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. Species Australopitheaus afarensis A. africanus Paranthropus boisei Homo habilis H. ergaster H. erectus H. heidelbergensis H. neanderthalensis H. floresiensis H. sapiens Location of Fossils Africa Africa Africa Africa Africa Africa, Asia Africa, Europe Middle East, Europe, Asia Asia Middle East, Europe, Asia Estimated Average Body MLass (kg) 450 450 510 550 850 1000 1200 1500 380 1350 Estimated Average Body MLass (kg) 36 36 44 34 58 57 62 76 16-36 53 Associated with Stone Tools? No No No? yes yes yes yes yes yes yes The table is a comparison of several characteristics of H. floresiensis to those of nine other hominin species (arranged roughly from oldest to most recent). What do these data suggest?

The evolution of similar insulating skin coverings such as fur, hair, and feathers in mammals and birds is a result of ________.

Which of the following is a characteristic of all chordates at some point during their life cycle?

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

Use the following figure and information to answer the question. 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 esophagus 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 esophagus. 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?

The earliest known mineralized structures in vertebrates are associated with ________.

Chordate pharyngeal slits appear to have functioned first as ________.

It is believed that the coelacanths and lungfish represent a crucial link between other fishes and tetrapods. What is the major feature in these fish in support of this hypothesis?

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

Mammals and birds eat more often than reptiles. Which of the following traits shared by mammals and birds best explains this habit?

Which of these are amniotes?

Use the following figure and information to answer the question. 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 esophagus 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 esophagus. 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?

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 ________.

Which of the following are the only extant animals that descended directly from dinosaurs?

Arrange the following taxonomic terms in order from most inclusive (most general)to least inclusive (most specific).

Which of the following represents the strongest evidence that two of the three middle ear bones of mammals are homologous to certain reptilian jawbones?

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

Which clade does not include humans?

Use the following figure and information to answer the question. 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 esophagus 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 esophagus. Instead, gas enters and leaves the swim bladder via special circulatory mechanisms within the wall of the swim bladder. The presence of a swim bladder allows the typical ray-finned fish to stop swimming and still ________.

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