Darwin's Theory of Evolution
The island chain where Darwin studied finches and tortoises.
What are the Galapagos Islands?
The process by which humans breed organisms for desired traits.
What is artificial selection?
A group of organisms that can interbreed and produce fertile offspring (one-word definition).
What is a species?
The preserved remains or impressions of ancient organisms found in rock.
What is a fossil?
Selection that favors one extreme phenotype, shifting the population distribution.
What is directional selection?
The name of Darwin’s famous book published in 1859.
What is On the Origins of Species?
Darwin’s first requirement for natural selection: more individuals are born than can survive (short phrase).
What is the struggle for existence? (Or: What is "more individuals are born than can survive"?)
The process that creates new distinct species due to reproductive isolation.
What is speciation?
Structures that are similar because species share a common ancestor.
What are homologous structures?
Selection that favors the intermediate phenotype and selects against extremes.
What is stabilizing selection?
One of Darwin’s three observations: similar species living in different, but ecologically similar, regions (short phrase).
What is "species vary globally"?
Define fitness in evolutionary terms (one sentence).
What is how well an organism can survive and reproduce in its environment?
Reproductive isolation type when two populations breed at different times.
What is temporal isolation?
Body parts that have lost much or all of their original function.
What are vestigial structures?
Selection that favors both extreme phenotypes and can lead to two distinct forms.
What is disruptive selection?
The term for inherited traits that increase an organism’s chance of survival and reproduction.
What is an adaptation?
Name the three things Darwin identified as necessary for natural selection to occur (list).
What are variation, heritable traits (adaptations), and differential survival/reproduction (fitness)?
The type of speciation that occurs when a geographic barrier divides a population.
What is allopatric speciation?
The study that compares early developmental stages across species to show relationships.
What is comparative embryology?
On a polygenic trait bell curve, this selection type would narrow the curve around the mean.
What is stabilizing selection?
The scientist who proposed “acquired characteristics,” a hypothesis Darwin disagreed with.
Who is Lamarck?
Explain why natural selection acts on phenotypes rather than directly on genes (one or two sentences).
What is because natural selection acts on the organism’s traits (phenotypes), and those traits are produced by genotypes, so selection changes allele frequencies indirectly?
Two examples of reproductive isolation barriers.
What are temporal, behavioral, and geographical isolation?
Explain what comparative biochemistry (DNA/amino acid comparisons) can tell us about how closely related two species are (one or two sentences).
What is that more similar DNA or amino acid sequences indicate more recent common ancestry, so species with closer biochemical similarity are more closely related?
Give a short example (one or two sentences) for each of the three types of selection using any organism (label examples directional, stabilizing, disruptive).
What is directional: e.g., peppered moths shifting to dark morphs in polluted areas; stabilizing: human birth weight where average babies survive best; disruptive: a bird population where very small and very large beak sizes are favored for different food sources, splitting the population?