Exam 34: The Origin and Evolution of Vertebrates

Which of the following is the most inclusive (most general) group in which all of the members have fully opposable thumbs?

Marsupials survived in Australia (as opposed to Asia) because ________.

Ancient fossils that seem to be an intermediate stage in the evolution from fish to tetrapods had which of the following characteristics?

A team of researchers has developed a poison that has proven effective against lamprey larvae in freshwater cultures. The poison is ingested and causes paralysis by detaching segmental muscles from the skeletal structures. The team wants to test the poison's effectiveness in creeks flowing into major waterways, but one critic worries about potential effects on lancelets, which are similar to lampreys in many ways. Why is this concern misplaced?

Unlike eutherians, both monotremes and marsupials ________.

Fishes that have swim bladders can regulate their density and, thus, their buoyancy. There are two types of swim bladder: physostomous and physoclistous. The ancestral version is the physostomous version, in which the swim bladder is connected to the oesophagus via a short tube (see the figure). The fish fills this version by swimming to the surface, taking gulps of air, and directing them into the swim bladder. Air is removed from this version by "belching". The physoclistous version is more derived and has lost its connection to the oesophagus. Instead, gas enters and leaves the swim bladder via special circulatory mechanisms within the wall of the swim bladder. -If a ray-finned fish is to both hover (remain stationary) in the water column and ventilate its gills effectively, then what other structure besides its swim bladder will it use?

Why do adult urochordates (tunicates) lack notochords, even though larval urochordates have them? Larvae use notochords to ________.

Which of these might have been observed in the common ancestor of chondrichthyans and osteichthyans?

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

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. -The one-way flow of air along parabronchi makes what type of gas exchange mechanism possible, at least theoretically?

During chordate evolution, what is the sequence (from earliest to most recent) in which the following structures arose?

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

Chordate pharyngeal slits appear to have functioned first as ________.

Which of the following types of evidence would be useful in understanding if the impact of a comet caused the extinction of the dinosaurs?

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 metre tall) with small braincases (approximately 380 cubic centimetres) 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?

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

Fishes that have swim bladders can regulate their density and, thus, their buoyancy. There are two types of swim bladder: physostomous and physoclistous. The ancestral version is the physostomous version, in which the swim bladder is connected to the oesophagus via a short tube (see the figure). The fish fills this version by swimming to the surface, taking gulps of air, and directing them into the swim bladder. Air is removed from this version by "belching". The physoclistous version is more derived and has lost its connection to the oesophagus. Instead, gas enters and leaves the swim bladder via special circulatory mechanisms within the wall of the swim bladder. -Which shark structure is closest in function to a swim bladder full of gas?

Scientific views are based on evidence rather than an appeal to authority. Which of the following statements demonstrates a conclusion based on evidence?

Suppose you travelled back in time and located the first animals to have evolved feathers. You found that these animals were tree-dwelling ectotherms, able to run quickly but unable to fly. You also noticed that only males had feathers. Which hypothesis of feather evolution would these data most support? Feathers initially evolved in a role associated with ________.

Living vertebrates can be divided into two major clades. Select the appropriate pair.