How to Answer IELTS Reading Identifying Writer's Claims Questions

The study and exploration of dinosaurs is included at one point or another in science curricula across schools in North America. Understanding these spectacular creatures sheds light on Planet Earth before humans came into existence and provides us with a fascinating look at prehistoric times. However, how comprehensive is our understanding of dinosaurs and the places in which they dwelled? Think about what you have heard, learned, or studied regarding dinosaurs and their habitats. When it comes to their dwellings, you are probably thinking of a humid swamp or an extremely hot forest. While certain dinosaurs most certainly lived in these types of environments for millions of years, scientists have found recent information that could contradict everything we seem to know about these creatures.

Would you be surprised to find out that Antarticta or Alaska were probable homes for dinosaurs? Just last year, paleontologists unearthed the remains of dinosaurs that were known to live in environments that were cold for most of the year. Rightly so, this discovery called for a thorough investigation and quite an open mind from the scientific community, as the findings had the potential to change our understanding of dinosaurs, or at least add an intriguing facet to the subject. Once the remains had been dug up and analyzed, paleontologists came to the conclusion that these creatures were known as “polar dinosaurs”, and endured long periods of dimly-lit environments for up to eight months! This has also provided further information regarding the initial stages of the Earth's changing climate. For instance, the “dimly-lit environments” during prehistoric times most likely occurred during a winter season, since it was generally the coldest period of the year.

However, these typical winters may have been much different from what current society is familiar with. In fact, they were most likely much milder than winters today. Scientists estimate that the typical winter in the area that we now come to regard as “Alaska” was closer to something that we may see in present-day Chicago. That is, there was plenty of ice and snow, but nowhere near what current temperatures in Alaska are known to be. Moreover, examining the temperature differences from these prehistoric winters and comparing them with what we experience today is a truly fascinating opportunity to understand how our climate has evolved.

Of course, fossils have played a large part in our understanding of dinosaurs, and continue to unleash excellent clues into prehistoric times. Unsurprisingly, they have also helped researchers link various relatives of dinosaurs together, ultimately providing more information regarding their habitats and probable locations.  Fossil evidence shows that the relatives of the popular Tyrannosaurus Rex would have roamed forests full of conifers, otherwise known as cone-bearing trees, which were similar to our modern day juniper or pine trees. These dinosaurs would have most likely hunted the thirty-five foot long herbivores, Edmontosaurs, in these forests. In this case, fossils have also verified information researchers had already speculated about when understanding the relationships between dinosaurs who acted as predators and those who met their ends as prey.

The changing temperatures and seasons forced dinosaurs to evaluate their habitats and make possible changes as to where they chose to dwell. For instance, when the winter season arrived, polar dinosaurs were faced with two options. First, they could stay where they were over the long winter, or escape to warmer climates. Scientists believe that the dinosaurs that stayed in a given area may have been warm-blooded, similar to modern birds and mammals, because they maintained a body temperature through metabolic processes. As this was considered quite a bold finding, it was met with criticisms and disbelief from the scientific community. Initially, some critics posited that these polar dinosaurs were most likely cold-blooded, remaining warm by absorbing sunshine. However, due to recent findings regarding the dimly-lit areas, this theory would be impossible, further proving the fact that these dinosaurs were warm-blooded.

Despite the initial contrary and popular belief, many paleontologists now agree that polar dinosaurs were warm-blooded. Looking at fossils has helped solidify this finding, and has unlocked more knowledge on not only prehistoric weather patterns, but on how these dinosaurs looked and roamed the land as well. For example, instead of working with projected models of fossils made of clay, paleontologists were finally able to base their findings off of real, physical fossils. This enabled them to truly understand the size and magnitude of dinosaur bones, especially in terms of their growth rates. Recently, these researchers were able to compare the dinosaurs' growth rates with those of both living and extinct animals, and found that the growth rate of the polar dinosaurs matched that of mammals. On the contrary, cold-blooded animals have shorter limbs and fewer degrees of muscle mass than warm-blooded animals. Thus, this fascinating discovery has made waves in the archaeological and paleontological world. Perhaps we will have to re-evaluate our knowledge of dinosaurs and their dwellings and revamp the way this is taught in schools!

The question of whether we are alone in the Universe has haunted humanity for centuries, but we may now stand poised on the brink of the answer to that question, as we search for radio signals from other intelligent civilisations. This search, often known by the acronym SETI (Search for Extraterrestrial Intelligence], is a difficult one. Although groups around the world have been searching intermittently for three decades, it is only now that we have reached the level of technology where we can make a determined attempt to search all nearby stars for any sign of life.

The primary reason for the search is basic curiosity - the same curiosity about the natural world that drives all pure science. We want to know whether we are alone in the Universe. We want to know whether life evolves naturally if given the right conditions, or whether there is something very special about the Earth to have fostered the variety of life forms that we see around us on the planet. The simple detection of a radio signal will be sufficient to answer this most basic of all questions. In this sense, SETI is another cog in the machinery of pure science which is continually pushing out the horizon of our knowledge. However, there are other reasons for being interested in whether life exists elsewhere. For example, we have had civilisation on Earth for perhaps only a few thousand years, and the threats of nuclear war and pollution over the last few decades have told us that our survival may be tenuous. Will we last another two thousand years or will we wipe ourselves out? Since the lifetime of a planet like ours is several billion years, we can expect that, if other civilisations do survive in our galaxy, their ages will range from zero to several billion years. Thus any other civilisation that we hear from is likely to be far older, on average, than ourselves. The mere existence of such a civilisation will tell us that long-term survival is possible, and gives us some cause for optimism. It is even possible that the older civilisation may pass on the benefits of their experience in dealing with threats to survival such as nuclear war and global pollution, and other threats that we haven't yet discovereIn discussing whether we are alone, most SETI scientists adopt two ground rules. First, UFQs (Unidentified Flying Objects) are generally ignored since most scintists don't consider the evidence for them to be strong enough to bear serious consideration (although it is also important to keep an open mind in case any really convincing evidence emerges in the future). Second, we make a very conservative assumption that we are looking for a life form that is pretty well like us, since if it differs radically from us we may well not recognise it as a life form, quite apart from whether we are able to communicate with it. In other words, the life form we are looking for may well have two green heads and seven fingers, but it will nevertheless resemble us in that it should communicate with its fellows, be interested in the Universe, live on a planet orbiting a star like our Sun, and perhaps most restrictively, have a chemistry, like us, based on carbon and water.

Even when we make these assumptions, our understanding of other life forms is still severely limited. We do not even know, for example, how many stars have planets, and we certainly do not know how likely it is that life will arise naturally, given the right conditions. However, when we look at the 100 billion stars in our galaxy (the Milky Way), and 100 billion galaxies in the observable Universe, it seems inconceivable that at least one of these planets does not have a life form on it; in fact, the best educated guess we can make, using the little that we do know about the conditions for carbon-based life, leads us to estimate that perhaps one in 100,000 stars might have a life-bearing planet orbiting it. That means that our nearest neighbours are perhaps 100 light years away, which is almost next door in astronomical terms.

An alien civilisation could choose many different ways of sending information across the galaxy, but many of these either require too much energy, or else are severely attenuated while traversing the vast distances across the galaxy. It turns out that, for a given amount of transmitted power, radio waves in the frequency range 1000 to 3000 MHz travel the greatest distance, and so all searches to date have concentrated on looking for radio waves in this frequency range. So far there have been a number of searches by various groups around the world, including Australian searches using the radio telescope at Parkes, New South Wales. Until now there have not been any detections from the few hundred stars which have been searched. The scale of the searches has increased dramatically since 1992, when the US Congress voted NASA $10 million per year for ten years to conduct a thorough search for extraterrestrial life. Much of the money in this project is being spent on developing the special hardware needed to search many frequencies at once. The project has two parts. One part is a targeted search using the world's largest radio telescopes, the American-operated telescope in Arecibo, Puerto Rico and the French telescope in Nancy in France. This part of the project is searching the nearest 1000 likely stars with high sensitivity for signals in the frequency range 1000 to 3000 MHz. The other part of the project is an undirected search which is monitoring all of space with a lower sensitivity, using the smaller antennas of NASA's Deep Space Network.

There is considerable debate over how we should react if we detect a signal from an alien civilisation. Everybody agrees that we should not reply immediately. Quite apart from the impracticality of sending a reply over such large distances at short notice, it raises a host of ethical questions that would have to be addressed by the global community before any reply could be sent. Would the human race face culture shock if faced with a superior and much older civilization? Luckily, there is no urgency about this. The stars being searched are hundreds of light years away, so it takes hundreds of years for their signal to reach us, and a further few hundred years for our reply to reach them. It's not important, then, if there's a delay of a few years, or decades, while the human race debates the question of whether to reply and perhaps carefully drafts a reply.