Deck 6: Speciation and Phylogeny

Question 1

Which of the following statements about plant speciation and hybridization is false?

A) Most plant species trace their origin to polyploid speciation.
B) Bread wheat is the ancestral diploid wheat plant.
C) Modern plant geneticists use chemicals to induce meiotic and mitotic errors to try to create new hybrid plants with special qualities.
D) Bread wheat grown widely today is the result of several hybridization events.

Answer 1

Bread wheat is the ancestral diploid wheat plant.

Question 2

Plant biologists estimate that ________ of living plant species are descendants of ancestors formed by polyploidy speciation.

A) 50%
B) 20%
C) 80%
D) 100%

Answer 2

80%

Question 3

After reading the paragraphs below, answer the question(s) that follow(s).
In 2004, scientists announced the discovery of the fossil remains of some extremely short early humans on the Indonesian island of Flores. The new species has been named Homo floresiensis. One hypothesis is that H. floresiensis evolved from Homo erectus, another early human species. How did a population of H. erectus become isolated on this remote island? Early humans constructed boats and rafts, so perhaps they were blown far off course by strong winds during a storm.
H. erectus averaged almost 6 feet in height, but the remains show that adults of H. floresiensis were only about 3 feet tall. It's hypothesized that limited resources on this hot and humid island (only 31 square miles) exerted selection pressure and succeeding generations began to shrink in size. Small bodies require less food, use less energy, and are easier to cool than larger bodies. Evolution of small size in similar circumstances has been observed in many other species, but never before in humans. This find demonstrates that evolutionary forces operate on humans in the same way as on all other organisms.

-If H. floresiensis could be shown to breed with H. erectus and the offspring were of normal size, one could conclude that

A) the genes for small stature are uniformly recessive.
B) the found H. floresiensis remains were from malnourished individuals whose failure to reach full size was a result of limited food resources in their habitat.
C) H. floresiensis did not suffer from hypothyroidism.
D) H. erectus remains were not from malnourished individuals.

Answer 3

the found H. floresiensis remains were from malnourished individuals whose failure to reach full size was a result of limited food resources in their habitat.

Question 4

The process where chance events can cause allele frequencies to fluctuate unpredictably from one generation to the next is called

A) the bottleneck effect.
B) microevolution.
C) genetic drift.
D) the founder effect.

Question 5

What is not an example of sexual dimorphism?

A) peacock feathers
B) lion mane
C) rhino tail
D) elk antlers

Question 6

Which mollusc has complex camera lens-type eyes?

A) marine snail
B) squid
C) abalone
D) nautilus

Question 7

After reading the paragraphs below, answer the question(s) that follow(s).
The first fossil of Archaeopteryx, which lived about 150 million years ago, was found in the Solnhofen Quarry in Germany. Archaeopteryx has an interesting collection of characteristics that led to the hypothesis that it represented an evolutionary transition between modern-day birds and small bipedal dinosaurs. The fossil reveals the imprint of feathers, which connect Archaeopteryx to birds, although they don't present direct evidence of flight.
Unlike birds, however, the fossil record reveals that Archaeopteryx had teeth, functional claws on the wings that may have been used for climbing trees or holding prey, and a long, bony tail. Birds have a fused collarbone, and this was found in Archaeopteryx also. However, there were differences in the structure of the sternum. In birds, the sternum is keeled (raised and slightly concave). The keel of the sternum serves as an attachment site for the flight muscles. Archaeopteryx had a flat sternum, similar to that found in reptiles.

-The absence of a keeled sternum in Archaeopteryx suggests that this species

A) could not fly.
B) could not fly as well as most modern birds.
C) could not run.
D) could not take off from the ground.

Question 8

Modifying species by selecting and breeding individuals with desired traits over many generations is

A) natural selection.
B) artificial selection.
C) selective nature.
D) species selection.

Question 9

Evolutionary biologists can put together a logical sequence of events on how a group of organisms evolved from a common ancestor by using all of the following methods except

A) fossil records.
B) species behaviour.
C) structural homologies.
D) molecular similarities.

Question 10

After reading the paragraph below, answer the question(s) that follow(s).
Desert pupfish live in springs of the American Southwest. Today there are about 30 species of pupfish, but they all evolved from a common Pleistocene ancestor. The southwestern United States was once much wetter than it is now, and the Pleistocene pupfish flourished over a wide geographic area. Over thousands of years, however, the Sierra Nevada mountain range was pushed upward by geological forces, blocking rainfall from the Pacific Ocean. As the large lakes dried up, small groups of pupfish remained in springs and pools fed by groundwater seepage. Now, although many of these small springs still have pupfish, each population has evolved to become very different from pupfish in other springs.

-Individuals of the different pupfish species presumably would not mate with each other even if they were housed together. Which of the following is unlikely to be a possible reason for this?

A) evolved anatomical changes that render the species incompatible
B) evolved behavioural changes that render the species incompatible
C) evolved genetic incompatibilities between egg and sperm
D) evolved changes in the genetic code