Flashcard Set Preview
Side ASide B
most primitive in a particular lineage.
- Darwin’s visit to the Galapagos Islands was the ‘laboratory...
- Darwin’s view was that natural selection acts on the
variations found in populations.
- Adaptations are
any traits that make individuals more successful in a particular environment.
- Unique traits, like the hemoglobin of llamas and camels ...
unique adaptation to harsh, but different environments.
Populations evolve; individuals...
- Mutation produces alleles as
new genetic variation.
- Variation can be introduced into populations by
migrants, crossing over, and sexual reproduction.
- Neutral mutations ____ ____ ____ ____ an organism.
neither harm nor help
- Directional selection causes one extreme phenotype
to have greater success.
- Stabilizing selection causes extreme phenotypes
to be at a disadvantage.
- Stabilizing selection produces what in the reproduction of humans...
an optimum, average birthweight in humans of about 7 pounds and a modal clutch size in some bird species of 6 eggs.
- In a stable, unchanging environment, selection may be
absent or undetectable.
- Disruptive or diversifying selection favors
- When males compete for mating opportunities, sexual selection...
males that are twice as large as females.
- The HbS allele is more frequent in African populations ...
heterozygotes (HbA/HbS) have a reproductive advantage in an environment including malaria.
- The ‘founder effect’ is produced by
introducing a small group onto an island.
- The ‘bottleneck effect’ occurs when
an epidemic drastically reduces the breeding population.
- ‘Genetic drift’ of allele frequencies is more...
population numbers shrink.
- _____ are random, heritable, and potentially useful, but...
- Natural selection does not always favor the big and strong;...
adaptations must match the environmental requirements.
- Artificial selection is a strictly _____ endeavor.
- The fossil record is incomplete for many reasons;
fossilization was/is a rare event.
- Fossils could include
tracks, burrows, teeth, skeletons, or casts.
- Radioisotope dating of fossils uses
the ratio of isotope to daughter product in volcanic rocks.
- Major changes and trends within and between lineages are ...
- Life on earth probably originated prior to ___ BYA during the...
3.5 BYA during the Archean eon.
- Convergence to a similar body shape by sharks and penguins ...
- Wings of bird and butterfly are analogous, not homologous, ...
convergence of form.
- Earlier life forms, such as fossil reptiles, would have ...
- Genes for embryonic development are ‘conservative’ (change ...
they act early.
- Phylogenetic relatedness would not be indicated by mere
similarities of ecology.
- Neutral mutations occur at a constant rate and their accumulation...
- Natural selection may never act on mutations which
The different ‘kinds’ of organisms are also known as different
- The common quality of all separate species is their ______ ______...
- Members of the same species can, at least potentially, ...
- The result of the process of speciation is
complete reproductive isolation.
- Migration or ‘gene flow’ would not promote
species which use external fertilization are less likely to develop
- Stable gene frequencies (genetic equilibrium) is not an
- Genetic divergence by drift or barriers and accumulated ...
- Isolating mechanisms happening before fertilization are
- If the hybrid is inviable, the mechanism is a
‘postzygotic’ or acting after the zygote has formed.
- The usual mode of ‘allopatric speciation’ requires
physical separation or geographic isolation.
- Plants may undergo ‘sympatric speciation’ by forming
‘polyploids’ in a population.
- Divergence from common ancestors (phylogeny) is usually ...
- Phylogeny also refers specifically to the _____ _____ among...
- Evolutionary innovations are acquired during rapid divergences ...