Evidence of Evolution
This type of evidence compares anatomical structures between organisms to show shared ancestry; homologous structures indicate common descent.
Homologous structures.
Natural selection acts on these that are heritable and vary among individuals in a population.
Phenotypic traits or heritable variation / heritable traits / genetic variation.
The group of organelles widely accepted to have originated by endosymbiosis and still contain their own DNA (name one).
Mitochondria or chloroplasts (accept either).
Fossils found in progressively older rock layers show change over time. Name the principle that states older layers are below younger layers.
Law/Principle of Superposition.
This term describes random changes in allele frequencies from generation to generation, often important in small populations
.Genetic drift.
The early Earth's atmosphere lacked significant free oxygen. The evolution of these organisms added oxygen to the atmosphere through photosynthesis.
Cyanobacteria (or photosynthetic prokaryotes).
This molecular evidence compares DNA or amino acid sequences across species to infer evolutionary relationships. Give the general term.
Molecular (or genetic) sequence comparison / molecular evidence (DNA/amino acid sequences).
When a small group of individuals establishes a new population with different allele frequencies than the original population, this effect is called the ___ effect (two words).
Founder effect.
Name the hypothesis that describes how mitochondria and chloroplasts originated as free-living prokaryotes taken into early eukaryotic cells.
Endosymbiotic theory (endosymbiosis).
When two unrelated species evolve similar traits because they live in similar environments, this is called what?
Convergent evolution.
This process introduces new genetic variation by creating new alleles and altering sequences; it's the ultimate source of genetic variation.
Mutation.
This term describes a community of microorganisms that lived inside a mineral matrix and are among the oldest known fossils (two words).
Microbial mats / stromatolites.
A pattern in the fossil record where simple organisms appear early and more complex later is consistent with this long-term process; name the pattern or concept (two words).
Increasing complexity over geologic time (or “macroevolutionary trend”
Give two of the three conditions required for natural selection to lead to adaptation (from the standard list: variation, heritability, and one other).
Variation, heritability, differential survival/reproduction (competition/selection) — any two of these.
Outline (in one or two sentences) a plausible sequence of steps—starting from simple organic molecules—that leads toward the first protocell (include at least three steps).
simple organic molecules form (via abiotic synthesis)
monomers polymerize to form macromolecules (like RNA/proteins)
these molecules become encapsulated by lipid membranes forming protocells,
protocells develop catalytic molecules (ribozymes) and replication—leading toward cellular life