It’s also not a question with a happy answer. These are all examples of animals that are now extinct, and it looks like we’ll soon be adding another species to the list. 

This week the last male northern white rhino, named Sudan, passed away in Kenya. This leaves just two more northern white rhinos in existence, and both are females who seem unable to reproduce. 

So does this really mean it is the end for the northern white rhino?

Some scientists hope not – and they have a plan to save the rhino. Researchers in Kenya were able to collect and store semen from Sudan before his death, and are also collecting eggs from the female white rhinos. They are then hoping that they can use in vitro fertilisation (IVF) technology to create northern white rhino embryos in a laboratory, then transfer them into surrogate female Southern white rhinos (a related species) to grow. Hopefully, with the help of these artificial reproduction methods, scientists could bring the northern white rhino back in the future.

It’s an ambitious plan. But nowhere near as ambitious as the plans of other scientists, like a team working at Harvard University, who would like to try and revive another extinct species - the Woolly mammoth.

At least in the case of the northern white rhino researchers have some semen and eggs to work with. In the case of the Woolly mammoth all they have are some DNA samples that have been frozen for thousands of years. But scientists think it might just be enough, when combined with new gene editing technology.

The plan is to take pieces of mammoth DNA, and splice them into elephant DNA – then create an embryo in the lab and grow it in an artificial womb.

The result would not be a true mammoth, it would really be a hybrid between a mammoth and an elephant. Picture Dumbo but with long shaggy hair, tusks, and the ability to live happily in the arctic. Scientists have already created some of these elephant-mammoth hybrid cells, but are still a long way from being able to turn those cells into a whole animal.

Other researchers are exploring the possibilities of “de-extinction” of other species, including the Tasmanian tiger, using similar methods. But not all scientists are on board with the idea. Some conservationists believe that re-introducing these species would cause damage to our modern environments, which have undergone significant changes since these animals went extinct. Then there is the financial cost. These cutting-edge technologies cost millions of dollars – money that some argue could be better spent on conservation programs to help prevent more endangered species from becoming extinct in the first place.

I doubt that I’m going to see a mammoth or a Tasmanian tiger wandering around in my lifetime. But it’s exciting to think that we could use modern technologies to help save endangered species from extinction, and it would be really nice if we didn’t need to add to that list of extinct animals after all.