As teenagers, we probably associate with different people to those whose company we keep as adults. At one point in our lives, we may want subversive influences, while preferring support and stability at other times. The same is true for other partnerships in nature.
Take the whistling-thorn acacia. This African tree forms partnerships with four different species of ants. Some provide a valuable service as bodyguards (even routing elephants), while others have been written off as freeloaders and parasites. But Todd Palmer has found that these labels are too simplistic. In fact, none of the ants is a perfect partner. The tree actually does best by switching its alliances throughout the course of its life. At certain times, partnering with a parasite is actually its best course of action.
It’s the open ocean. A baby fish, less than a centimetre long, floats through the water, completely oblivious of the danger it is in. It’s caught in a current, but one so smooth that the fish cannot detect it. Its only clue to what’s happening comes too late, as it’s suddenly sucked into a ring of tentacles and swallowed by one of the ocean’s stealthiest predators – the sea walnut.
This is an arachnophobe’s worst nightmare: the largest spider web in the world. It belongs to the Darwin’s bark spider, which spins its gargantuan trap over entire rivers and lakes. Its shape – a simple ‘orb web’ – is normal enough, but its size is anything but. The main anchor thread that holds the web in place to both riverbanks can be as long as 25 metres and the main sticky core can be as large as 2.8 square metres.
With a web that big, it’s no surprise that Darwin’s bark spider uses the toughest silk of any species. It can resist twice as much force as any other spider silk before rupturing, and over 10 times more than a similarly sized piece of Kevlar. It’s not just the apex of spider silk – it’s the toughest biological material ever found.
In New Caledonia, an island off the eastern coast of Australia, a crow is hunting for beetle grubs. The larvae are hidden within a decaying tree trunk, which might seem like an impregnable fortress. But the New Caledonian crow is smarter than the average bird. It uses a stick to probe the tunnels where the grubs are sheltered. The grubs bite at intruders with powerful jaws but here, that defensive reflex seals their fate; when they latch onto the stick, the crow pulls them out.
This technique is not easy. Birds need a lot of practice to pull it off and even veterans can spend a lot of time fishing out a single grub. The insects are fat, juicy and nutritious but do they really warrant the energy spent on extracting them? The answer is a resounding yes, according to Christian Rutz from the University of Oxford. By analysing feather and blood samples from individual crows, he found that grubs are so nutritious that just a few can satisfy a crow for a day.
The patient known as P2 is just 18 years old, but he has been receiving monthly blood transfusions since the age of 3. P2 has a genetic disorder called beta-thalassaemia. Thanks to a double whammy of faulty genes, he can’t produce working versions of haemoglobin, the protein that allows red blood cells to carry oxygen around the body. Regular transfusions were the only things that kept him alive but for the last 21 months, he hasn’t needed them.
An international team of scientists have managed to partially correct his genetic faults, granting him his independence. It’s a major victory for gene therapy, the act of editing faulty genes within living cells in order to treat diseases.
In the body of a snail, a war is waging. It’s so violent that the only reason there isn’t blood everywhere is that the combatants don’t have any blood. The fighters are flatworms, simple parasites that have taken over the snail. Its body is now theirs, a shell in which they mate, cooperate, and produce more flatworms. But they don’t have it all to themselves – other colonies, and even other species of flatworms can invade the same snail. When that happens, war breaks out and the flatworms wage it with something more commonly associated with ants or humans – a caste of soldiers.
The natural world is full of great partnerships. Bacteria give animals the guts to digest all manner of otherwise inedible foods. Algae allow corals to harness the power of the sun and construct mighty reefs. Ants cooperate to become mighty superorganisms. But the greatest partnership of all is far more ancient. It’s so old that we can only infer that it took place by looking for signals of history, embedded into the genomes of modern species. The details of how and when it happened are still the source of fierce debate but this was undoubtedly the most important merger in the history of life on Earth: a partnership between two simple cells that would underlie the rise of every living animal, plant, fungus and alga.
I get a lot of emails. Most can be casually filed away, but among the spam and fluff from PR agencies, there are occasionally some absolute gems. And so it was that on August 21st, one Paul Sanders saw fit to send me four photos of a chicken.
Several months back, I wrote a piece about chickens that caught Paul’s eye. In a new paper, Mike Clinton’s group at the University of Edinburgh had found that these everyday birds have an amazing secret – every single cell in their bodies is either male or female. Each one has its own sexual identity, which is very different from the way that sex is determined in mammals.
You’ll have to read the original post for a full explanation of how this works, but the important bit is that Clinton’s discovery came about through studying three very unusual chickens called gynandromorphs. Each bird looks like it has been sown together from two different chickens down the midline; one half is clearly a cockerel and the other is clearly a hen. And that’s exactly what Paul Sanders found in his coop.