Bob and Kate sit down in their favourite restaurant and examine the menu. Today is Kate's birthday, so they are treating themselves to something special. But what will it be? The pterodactyl p'te sounds tempting - but so do the brontosaurus burger and the stegosaurus stew. And then there is the chef's special: diplodocus pie. So hard to choose!

In recent years food companies have invested heavily in products that will appeal to meat-eaters without causing suffering to animals. People concerned about climate change recognise the huge amount of damage done by the beef industry in particular. But for many, giving up meat is easier said than done.

"Eating meat is in our DNADeoxyribonucleic acid is the material in an organism that carries genetic information.," writes Annie Lowrey, a vegetarian journalist, in The Atlantic. "One prominent scientific theory even holds that meat-eating made us Homo sapiensThe species to which all modern humans belong. Homo sapiens means "wise man" in Latin. ... Humans instinctively crave meat, seek it out, associate it with wealth and well-being."

Scientists have tried various different approaches. One is to come up with plant-based dishes that have the taste and texture of meat. Burger King's Impossible Whopper is an example.

Another answer is meat created in a laboratory. This is done by growing animal cells in a large tank with nutrients and amino acidsOrganic compounds which form the basic constituents of proteins. until they form a large lump of tissue. This is then seasoned and processed in a similar way to ordinary meat, ending up as, say, a nugget or a meatball.

Then there is a combination of the two: laboratory-grown animal fat mixed into plant-based food. This supplies the flavour and texture that purely vegetarian products generally lack.

But one approach is more ambitious than all the others. The aim is not just to reproduce the experience of eating beef or chicken, but to introduce people to new and tastier alternatives, including extinct creatures such as the dodo - and perhaps ones that never existed, like the unicorn.

In March, an Australian company called Vow unveiled a meatball made with the DNA of a woolly mammothIts closest living relative is the Asian elephant. The last population lived on Wrangel Island in the Arctic Ocean. - an animal that died out around 4,000 years ago.

Vow worked with Professor Ernst Wolvetang of the Australian Institute of BioengineeringAlso known as genetic engineering. to recreate the cells for mammoth myoglobin, a muscle protein which gives meat much of its flavour. They took the DNA sequence from a mammoth fossil, plus elephant DNA, and added them to stem cellsUnspecialised cells that have the ability to develop into different types of cell. from a sheep.

Growing the 20 billion cells needed for the meatball was "ridiculously easy and fast", says Professor Wolvetang.¹ "We did this in a couple of weeks."

He adds that no one has actually tasted the meatball: "We haven't seen this protein for thousands of years, so we have no idea how our immune systemThe network of cells, organs and proteins that defend the body from infection. would react when we eat it." But it is an amazing example of what could be done.

The company is planning to launch its first product, Japanese quail, later this year. It has also been looking into more than 50 other species, including peacocks, crocodiles and kangaroos.

Yes: It is boring just to eat the same things over and over again. If we can cut down our emissions from farming and discover new tastes as well, we will have the best of both worlds.

No: We need to get away from the whole idea of eating meat, which is both cruel to animals and hugely damaging to the planet. The sooner we confine ourselves to plant-based food the better.

Or... We should not just be thinking about what humans eat. To rebalance the environment we should use our scientific knowhow to produce healthier, more sustainable food for all our fellow creatures.  

DNA - Deoxyribonucleic acid is the material in an organism that carries genetic information.

Homo sapiens - The species to which all modern humans belong. Homo sapiens means "wise man" in Latin.

Amino acids - Organic compounds which form the basic constituents of proteins.

Woolly mammoth - Its closest living relative is the Asian elephant. The last population lived on Wrangel Island in the Arctic Ocean.

Bioengineering - Also known as genetic engineering.

Stem cells - Unspecialised cells that have the ability to develop into different types of cell.

Immune system - The network of cells, organs and proteins that defend the body from infection.