IELTSwithJurabek

PASSAGE 2

Read the text and answer questions 14-26

How do plants talk to each other?

Research shows that plants communicate and interact with each other in surprisingly subtle and sophisticated ways

14 In 1983, plant scientists Jack Schultz and Ian Baldwin reported that healthy young maple trees increased their defense systems when exposed to maples that had been damaged by plant-eating (herbivorous) insects. The injured trees, they suggested, were alerting neighbors to the presence of a predator by releasing chemical signals into the air. But the plant research community did not accept this. The results were difficult to replicate, critics pointed out. Many also questioned how a trait could be evolutionarily stable if it benefited neighboring plants but not the plant releasing the signal. By the late 1980s, most ecologists felt that Schultz and Baldwin's ideas had been discredited.

15 A decade later, however, a number of more carefully designed experiments began to yield convincing indications to the contrary. In 2000, evolutionary ecologist Richard Karban showed that wild tobacco plants became resistant to herbivores when grown in close proximity to sagebrush plants whose leaves had been damaged by cutting. This change appeared to be in response to chemicals - known as volatile organic compounds or VOCs - released by the sagebrush plants. Other researchers soon reported similar VOC-induced defense responses in several other plants, including lima bean, broad bean, barley, and corn. And in 2006, Karban showed that VOCs released by damaged sagebrush induce herbivore resistance in plants growing at distances of up to 60 cm, well within the range of sagebrush neighbors in nature.

16 But the question still remains: "Why should a plant waste valuable resources on a function which has no obvious advantage for it?" One hypothesis is that external communication channels are merely an extension of within-plant signaling. In sagebrush, lima bean, and poplar, VOCs released from damaged parts of a plant induce resistance in intact sections of the same plant, suggesting that each individual plant uses the signals to coordinate its own physiological responses to protect itself. Karban agrees, saying, "The interplant signaling we see may be a result of plants co-opting that process." Alternatively, VOC-based signaling between plants may have been favored because it enhances the "extended fitness" of the sender by aiding related plants of the same species: a strategy known as kin selection.

17 Over the past few years, a team led by Ariel Novoplansky of Ben-Gurion University of the Negev in Israel seems to have found proof that distress signals can be passed through the plants' roots. They planted garden pea plants in rows and subjected the first in each row to conditions similar to those experienced in a drought. They then evaluated the response by measuring the microscopic holes on leaves, known as pores, which react when there is a shortage of water. After fifteen minutes, the stressed plant was seen to be closing its pores, followed by all of its neighbors, one by one. Importantly, in a control setup where root contact between neighboring plants was blocked, pores stayed open. Meanwhile, David Johnson's team at the University of Aberdeen in Scotland have been studying the labyrinths of hair-like fungi that occur around the roots of most plants. These fungi are involved in an important two-way relationship: in exchange for sugars, they provide plants with much-needed phosphorus and nitrogen. Research in which broad bean plants were infested with aphids - small herbivorous insects - revealed that these networks also served as a channel for warning neighboring plants of the infestation.

18 Monica Gagliano of the University of Western Australia believes that plants may even use sounds to alert their neighbors. In one study, she demonstrated that chili plant seedlings grown next to fennel plants developed more quickly than seedlings grown with other chili plants. Gagliano and her colleagues suspect the chili plants were compensating for the presence of the fennel, which is known to release chemicals that inhibit the growth of other plants. Remarkably, however, all known plant communication pathways - airborne volatiles, root contact, and common fungal networks - were blocked. The results begged for an alternative explanation. "We think this other channel of communication might be acoustic," says Gagliano. But behavioral ecologist Carel ten Cate of the University of Leiden in the Netherlands points out that taking advantage of such benefits would require sensory mechanisms yet to be described in plants. Despite widespread skepticism, Gagliano has received some encouragement. Richard Karban, for example, is cautiously enthusiastic. "Whether or not the explanation she favors is the right one," he says, "I think that she's gotten results that, as a field, we need to come to grips with."

19 Researchers believe that knowledge of this phenomenon would actually be applied to agriculture, and lead to the cultivation of hardier crops. They all agree that there is still much work to be done. "Applying our limited knowledge [of plant-communication mechanisms] to agriculture is a big jump," says Johnson, "but it is definitely on the horizon." Nevertheless, one message has emerged loud and clear from those studying this new realm of botanical interaction: despite not possessing eyes, ears, or a nervous system, plants are anything but uncommunicative. "When I did my PhD [in the late 1980s], all this stuff was considered very weird," recalls Ariel Novoplansky. "Today, there's no doubt. We now recognise that plants are capable of some very sophisticated exchanges of information with other plants. This idea is not strange anymore."

PASSAGE 3

Read the text and answer questions 27-40

Star Performers

Most organisations are looking for talent. But what if they've got it wrong, asks Jeffrey Pfeffer

A One widely held assumption about talent is that it is a reasonably fixed characteristic and it is therefore the job of organisations to identify, recruit and retain star performers. This belief affects the way people are managed in the workplace. Most recruitment decisions are influenced by the skills and abilities of an individual rather than their aptitude and attitude. In terms of career development, organisations invest in staff who have been selected to reach higher-level positions, while ignoring front-line employees and people with less perceived potential. This idea, that talent is a fixed, identifiable characteristic - and that those firms with the best people do the best - is both flawed and harmful to people and organisations. There is a lot of evidence on this point, and it is useful to highlight some of the most pertinent arguments.

B First, are there stars? There is no question that in every field, from sports to computer programming to music, there are people who are better than the rest. As psychologist Dean Keith Simonton, who has spent his career studying greatness, has said, "Wherever you look, the same story can be told. Identify the ten per cent who have achieved the most in a certain endeavour. Count the accomplishments they have to their credit. Now tally the accomplishments of the remaining 90 per cent.

The first tally will equal or surpass the second." For instance, in music, 16 individuals have produced about 50 per cent of the Western classical music that is performed and recorded today, while another 235 composers have produced the remaining half. The more interesting questions concern not the existence of stars, but whether these stars can be reliably identified and, even more importantly, whether their talent is a fixed aspect or can be altered.

C Identifying the best people is tricky. Quality of performance changes over time and this is true whether we are talking about professors or footballers. If performance naturally varies, any measurement taken at a single point in time, such as when someone is being hired, will have error and imprecision. Therefore, single assessments of talent are likely to contain mistakes in their categorisation of people. Also, judgements about performance and ability depend on the standards used to judge what is good and bad. It should surprise no-one that for Bach to be considered a great musician, standards of music needed to change to embrace the qualities that his compositions possessed. Similarly, artists and art come in and out of fashion, which means that what is genius depends not only on a person's ability, but on the prevailing standards used to evaluate output.

D Finally, it is difficult to evaluate people and their abilities with precision. In the domain of work, research shows that the best predictors of job performance tend to be measures of intelligence. But even these measures correlate only loosely with performance, which means that more than 80 per cent of the variation in performance is unexplained by even the best predictors. Even in the sports arena, where one would think natural ability would be readily assessed because sports teams spend lots of resources on identifying talent, mistakes get made. Basketball star Michael Jordan was dropped by his high-school basketball coach and a number of top American football quarterbacks were available early in their careers because they were not considered good enough by various teams.

E This leads on to the next question: is talent born or made? Should organisations assume that almost anyone can become a star performer, which implies that there ought to be a greater emphasis on motivation and development, or do they just figure out who is good and who isn't? Here the evidence is clear: talent is at least as much "created" as inherent and, more importantly, the customary way companies think about identifying talent almost certainly works to destroy a lot of untapped potential.

Decades of research by K Anders Ericsson, professor of psychology at Florida State University, show that exceptional performance doesn't happen without around ten years of nearly daily, deliberate practice for about four hours a day, by people who with the assistance of their coaches have access to the best techniques. Once achieved, exceptional performance can't be maintained without relentless effort. So performance may be as much a consequence of training as it is of innate ability, which suggests that performance can be altered by how people are managed.

F Further research by Stanford psychology professor Carol Dweck shows that the tendency of organisations to see performance results as an opportunity for an "assessment" of ability, results in lower performance and poor motivation. Dweck identified two sets of goals that people bring to a performance context: "performance goals, where the purpose is to validate one's ability or avoid demonstrating a lack of ability, and learning goals, where the aim is to acquire new knowledge and skills".

People with performance goals have been shown to be more prone to helpless behaviour and debilitation after a setback, while people with learning goals strive for higher performance. The implications for managing people and talent are clear. Seeing talent as fixed and job performance as a way of classifying people creates a self fulfilling prophecy in which ability and intelligence do become fixed. By contrast, seeing ability as malleable leads to a different sort of self-fulfilling prophecy, in which individuals and their employers may invest in ways to enhance performance.