Darwins Observations
What did Darwin notice about heritable traits in finches from different islands?
He noticed variation in traits like beak shape depending on the finch’s island habitat.
What is temporal isolation and how does it affect reproduction?
Temporal isolation occurs when species reproduce at different times.
What was the composition of Earth’s primitive atmosphere compared to today’s?
It was hot, volcanic, and composed mainly of gases like methane, ammonia, and water vapor.
Who conducted the first experiment simulating early Earth conditions to test abiogenesis?
Stanley Miller and Harold Urey.
List the correct order of the taxonomic hierarchy from most general to most specific.
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
How does 'survival of the fittest' relate to reproductive success?
It means individuals with traits best suited to their environment are more likely to reproduce.
How does mechanical isolation maintain reproductive boundaries between closely related species?
Mechanical isolation happens when reproductive structures are incompatible.
Name two major gases that were most abundant on early Earth and explain their origin.
Methane and ammonia were abundant due to volcanic outgassing and early chemical processes.
What types of organic molecules were produced in Miller and Urey’s experiment?
Amino acids and other organic molecules.
What is the highest rank in the taxonomic hierarchy and what does it include?
Domain; it includes Archaea, Bacteria, and Eukarya.
How does natural selection differ from artificial selection in terms of selective pressure?
Natural selection is driven by environmental pressures, while artificial selection is human-directed.
Why does gametic isolation often prevent fertilization even when mating occurs?
Gametic isolation prevents fertilization due to incompatible gametes.
Which gas essential for modern respiration was missing from early Earth’s atmosphere and why?
Oxygen was least abundant because photosynthetic organisms had not yet evolved.
What assumption about early Earth did the spark discharge experiment rely on to support abiogenesis?
That early Earth's conditions could naturally form life's building blocks.
Which taxonomic rank is the most specific, and how is it used to identify organisms?
Species; it identifies individual organisms uniquely.
Based on fossil records and biogeography, what inference did Darwin make about species divergence over long timescales?
He inferred that species change gradually and adapt to their environment over generations.
How does hybrid inviability reduce gene flow between species?
Hybrid inviability occurs when zygotes fail to develop properly.
How did the lack of oxygen in early Earth’s atmosphere shape the development of anaerobic life forms?
Anaerobic life thrived without oxygen; aerobic life developed only after oxygen levels rose.
How did Miller and Urey’s experiment influence modern hypotheses about the origin of life?
It showed that organic compounds could arise under prebiotic Earth conditions.
How is a genus different from a family, and what does it reveal about evolutionary relationships?
A genus includes closely related species; a family includes several genera
How did Darwin’s theory challenge the static view of species, and what was his broader conclusion about common ancestry?
Darwin concluded all species share a common ancestor and evolve over time via natural selection.
Explain why hybrid sterility is considered a postzygotic barrier and how it contributes to speciation.
Hybrid sterility means the offspring can't reproduce, maintaining species boundaries.
What were the physical and chemical conditions on early Earth that made the formation of organic molecules possible?
High volcanic activity, lightning, UV radiation, and water vapor enabled organic molecule formation.
What are some limitations or criticisms of the spark discharge experiment in explaining life’s origins?
It didn't replicate deep-sea vent conditions or account for all environmental variables.
Define binomial nomenclature and explain why it's important in global scientific communication.
Binomial nomenclature uses genus and species to uniquely name organisms