Summing Up Science With Headlines Quiz

Answer: Asteroid Killed Dinosaurs

Of the various theories for how the reign of the dinosaurs came to an end, the asteroid theory seems to be supported by the greatest amount of evidence. One major finding (and that which is referred to in the question) was that a thin layer of clay lying between the cretaceous and the tertiary rock strata contained abnormally high levels of iridium.

This became known as the K-T boundary, owing to the single letter designations for these two geological periods (cretaceous is designated K rather than C since C designates the carboniferous period).

Whilst iridium levels on Earth are very low, they are much higher in asteroids, and it was thought that the vaporised rock formed upon impact had settled to become the K-T boundary, as described by Luis Alverez and his son Walter. Furthermore, an impact site consistent with the size and age of such an asteroid had also been identified - Chicxulub crater in Mexico.

Answer: God Particle Found

Few things in science have enjoyed as much media attention as the Higgs boson, yet few scientific subjects in the media are understood as poorly by the general public. At its most basic level, the Higgs boson (or God Particle, as it was described in the 1993 book "The God Particle: If the Universe Is the Answer, What Is the Question?") explains why fundamental particles such as electrons have mass. Immediately after the Big Bang, fundamental particles were believed to have been weightless, and so moved at the speed of light. Shortly after the initial "bang", it was theorised that the Higgs field developed, introducing a drag on these particles, slowing them down. Meanwhile, the photon, which has no mass, was not affected by the Higgs field and so continued to travel at the speed of light (indeed it has been proposed that the photon may even be able to exceed this speed).

The Higgs field was proposed to be made up of once theoretical particles called Higgs bosons, the existence of which were confirmed in 2013, almost fifty years after they were first proposed.

Answer: DNA Structure Solved

Two British-based groups are often credited with the discovery of the structure of DNA - the famous double helix (or twisted ladder). One group was based in Cambridge and included the experienced Francis Crick and the young and self-confident James Watson.

The second group was based at King's College, London, and was led by Maurice Wilkins. Wilkins was later joined at King's by Rosalind Franklin, a sharp but acerbic scientist who specialised in X-ray crystallography. This rather arcane field seems daunting, but was the key to the discovery of the structure of DNA and remains the leading method for structural analysis of proteins (a rapidly developing area of study).

At the same time, Linus Pauling was working on the structure of DNA in America. Pauling was a giant in the field of structural biology and when he announced he had discovered the structure of DNA, the British groups felt resigned.

However, it soon became clear that Pauling's triple helix model did not fit with the excellent X-ray images of Rosalind Franklin.

It is unjust that, despite it being her images that led to the development of the double helix model, Rosalind Franklin is often written out of the history books. Some put this down to sexism (which may have some truth), but it may also be due to her passing away before the Nobel Prize was awarded to Crick, Watson, and Wilkins.

Answer: Scientists Cheat Death

This statement seems fantastical, and indeed it is! The field of ageing is poorly understood in biology and the link between steroid hormones and ageing seems much more complicated in humans than in C. elegans. Despite this, the link between these hormones (in particular estrogen) and ageing can be justifiably described as exciting, if not amazing.

It is thought that estrogen competes with insulin receptor substrate (IRS) for insulin receptors. IRS are implicated in the production of free radicals known as reactive oxygen species which have been directly linked to ageing.

Therefore, by blocking IRS signalling, estrogen prevents ageing of cells. Estrogen signalling has also been linked with repair. In mouse models lacking specific estrogen receptors, wounds heal much more slowly than in mice with fully functioning receptors.

The anti-ageing role of estrogen is easily relatable to humans - the menopause is associated with a sharp fall in estrogen levels, which parallels the development of age-related disorders such as osteoporosis. Conversely, pregnant women (who possess incredibly high levels of estrogen) heal at a rate that would make X-Men's Wolverine jealous. Estrogen therefore functions on several levels, but few of which are completely understood. Further research in this field could lead to the anti-ageing therapeutics that so many desire.

Answer: Earth-like Planet Found

Earth-like planets, or planets which potentially harbour life, are invariably judged on whether or not they possess liquid water. Water, like many other molecules, can be detected by spectral analysis. It is true that life on Earth is dependent on water. Water keeps cells turgid, preventing them from shrivelling and dying. Water assists the hydrophobic effect which allows cell membranes to form and proteins to fold. Water is utilised in many enzymatic reactions that are essential to our survival.

It is also true that water has many unique qualities - it has a high heat capacity (meaning it is fairly thermostable), it is colourless (allowing photosynthesis of underwater plants), and it demonstrates cohesiveness (allowing water to move up the stems of plants) - but can other substances carry out the same function as water? Do we only utilise water in the ways we do because it was abundant at the time of the birth of life? If the answer to either of these questions is "yes", the search for extra-terrestrial life can be extended to planets which possess no water. If indeed this life did exist, would we recognise it as life?

Answer: Fermat's Last Theorem Solved

Fermat's last theorem states that, while there are infinite whole number solutions to the Pythagorean equation x^2 + y^2 = z^2, there are no three positive integers capable of satisfying the same equation when the integers are raised to any power greater than 2.

A trifle curiously, Fermat claimed to have mathematical proof of this, but failed to leave any note of it in his works. For centuries, the problem remained unsolved, and seemed so out of grasp that it was referred to as the "world's hardest mathematical problem". Several groups and individuals produced work which would be useful to the eventual solution of this theorem, such as Yatuka Taniyama and Goro Shimura, whose theorem stated that every elliptic curve is modular.

This theorem also lacked mathematical proof and it became apparent that solving this theorem would effectively solve Fermat's last theorem.

The man behind the proof was Andrew Wiles, who worked in isolation and secrecy for seven years before announcing that he had solved Fermat's last theorem - something he had described as a childhood dream.

The news that Wiles had made a mistake in his proof brought an unwelcome and intense spotlight on him (and others) to race to resolve the problem. The issue was resolved by Wiles in 1994, just one year after the problem was identified.

Answer: Atoms Are Mainly Space

The famous experiment known as the Rutherford experiment (or perhaps more accurately the Geiger-Marsden experiment, since it was carried out by these two scientists, under the supervision of Rutherford) was carried out in the University of Manchester early in the 20th century and overturned the Plum Pudding model of the atom, which was the prevailing theory of the time and was put forward by J. J. Thompson, discoverer of the electron. Alpha particles are another name for helium nuclei (two neutrons and two protons) and have a 2+ charge. These particles were fired at a thin gold foil and it was demonstrated that most passed through the foil, suggesting that an atom was mostly empty space. Very few of the alpha particles were deflected, suggesting a concentrated positive nucleus. This contributed to the current model of the atom - a dense positive nuclei with electrons whizzing round in orbitals.

Rutherford is still a big name on the Manchester campus, and he gives his name to a prize awarded to students and staff for outstanding contributions to the university.

Answer: Missing Link Found

The specimen referred to in the question is Darwinius massillae, more commonly known as Ida. This fossil was unearthed in 1983, but the storm of media attention was somewhat delayed, perhaps due to the time taken to properly study and authenticate the fossil. Though her body proportions are very similar to that of a lemur, Ida displays a talus bone more similar to apes and monkeys than lemurs, and lacks the "toothcomb" and "grooming claw", thus distinguishing them from members of the suborder Strepsirrhini (such as lemurs).

Throughout this quiz, some buzz phrases have been more accurate and appropriate than others. For example, "DNA Structure Solved" is accurate and is not hyperbole. "God Particle Found" is also accurate, if perhaps a little fantastical. "Asteroid Killed Dinosaurs" is a little different - it is clearly the correct answer based on the information provided in the question, but it is not a universally accepted truth. The buzz phrase of this question - "Missing Link Found" - is one of the most common in evolutionary biology, but is a largely meaningless phrase used to placate anti-evolutionary types (which it fails to do). Firstly, it shows a fundamental lack of understanding in how evolution works, Evolution is not a series of distinct specimens, but is a gradual (and often painfully slow) process in which each specimen is so slightly different from that which precedes it so as to be indistinguishable. Secondly, fossils are vanishingly rare. Dinosaurs walked the Earth for 135 million years and the rarity of their fossils gives an indication of how few hominid fossils there are (even Australopithecus afarensis - one of the most ancient hominids - lived only 3.9 million years ago).

Answer: Big Bang Theory Proven

Cosmic microwave background radiation is a remnant of radiation released early in the development of the universe. It is thought that a time known as the "Recombination Era" followed the Big Bang and saw the universe cool to a sufficient temperature to allow electrons and protons to (re)combine to form hydrogen atoms.

This process also released high energy radiation that, if the expanding universe theory were true, would now exist close to the microwave range. This was serendipitously found to be the case by Arno Penzias and Robert Wilson.

The signal they were picking up was originally seen as an annoyance and was even thought to be due to pigeon droppings. The signal proved to be the predicted cosmic microwave background radiation and earned Penzias and Wilson the 1978 Nobel Prize in Physics.

Answer: Superbug Discovered

Following the serendipitous discovery of penicillin in the 1920s, the antibiotic began to be produced on a large scale and proved to be somewhat of a panacea. So much so, in fact, that by the late 1960s Dr. William H. Stewart (then US Surgeon General) declared that "it is time to close the book on infectious diseases". This statement proved premature as bacterial strains such as MRSA began to evolve a resistance to antibiotics (MRSA stands for Methicillin Resistant Staphylococcus Aureus). It is an interesting observation that these resistant strains almost certainly would not have become prominent had it not been for our profligate use of antibiotics. A random mutation which confers resistance to an antibiotic is likely to slow the growth of bacteria and so is unfavourable in normal circumstances. This trait becomes favourable in the presence of antibiotics, however - despite their slower rate of reproduction, these mutant bacteria survive whilst others die, and soon become the dominant "version" of this bacterial strain.

We are therefore entering an arms race with bacteria. One way to get round the problem of antibiotic resistance is to develop new antibiotics. Also, cocktails are used on the premise that it is unlikely that bacteria will evolve resistance to several antibiotics (though this has occurred in strains such as MRSA).