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.

Scientists have tried various different approaches. One is to come up with plant-based dishes that have the taste and texture of meat.

Another answer is meat created in a laboratory. Then there is a combination of the two: laboratory-grown animal fat mixed into plant-based food.

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 system 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.