BIOL 2130 Exam 1

The paradigm shift that resulted from the proposed ideas of Darwin and Wallace changed from _____ thinking to ______ thinking.

typological, population

Reinforcement is most likely to occur when

prezygotic isolating mechanisms are in place

Most causes of speciation are relatively slow, in that they may take many generations to see changes, with the exception of _____.

polyploidy

Vestigial traits and neutral changes in DNA sequences are good examples of ___

Nonadaptive traits

The recessive allele that causes sickle cell anemia is harmful to homozygous individuals. What maintains the presence of this allele in a population's gene pool?

Heterozygote advantage

Bacterial resistance to human use of antibacterial compounds is an example of...

Directional selection

Different appearances in males and females of a population, such as peacocks and most spider species, are referred to as .....

sexual dimorphism

What is the main difference between autopolyploid and allopolyploid?

the source of the extra chromosomes

Which of the following events would best be described as a case of sympatric speciation?

A new, isolated population of fruit flies is founded by a small group of colonists, who then diverge from the ancestral source population.

Some beetles and flies have antler-like structures on their heads, much like male deer do. The existence of antlers in beetle, fly, and deer species with strong male-male competition is an example of

convergent evolution

Which of the following was not evidence used for Darwin's theory of evolution?

radiometric dating methods

Which of the following is NOT a way in which mutations occur?

sexual reproduction

The largest extinction, measured as a percentage of species that disappeared, occurred at the end of which geological period?

Permian

Which of the following was a cause that led to the Cambrian Explosion?

Predation

Which of the following forms a monophyletic group?

E, F, and G

Which of the following showed their greatest diversity during the Mesozoic era but were a small, less diverse group during the Paleozoic era?

Gymnosperms

Over time, the lineage that led to modern whales shows a change from four-limbed land animals to aquatic animals with two limbs that function as flippers. This change is best explained by

Natural Selection

Which of the following statements regarding the asymmetry of sex is correct?

Female fitness is limited by the ability to gain resources.

The largest unit within which gene flow can readily occur is

A spp

Bearded dragon breeders maintain the purity of breeds by keeping lizards of different breeds apart when they're fertile. This kind of isolationism is most similar to which of the following reproductive isolating mechanisms?

Habitat isolationism

Which of the following organisms likely has the most Hox genes?

Dolphin

Many crustaceans (shrimp, lobsters, crawdads) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of...

A vestigal trait

Giraffe babies of average size are most likely to survive ~6 ft drop following birth.

Stabilizing Selection

A population of nuthatches experienced a significant drought, during which their main source of food was scarce. Larger sized nuthatches were able to withstand the resulting famine,thus increasing average body size among the population.

Directional Selection

Fiddler crabs with extreme claw sizes (small or large) are most likely to survive.

Disruptive Selection

Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact?

Bhehavioral reproductive isolation

Which of the following most strongly supports the common origin of all life on Earth? All organisms ____.

use essentially the same genetic code

Which of the following organisms would be most likely to form a fossil?

common chipmunk

Ichthyosaurs, now extinct, were aquatic reptiles with dorsal fins and tails, similar to those of fish. Their most recent ancestors were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are ____.

adaptations to a common environment and examples of convergent evolution.

When do scientists apply the concept of maximum parsimony?

to decipher accurate phylogenies

An earthquake decimates a ground-squirrel population, killing 98% of the squirrels. The surviving population happens to have broader stripes (on average) than the initial population. If broadness of stripes is genetically determined, what effect has the ground-squirrel population experienced ring the earthquake?

directional selection

Rank the following in order from most general to most specific:

1. Gametic isolation

2. Reproductive isolating mechanism

3. Sperm-egg incompatibility in sea urchins

4. Prezygotic isolating mechanism

2, 4, 1, 3

Which of the following does NOT promote speciation?

gene flow

How are two different species most likely to evolve from one ancestral species?

allopatrically, after the ancestral species has split into two populations

When male elephant seals reach sexual maturity, they leave their group in search of a new population. This can alter the allele frequencies of the population through which of the following mechanisms?

gene flow

Organisms evolve towards a specific end goal, producing the best versions of each species.

False

Geological evidence of the massive asteroid that likely led to the Cretaceous Extinction (and the diversification of mammals) is referred to as the K-Pg Boundary.

True

The collection of all the alleles in a population at a particular time is the gene pool.

F

Evolution can happen whenever any of the conditions of the Hardy-Weinberg equation are not met.

True

Dragonflies are more evolved than fruit flies.

False