WITH ANSWER RATIONALES 2026
◉ Population.
Answer: All the organisms of a particular species living in the same
place at the same time
◉ Gene Pool.
Answer: All the alleles of all the genes in a species or population
◉ Natural Selection.
Answer: Differential reproduction based on heritable traits
◉ Biological fitness.
Answer: The ability of an individual to produce surviving, fertile
offspring relative to that ability in other individuals in the
population
◉ Facts of Natural selection.
Answer: - requires varied population
-does not create new traits or alleles
-mutations do not occur to solve problems
,-adaptations do not occur because organisms want or need them
-evolution is not progressive
-nat. sel. does not change an organism over its lifetime
-does not make perfect organisms
-A fitness trade-off is a compromise between traits in terms of how
those traits perform in the environment
◉ Fossil Record.
Answer: -imprints or remains of organisms that lived in the past
-reveals the appearance (and disappearance) of organisms in a
historical sequence
◉ Biogeography.
Answer: -the study of the geographic distribution of species that
first suggested to Darwin that today's organisms evolved from
ancestral
-species in the same area tend to be more closely related to one
another
-must also consider Continental Drift
◉ Homologous structures.
Answer: -comparative anatomy reveals this
-similarity due to shared ancestry
,-different functions, different shape on outside, BUT similar bones
inside
◉ Vestigial traits.
Answer: similar in structure but no longer functional
◉ Comparative Embryology.
Answer: early stages of development are very similar
-developmental homology
-embryos of vertebrates begin similarly but then develop differently
◉ Molecular biology.
Answer: studies look to DNA, RNA, and proteins for differences and
similarities between organisms to determine how long they may
have shared a common ancestor
◉ Anatomy.
Answer: the study of an organism's physical structure
◉ Physiology.
Answer: the study of how the physical structures in an organism
function
, ◉ Five causes of Evolution.
Answer: 1. Genetic Drift
a. Bottleneck
b. Founder Effect
2. Gene Flow
3. Mutation
4. Natural Selection
5. Nonrandom mating (including
sexual selection)
◉ Genetic Drift.
Answer: - any change in allele frequencies in a population due to
chance
- random with respect to fitness
>especially prevalent in small
populations
◉ Two cases of Genetic Drift.
Answer: - Founder Effect
-Bottleneck Event
◉ Bottleneck Event.