If you have ever wondered what the oldest living animal is or why childbearing is so difficult, the answers can be found in a new exhibition in Bern.
"C'est la Vie" – French for "That's Life" – draws on the four million or so items at the city's Natural Science museum to explore what life is all about.
Not that it offers a definitive answer to the most basic question of all. "Strictly speaking, it is impossible to make an absolute razor-sharp distinction between Life and Not-Life," it warns.
It also points out that although we know the prerequisites for life, how life actually started is still a mystery.
But visitors are invited to use their senses of sight, smell and hearing to discover the extraordinary variety of life today. Films, video and audio installations as well as imaginative models offer something for everyone, however much or however little they know.
"We have a very broad audience," museum director Marcel Gunter told swissinfo. "Families with children are the main part of our public, but everyone can pick out something that is interesting for them."
Gunter admitted that the most difficult thing was deciding what to put in and what to leave out. In the end the designers settled on three themes: "Beginning and end", "Pas de deux" and "The world in the head".
No life without death
The first section is devoted to life and death. It shows how the two are intricately linked.
Part of the exhibition's definition of life is that all living things die. And as part of the cycle of life, dead bodies are broken down and disposed of by living organisms.
This is where you learn that the oldest living animal is a glass sponge living in the Antarctic. They are thought to live for up to 10,000 years. That's a hundred times longer than a whale, and thousand times longer than the common earthworm. But would you have guessed that the worm lives more than three times as long as the mouse?
The museum is a repository of dead animals, and this section pays tribute to some of its collectors and their collections. Visitors can peer through a transparent floor onto treasures from another age: stuffed flamingos, neatly folded and laid in a case; spiky shells, smooth shells, shells the size of a human head, shells not much bigger than a grain of sand; the armour of long-dead armadillos...
But what's a Rolling Stone doing here? Meet the wasp, Pteromalus briani, discovered near Bern on the birthday of the late Stones guitarist Brian Jones by a member of the museum staff, a keen Stones fan. Collecting and naming are a little-known but vital part of the function of natural history museums.
The mating game
Living things reproduce, passing their characteristics on to the next generation. That's another definition of life, so it is logical that the exhibition focuses on this aspect too.
A whale gives birth to about ten calves in 30 years; a turtle lays about 4,000 eggs. But both can expect to have roughly the same number of adult offspring. The difference lies in the amount of care the mother gives.
It's all a matter of balancing risk and benefit. The mating displays of some birds are a good example: the male bird showing off his finery may attract predators as well as an appreciative female and his elaborate plumage may make it hard to fly.
Risk and benefit is also why human childbirth is so difficult. Our big brains are what give us our advantage, but a big brain means a big head. We long ago found it useful to walk upright, but that altered the angle of the pelvis. The human baby, big head first, has to change direction as it inches its way down a complicated birth canal.
No wonder that humans take such care of their offspring born with such difficulty. But it's not easy being a parent: each child needs about 6,000 changes of nappy, asks 20,000 questions, and has to be told 2,000 times to tidy up its room, one showcase informs us.
Who am I?
The "World in the Head" section looks at the senses and the brain. An ingenious animation featuring a computer mouse and a row of handbags illustrates some of the senses humans don't have. Sharks, for example, can detect the electric field of their prey, while snakes have warmth sensors for the same purpose.
The brain itself is built of nerve cells, making its owner aware of its surroundings and able to react to them. But the owner of a complex brain can do far more: learn, recognise things, master new situations and see connections.
The human brain with its 100 billion cells is in many ways still a puzzle to scientists. But organisms with much simpler brains can help them investigate different aspects of how the brain works. The California sea slug, with only about 20,000 nerve cells, is giving new insights into memory; the zebra fish is providing information about blindness and deafness and right- and left-handedness.
Full of mysteries, full of wonders, full of variety – that's life!
swissinfo, Julia Slater
Bern's Natural History Museum
The museum was founded in 1832.
It works in close collaboration with Bern University.
It has nearly four million items in its collection, of which 3,409,000 are invertebrates, including 1,300,000 snails.
Its most famous exhibit is the St Bernard dog, Barry, famed for his many rescues.
It attracts over 100,000 visitors annually.
About a fifth of its display area is devoted to a long-term temporary exhibition.
C'est la Vie is scheduled to run until about 2015.
The target is both children and adults: it aims to be challenging, surprising and informative.
""Strictly speaking, it is impossible to make an absolute razor-sharp distinction between Life and Not-Life."
"Whatever obtains energy from light or food, reacts to its environment, grows, is able to pass its characteristics on to the next generation, is one individual among many similar individuals and can die, is certainly alive."
"Life comes from life."