Evolution

The Evolutionary Origins of Coffee

15 September, 2014 by

Each second 26,000 cups of coffee are consumed globally. That’s over 93 million cups an hour, or an astonishing 2 billion cups a day! Why is coffee the most popular beverage on Earth? Well it might have something to do with all that lovely caffeine it contains. We are a species thoroughly addicted to caffeine; the most popular psychoactive substance in the world. Recent research into the genomics of the coffee plant is shedding some light on the evolutionary processes behind the world’s most popular drug, and revealing some of the reasons it is popular not just with humans, but with insects, too.

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Neanderthal Art

10 September, 2014 by

Neanderthals were once portrayed as unintelligent, uncultured brutes, but that picture is beginning to change. They are increasingly being viewed now as intelligent, cooperative creatures who performed cultural rituals and traditions and who mourned their dead. A discovery published in PNAS this year indicates they may have even had art. Art is considered to be one of the highest expressions of complex, abstract thought, and for a long time it was believed to be uniquely human (uniquely Homo sapien, that is).

Researchers excavating a cave in Gibraltar found an engraving on the rock wall in undisturbed ground alongside Neanderthal tools. The engraving from Gorham’s cave, which looks suspiciously like a hashtag, was placed prominently on the wall suggesting it may have been a message to visitors or intruders. There is no direct evidence, however, that the design actually means anything, but it seems likely it was intended to be seen. Interestingly, the engraving appears at a junction in the cave, where the cave changes direction by 90 degrees. It’s hard not to speculate that the design might therefore be intended to share some spatial information, a “You are Here”, perhaps. Likewise, it may have signalled that the cave was occupied.

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One Phage Cocktail, Please

10 June, 2014 by

Increasing antibiotic resistance is hitting the headlines at the moment, and a genuine concern is growing, amongst the public and scientists alike, over the concept of a future without antibiotics. Research attention is beginning to focus on possible solutions, but some may be old, rather than new.

In the second half of the 20th Century, patients suffering from bacterial infections behind the Iron Curtain were denied access to the antibiotics that were saving lives in the west. Instead, many of these people were treated with phage therapy, which makes use of viral bacteriophages which kill bacteria. Phage therapy never really caught on, however, at least in part because bacteriophages are highly specific (meaning you need to know exactly what has infected your patient to be able to treat effectively) and because people are inherently uneasy about treating an ailment using a virus. Interest has renewed recently however, in light of major concerns over antibiotic resistance, and the European Commission has just invested €3.8 million into a large-scale clinical trial of phage therapy.

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Extraterrestrial Intelligence: Friend or Foe?

19 October, 2013 by

Is Anybody Out there?

The universe is vast and ancient, containing billions of stars. The likelihood is that other Earth-like planets, suitable for intelligent life, exist out there. Given the vast amount of time available, some of these suitable planets should have evolved intelligent life, some of these lifeforms should have developed interstellar travel, which should in turn have enabled them to colonise the galaxy within just a few tens of millions of years. So, we should expect the universe to be teeming with intelligent life. Any yet, we find none. Despite 50 years of searching, we have not yet found any evidence of extraterrestrial civilisations. We have failed to detect artificial signals in space, and we have failed to find any artefacts of intelligent life. This is the basic tenant of the Fermi paradox; we expect intelligent life to be prevalent in the galaxy, and yet we are unable to find it.

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Selfish Strategies in Cooperative Society

10 March, 2013 by

Social insects show extraordinarily high levels of cooperation, giving up their reproductive opportunities and even sacrificing their own lives to save the colony. The social insect colony is a well-oiled machine, each part has its own key role to play, together forming an intelligent and adaptive society. Most people are familiar with the highly advanced social insects, such as honeybees and leaf cutter ants. Their societies are huge and intricate, and we have gained many fascinating insights from them. However, they tell us very little about how these societies evolved, or what it meant to be cooperative in a more primitive sense.

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Animal Personality Part II:
The Evolution of Personality

18 November, 2012 by

The field of research into personality and behavioural syndromes in animals has blossomed over the past few decades. With ample evidence for it’s existence, biologists have begun to consider its evolution; what is the adaptive benefit of personality? How are multiple personality types maintained in a population? Why do personalities exist when they sometimes result in maladaptive responses?

All these questions, and any evolutionary questions we might care to ask, make the assumption that personality is heritable. Without heritability, personality cannot be passed from generation to generation, and cannot be subject to natural selection. There is now plenty of evidence for high heritability of many personality traits in animals, although there is also an important influence of the environment too. Heritabilities estimates vary, from 0.22 – 0.61 in wild great tits, 0.32 in social spiders, 0.54 – 0.66 in humans and 0.2 – 0.8 in dumpling squid. These genetic influences may in part be reflected in brain morphology; one study in humans found differences in brain structure relating to neuroticism, conscientiousness, and extraversion. More neurotic people have a smaller total brain volume and a smaller frontotemporal surface area, whilst extraverts have a thinner inferior frontal gyrus.

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What Else Makes Us Human?
Fire

14 October, 2012 by

Over the last few months I’ve been discussing the characteristics that make us human, and which of the classic ‘uniquely human’ traits, really are ours and ours alone. But one aspect of human behaviour which I have not discussed so far is our use of fire. No other animal has learned to harness and control fire as humans have.

A recent discovery of wood ash along with animal bones and stone tools in a cave in South Africa suggests that humans may have used fire as early as 1 million years ago. This is around 300,000 years earlier than previously thought, and may indicate that earlier hominid species such as Homo erectus were using fire. Other tentative support for fire use by early hominids such as H.erectus and A.robustus have been found in South Africa and Kenya, possibly as early as 1.5 million years ago. Further evidence from Northern Israel in the form of burnt flint tools and plant remains indicates that H. erectusmay have been controlling fire around 800,000 years ago.

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The Social World of Slime

7 October, 2012 by

Social behaviour in animals is not uncommon, and we are rarely surprised to observe cooperation in nature. However, most explanations for cooperative behaviour rely upon a certain level of cognitive ability. Cooperating willy-nilly leaves individuals open to cheaters, so successful and long-term cooperation between individuals often relies upon individual recognition. Many social groups are composed of relatives. This makes a lot of sense, as helping relatives yields benefits without the need for reciprocation in the future, because relatives share genes. But still, you might expect that even this requires basic intelligence – you need to be able to recognise who are your relatives.

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Reasons Why Evolution is True Part X:
Convergent Evolution

23 September, 2012 by

When you design many objects that perform similar tasks, the logical strategy is to reuse the same design, perhaps with small modifications, for each object. There would be little point in coming up with a new design every time, right!? In nature, however, there are many species that do similar things but have arrived at their method through different designs. This is known as convergent evolution.

Intelligent design, and decent by modification, predict different patterns of similarities and differences between species. Evolutionary theory, which places all living things on a tree of relatedness, leads us to expect that species that are more closely related to each other should tend to be more similar. This is because they have both evolved from a recent ancestor. This ancestor has been ‘modified’ in various ways by natural selection to produce the two (or more) daughter species, but with a shared starting point for these modifications, we expect a fairly similar outcome. Traits that are shared between species due to shared ancestry are known as homologies. Homology has been the basis for determining relatedness between species (phylogeny) for hundreds of years. However, as early taxonomists noted, there are some occasions when species share traits despite the lack of a recent common ancestor. Often these species have reached a similar solution to a shared problem, despite being only very distantly related. This is known as convergence, and the more we look for it in nature, the more we find.

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What Else Makes Us Human?
Drug Use in the Animal Kingdom

18 September, 2012 by

Whilst writing the series on “What Makes Us Human?”, I started thinking about less obvious, less traditional ideas of what traits are truly human, and human alone. One characteristic occurred to me that seemed obviously to be unique to humans: recreational drug use. It seemed implausible that animals in the wild were indulging in drug abuse purely for their own entertainment, and I wondered if this could give some perspective on what it means to be human. But, as it turns out, I was wrong.

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