Exam 18: Macroevolution

The slow evolutionary change in organisms over a long period of time is referred to as ________.

"Speciation may occur rapidly and is caused by a few genetic changes in important genes. This statement is best associated with

Use this information for the question below. Many fossils have been found showing that the horse evolved from a small browsing animal to a large grazing plains dweller (the modern horse), but the fossil record does not show all the intermediate forms. -The punctuated equilibrium model says that these gaps are due to:

Large anatomical changes can occur without speciation.

A very large dog and a very small dog might be considered different species based on which of the following isolating mechanisms?

Eldredge and Gould are credited with establishing the concept of:

When is speciation most likely to occur?

Which kind of evidence would be of the least use to taxonomists?

A common means of speciation in plants but not in animals is:

What factor would make sympatric speciation less likely for a species?

The relatively quick appearance of a new species of organism is an example of ________.

Who is credited with developing the binomial system of scientific names?

Refer to the following scenario and then answer the questions that follow. A European species of marsh grass called Sparitina maritima has 2n = 60. A similar species native to North America, S. alterniflora, has 2n = 62. In 1835, the North American species was found growing near the European species near Southampton, England, having been accidentally imported. Occasional sterile hybrids were noted. In 1895, a new species, S. anglica, was first identified at Southampton and subsequently became very common. The new species has been identified as a fertile hybrid of the original two species. -What is the 2n chromosome number of the sterile hybrids that form between the original two species, S. maritima and S. alterniflora?

Two species of squirrels live on either side of the Grand Canyon. They are an example of:

-The biological species concept cannot be used for:

The gradualism model of evolution says that gaps in the fossil record are due to:

A horse has 2n = 64 and a donkey has 2n = 62. The hybrid of these two species, the mule, has 63 chromosomes and is sterile. Why are mules sterile?

Fruit fly species all look more or less alike. If you have a male and female fruit fly, what would be the best way to determine that they are the same species?

"Speciation may occur because of accumulation of many minor genetic changes in a population. This statement is best associated with:

A small population of insects lives in a forest, but they are highly specialized to lay their eggs only on the ripening fruit of one species of fig tree. What are the chances that this species will expand and multiply, or become extinct?