One of the biggest concerns, as the climate and environment around us changes, is the continuing decline of pollinators. In the UK, insect pollinators are estimated to be worth £430 million each year for their role in pollinating our crops. Research published last December provides strong evidence that temperature rises associated with climate change are negatively impacting on the relationships between plants and their pollinators.
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Most birds make nests, and spend their time foraging to feed and care for their chicks. Cuckoos, on the other hand, don’t waste their time with any of that, they simply lay their eggs in another bird’s nest and let them do all the heavy lifting. This might sound like the easy option, but in fact cuckoos have made a whole lot more work for themselves trying to evade and deceive their neighbours. When cuckoos succeed in their trickery, their unsuspecting host suffers, producing fewer young that year and wasting time and energy. So, evolution has pitted host birds against cuckoos, with each side developing increasingly sophisticated techniques to try and get their own way. Host birds mob potential attackers, while cuckoos use mimicry to avoid detection, and threaten defectors with serious consequences.
Cuckoos are famous for taking advantage of their unsuspecting neighbours; laying eggs in their nest and leaving their unwitting host to raise the chicks. The world cuckold, used to refer to the husband of an adulterous wife, originates from the cuckoo bird. There are over 50 species of parasitic cuckoo in the family Cuculidae; some are generalists who will lay their eggs in any available nest, others specialise in one or a few ‘host’ species, but all are engaged in an evolutionary battle with the species they parasitise – an arms race, if you will. Species parasitised by cuckoos are at a disadvantage – in the best case they are merely wasting resources raising an unrelated chick, in the worst case the chick will hatch early and push out the other eggs in the nest, meaning that the unlucky bird in question loses an entire clutch. In each generation, therefore, natural selection will favour host birds that are able to avoid parasitism. The birds might evolve to be more discerning, for example, identifying the appearance of cuckoo eggs and removing them, or selecting nest sites that are more difficult for the cuckoos to access. Equally, in each generation the cuckoos that are most successful in deceiving and parasitising their neighbours will produce more offspring and their traits will be favoured by natural selection. Cuckoos might evolve eggs that more closely resemble those of their host, or very rapid egg incubation to ensure their chick hatches first. Ultimately, neither species wins, with evolution demanding increasingly sophisticated tactics for successful parasitism in cuckoos, and traits to thwart parasitism in the host species.
Cats are one of the most common domesticated animal on Earth, with an estimated 400 million worldwide. And yet they lack many characteristics that tended to make animals good for domestication. They are solitary hunters, making them relatively poor at responding to and valuing social hierarchies. So how exactly did early humans domesticate our feline friends? Recent research suggests stroking and treats may have been key to winning them over.
Human activities are altering landscapes, dividing habitats and changing ecosystems. We rarely hear of any good coming from this, mostly because there isn’t. However, recent research has revealed an interesting evolutionary consequence of road construction for a small fish in the Bahamas. Over just 50 years of evolution, females in fragmented populations have exercised their preference to produce males that are better equipped to please them and more considerate of their feelings.
Humans are constantly modifying our landscape to make it more connected. We build roads, tunnels and bridges, we design boats and planes, all in an attempt to maximise our ability to move around. At the same time, these human structures are dividing ecological landscapes – our roads create barriers that keep many species from crossing and can have a significant impact on ecosystems. This is known as habitat fragmentation and it is one of the biggest concerns for biodiversity. Habitat fragmentation can split groups and isolate small, vulnerable or unviable populations. This can be a huge problem, reducing genetic diversity and leading to local or even global species extinction.
Symbiotic relationships, where two organisms ‘live together’ and rely upon each other to survive, are surprisingly common in the animal kingdom. The more we look, the more we find. What is less common, or at least less well documented, is the occurrence of speciation events within these partnerships. A recent study has revealed the first documented case of the speciation of a bacterial symbiont, inside the cells of a cicada. Even more interestingly, scientists believe it may have been little more than an evolutionary screw-up!
Symbiotic relationships can be quite casual, or extremely intimate, and are literally all around you. And inside you. The mitochondria inside your cells are symbiotic bacteria that joined our cells billions of years ago. Mitochondria show a pattern that is common in such intimate symbiotic relationships – over millions of years, partners in the relationship each have a reduced genome, with a complementary set of genes. This in turn makes them even more dependent upon each other. Mitochondria have only about 37 genes, compared to 1000 in a free-living bacteria. They simply don’t need many of their genes anymore because their host cells carry them. This is known as relaxed selection – because both members of the partnership carry the genes, a mutation in a gene in one partner will probably have no effect. The other member still has a functioning version of that gene, so the organism as a whole shows no negative symptoms, and natural selection is blind to the mutation. Only when both copies of a particular gene are degraded will natural selection step in, meaning that over time random chance will degrade complementary sections of each genome.
Have you ever had the “what would win in a fight” conversation with various different insect and arachnid combinations? Cockroach vs Mantis, Spider vs Scorpion, Ant vs Spider? Well, if you can think of it, nature has probably done it. True to form, I present you: Ant vs Spider, a battle being played out in Australian forests as we speak.
What can this squiggling, toothed eel-like creature possible tell us about our own brains? Well, the lamprey, although ugly, occupies a pivotal place in the evolutionary tree. Research on captive lampreys can tell us about the earliest evolution of the vertebrate brain and yield insights that may help to cure and treat neurological disease. A new study published in Nature last month suggests that the human pattern of development in an important region of our brains may have evolved much earlier than we thought, in a creature that looks much like a modern-day lamprey. So perhaps lampreys can tell us more about our brains than you might have thought!
Love it or hate it, sharing a bed with someone is the norm for most adults in a relationship, but how well we sleep together can have a profound effect on our mood, our relationships and the rest of our lives. A new study presented at a recent SLEEP conference suggests that sleeping couples sleep better together when the woman is more satisfied.
It has previously been reported that divorced and single people experience more sleep disturbances and generally poorer quality sleep than couples, but it seems that the quality of your relationship might also influence how well you sleep. Research presented at SLEEP 2014, the 28th annual meeting of the Associated Professional Sleep Societies, suggests that how well you sleep with your partner may be a reflection of the quality of your relationship. According to lead author Dr Heather Gunn from the University of Pittsburgh, “the sleep of married couples is more in sync on a minute-by-minute basis than the sleep of random individuals”, suggesting that our sleep patterns are influenced not just by where and when we sleep, but with also with whom we sleep.
Every night’s sleep is different, and how you sleep on any given night is likely to be determined largely by short-term causes – what and when you ate, how much exercise you did today, stress levels, what you watched on TV, whether your partner is snoring – but there are also fundamental, long-term differences between people in their sleep patterns. It is thought these differences are often genetic, and recent research supports this idea, identifying for the first time a gene involved in determining how much sleep we need.
Sleep is a huge part of our lives, and the lives of many animals. Although we still do not fully understand the strange phenomenon that takes up a third of our lives, it is clear that without it we cannot survive. But with a growing number of things keeping us awake – work, tv, friends, sport, buzzfeed, reddit – how much sleep is enough sleep?
Penguins are certainly one of the more cute and charismatic of the Antarctic fauna, but would people be so fond of penguins if they were over 2 metres tall? Fossils recently unearthed in Antarctica have revealed that giant penguins used to roam this icy continent.
Palaeeudyptes klekowskii, discovered on Seymour island off the Antarctic peninsula, was a penguin weighing 115 kilograms and towering above most people at 2m (6ft7). That’s two and a half times heavier, and nearly twice the height of an Emperor penguin (Aptenodytes forsteri)!