The evolution of intelligence among early large mammals of the grassla

Question

The evolution of intelligence among early large mammals of the grasslands was due in great measure to the interaction between two ecologically synchronized groups of these animals, the hunting carnivores and the herbivores that they hunted. The interaction resulting from the differences between predator and prey led to a general improvement in brain functions; however, certain components of intelligence were improved far more than others.

The kind of intelligence favored by the interplay of increasingly smarter catchers and increasingly keener escapers is defned by attention — that aspect of mind carrying consciousness forward from one moment to the next. It ranges from a passive, free-floating awareness to a highly focused, active fxation. The range through these states is mediated by the arousal system, a network of tracts converging from sensory systems to integrating centers in the brain stem. From the more relaxed to the more vigorous levels, sensitivity to novelty is increased. The organism is more awake, more vigilant; this increased vigilance results in the apprehension of ever more subtle signals as the organism becomes more sensitive to its surroundings. The processes of arousal and concentration give attention its direction. Arousal is at frst general, with a flooding of impulses in the brain stem; then gradually the activation is channeled. Thus begins concentration, the holding of consistent images. One meaning of intelligence is the way in which these images and other alertly searched information are used in the context of previous experience. Consciousness links past attention to the present and permits the integration of details with perceived ends and purposes.

The elements of intelligence and consciousness come together marvelously to produce different styles in predator and prey. Herbivores and carnivores develop different kinds of attention related to escaping or chasing. Although in both kinds of animal, arousal stimulates the production of adrenaline and norepinephrine by the adrenal glands, the effect in herbivores is primarily fear, whereas in carnivores the effect is primarily aggression. For both, arousal attunes the animal to what is ahead. Perhaps it does not experience forethought as we know it, but the animal does experience something like it. The predator is searchingly aggressive, inner-directed, tuned by the nervous system and the adrenal hormones, but aware in a sense closer to human consciousness than, say, a  hungry lizard’s  instinctive snap at a passing beetle. Using past events as a framework, the large mammal predator is working out a relationship between movement and food, sensitive to possibilities in cold trails and distant sounds — and yesterday’s unforgotten lessons. The herbivore prey is of a different mind. Its mood of wariness rather than searching and its attitude of general expectancy instead of anticipating are silk-thin veils of tranquillity over an explosive endocrine system.    1 
 1. The author refers to a hungry lizard ( Highlighted ) primarily in order to

A. demonstrate the similarity between the hunting methods of mammals and those of nonmammals
B. broaden the application of the argument by including an insectivore as an example
C. make a distinction between higher and lower levels of consciousness
D. provide an additional illustration of the brutality characteristic of predators
E. offer an objection to suggestions that all animals lack consciousness

2  
 2. It can be inferred from the passage that in animals less intelligent than the mammals discussed in the passage

A. past experience is less helpful in ensuring survival 
B. attention is more highly focused 
C. muscular coordination is less highly developed 
D. there is less need for competition among species
E. environment is more important in establishing the proper ratio of prey to predator 
 
 3  
 3. According to the passage, improvement in brain function among early large mammals resulted primarily from which of the following?

A. Interplay of predator and prey 
B. Persistence of free-floating awareness in animals of the grasslands
C. Gradual dominance of warm-blooded mammals over cold-blooded reptiles
D. Interaction of early large mammals with less intelligent species 
E. Improvement of the capacity for memory among herbivores and carnivores

4  
 4. According to the passage, as the process of arousal in an organism continues, all of the following may occur EXCEPT

A. the production of adrenaline 
B. the production of norepinephrine 
C. a heightening of sensitivity to stimuli 
D. an increase in selectivity with respect to stimuli 
E. an expansion of the range of states mediated by the brain stem

Sajjad1994 · Answer

OE

1. The author refers to a hungry lizard (     Highlighted     ) primarily in order to

Explanation

Choice C  is correct. The  “hungry lizard’s instinctive snap”  is contrasted with the mammal’s higher level of awareness.  Choices A  and  B  are incorrect. The example of the hungry lizard provides a contrast; it does not demonstrate a similarity or extend the author’s argument.  Choices D  and  E  are incorrect. Brutality is not mentioned in the passage as a characteristic of predators, and there is no suggestion that all animals lack consciousness. 
  
  Answer: C

Sajjad1994 · Answer

OE

2. It can be inferred from the passage that in animals less intelligent than the mammals discussed in the passage

Explanation

Choice A  is correct. The author defines intelligence in terms of an animal’s use of past experience. In the context of the entire passage, it can be inferred that more intelligent animals, such as the grassland mammals discussed, are better able to use past experience to help them survive than less intelligent animals are.

Choice B  is incorrect. The second paragraph of the passage indicates that attention is more highly focused in animals of greater, rather than less, intelligence.

Choices C, D,  and  E  are incorrect. The author does not discuss muscular coordination as an element in intelligence, gives no indication that in less intelligent species there is less need for competition, and does not discuss how a proper ratio of prey to predator is established.

Answer: A

Sajjad1994 · Answer

OE

3. According to the passage, improvement in brain function among early large mammals resulted primarily from which of the following?

Explanation

Choice A  is correct. It directly paraphrases the statement in lines 3—5, which describes the author’s view of the development of improved brain function in early mammals.

Choice B  is incorrect. It is likely that the persistence of  “freefloating awareness”  played a part in the animals’ survival, but there is no indication in the passage that brain function improved because of it.

Choices C  and  D  are incorrect: the passage does not discuss the relationship between mammals and reptiles or the interaction between large mammals and less intelligent species.

Choice E  is incorrect. Improved capacity for memory is an improvement in brain function, rather than a reason for improved brain function. 
 
  Answer: A

Sajjad1994 · Answer

OE

4. According to the passage, as the process of arousal in an organism continues, all of the following may occur EXCEPT

Explanation

This question asks you what does NOT occur during arousal. To answer the question, you must first determine what does occur. According to the passage, arousal does stimulate the production of adrenaline and norepinephrine; does increase sensitivity to stimuli; and does increase concentration on specific stimuli. Thus  Choices A  through  D  all describe consequences of arousal. Only  Choice E  is correct. There is no indication in the passage that the range of states mediated by the brain stem expands during arousal. 
 
  Answer: E

The evolution of intelligence among early large mammals of the grassla

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards