Chemical messages that help cells decide which genes to activate.
What is cell signaling?
This record shows gradual changes in species over millions of years.
What is the fossil record?
The natural differences among individuals in a species that allow some to survive better.
What is variation?
When unrelated species develop similar traits because they live in similar environments.
What is convergent evolution?
Mendel discovered dominant and recessive traits by studying these plants.
What are pea plants?
In this stage of life, cells receive instructions that determine their roles.
What is embryonic development?
Layers of sedimentary rock that help determine fossil age.
What are geological strata?
This scientist proposed natural selection as the mechanism for evolution.
Who is Charles Darwin?
When two species evolve together because they depend on each other.
What is coevolution?
A cross between Dd × Dd gives this probability of a recessive phenotype.
What is 25%?
These are turned “on” or “off” to create different types of cells.
What are genes?
Fossils that fill gaps between major organism groups, like dinosaur → bird.
What are transitional fossils?
When a species splits into two due to environmental pressure and adaptation.
What is speciation?
Structures that show common ancestry, like a human arm and a bat wing.
What are homologous structures?
When genes separate independently and don’t influence each other’s inheritance.
What is the principle of independent assortment?
The idea that all cells have the same DNA but look different because only certain genes activate.
What is selective gene expression?
The study of where organisms live and how their distribution supports evolution.
What is biogeography?