Exam 34: The Origin and Evolution of Vertebrates

Use the following information to answer the question. Brown et al. and Morwood et al. reported in 2004 that they had found skeletal remains of a previously unknown type of hominin, now dubbed Homo floresiensis, on the Indonesian island of Flores. These hominins were small (approximately 1 meter tall) with small braincases (approximately 380 cubic centimeters) as compared with other hominins. The remains of H. floresiensis were found alongside handmade stone tools and the remains of dwarf elephants that also inhabited the island, suggesting that H. floresiensis was able both to make tools and to coordinate the hunting of animals much larger than itself. H. floresiensis is estimated to have lived at the site where the remains were found from at least 38,000 years ago to 18,000 years ago. Which would be the most feasible method of figuring out to which other hominin species H. floresiensis was most closely related?

Why do skates and rays have flattened bodies, while sharks are torpedo shaped?

A new species of aquatic chordate is discovered that closely resembles an ancient form. It has the following characteristics: external armor of bony plates, no paired lateral fins, and a suspension-feeding mode of nutrition. In addition to these, it will probably have which of the following characteristics?

Which of the following characteristics occur in Homo naledi?

What is believed to be the most significant result of the evolution of the amniotic egg?

Use the following information to answer the question. Terry catches a ray-finned fish from the ocean and notices that attached to its flank is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker, and two small eyes. Terry concludes it is a hagfish. Terry saved some of the tooth-like objects within the hagfish's round mouth to analyze their composition in his mentor's biochemistry research lab. Terry will find that they are composed of the same protein found in tetrapod ________.

The history of hominin evolution demonstrates ________.

Primate evolution and behavior, such as hunting skills, have been directed in part by the development of depth perception. What anatomical change made depth perception possible?

At one time, Chondrichthyes were thought to have split off from other vertebrates before the evolution of bone. Now we have concluded that the Chondrichthyes split off after the evolution of bone had started. This change demonstrates ________.

Arrange these groups in order from most inclusive (most general) to least inclusive (most specific).

Which of these traits is most strongly associated with the adoption of bipedalism?

Use the following information to answer the question. Due to its system of air sacs connected to the lungs, the respiratory system of birds is arguably the most effective respiratory system of all air-breathers. Upon inhalation, air first flows into posterior air sacs, then into the lungs, and then into anterior air sacs on the way to being exhaled. Thus, there is one-way flow of air through the lungs, along thousands of tubules called parabronchi. If the inner lining of the air sacs is neither thin nor highly vascularized, then what can be inferred about the air sacs?

Fossils of the earliest tetrapods should ________.

Use the following information to answer the question. Brown et al. and Morwood et al. reported in 2004 that they had found skeletal remains of a previously unknown type of hominin, now dubbed Homo floresiensis, on the Indonesian island of Flores. These hominins were small (approximately 1 meter tall) with small braincases (approximately 380 cubic centimeters) as compared with other hominins. The remains of H. floresiensis were found alongside handmade stone tools and the remains of dwarf elephants that also inhabited the island, suggesting that H. floresiensis was able both to make tools and to coordinate the hunting of animals much larger than itself. H. floresiensis is estimated to have lived at the site where the remains were found from at least 38,000 years ago to 18,000 years ago. It is speculated that H. floresiensis and H. sapiens may have lived on Flores concurrently. Suppose researchers obtained mitochondrial DNA samples from the H. floresiensis remains, amplified a 1,000-base-pair sequence via PCR, and compared it to that of several currently living H. sapiens native to Indonesia, North Africa, and North America. Also suppose H. floresiensis were found to differ from the average Indonesian H. sapiens in 28 base pairs, from the average North African H. sapiens in 51 base pairs, and from the average North American H. sapiens in 53 base pairs, while two randomly selected H. sapiens differed from each other in an average of 21 base pairs. What would you surmise from these data?

Which of the following characteristics allowed early gnathostomes to become successful predators?

Which structure of the amniotic egg most closely surrounds the embryo?

Which of the following could be considered the most recent common ancestor of living tetrapods?

If a tunicate's pharyngeal gill slits were suddenly blocked, the animal would have trouble ________.

Unlike eutherians, both monotremes and marsupials

In what respect do hominins differ from all other anthropoids?