5 extinct species that could make a comeback

In a quiet lab somewhere, the ghost of the dodo may be stirring.

It sounds like science fiction, but across the world, scientists are working to revive animals that vanished long ago. The field of de-extinction is gaining momentum. From woolly mammoths to mouth-birthing frogs, here are five species that could return — at least in part.

Woolly Mammoth

Towering beasts of the Ice Age, woolly mammoths roamed the frozen plains for thousands of years. Their closest living relative, the Asian elephant, may soon help bring them back. Using preserved mammoth DNA, scientists are trying to engineer cold-resistant elephants that resemble their extinct cousins. U.S.-based company Colossal Biosciences hopes to welcome a "mammoth" calf by 2028.

Dodo

This flightless bird disappeared from Mauritius in the 1600s, wiped out by invasive species and human activity. In 2022, scientists sequenced the dodo's genome from a museum specimen. Now, efforts are underway to modify pigeon DNA and hatch a modern version of the dodo. The challenges are steep, but not impossible.

Thylacine (Tasmanian Tiger)

Last seen in 1936, this striped marsupial once roamed across Australia. Researchers in Melbourne have pieced together its genome and are working to edit the DNA of a related marsupial. If successful, thylacines could one day return to Tasmania's wild.

Passenger Pigeon

Once numbering in the billions, these birds vanished by 1914. Revive & Restore, a US biotech group plans to reintroduce their traits into living pigeons. Trials could begin as soon as this year.

Aurochs

Ancestors of modern cattle, the aurochs, died out in the 1600s. Unlike others on this list, scientists are not recreating them with gene editing. Instead, they are "back-breeding" modern cows to resemble their wild forebears. The results are already occurring in Europe.