Scientists Aim to Give the Dodo a 2nd Chance

A Texas-based biosciences startup's plan to bring back a wolf-like animal that's thought to have gone extinct in 1936 seems quaint when stacked against its latest plan: to de-extinct a bird that last walked the earth in the late 1600s. Colossal Biosciences on Tuesday said it will endeavor to bring back the dodo bird, a desired feat the company indicates is more doable thanks to $150 million in new funding it has secured, reports Gizmodo. That means Colossal Biosciences has its sights set on resurrecting three creatures: the dodo, the aforementioned thylacine, and the woolly mammoth. The most interesting bits about the science around this quest:

• Initial steps: The bird's genome has been sequenced using centuries-old remains and the DNA was next compared to the bird's closest known relatives, the Nicobar pigeon and the Rodrigues solitaire. The latter, like the dodo, is an extinct flightless bird that lived near the dodo's home island of Mauritius. The goal: zero in on which mutations in the genome "make a dodo a dodo," lead paleogeneticist Beth Shapiro tells CNN.
• Semantics: Using the word "de-extinction" to describe the effort isn't quite right, notes Gizmodo. The best thing Colossal can land on is "science’s best analogue for an extinct creature, not the creature itself as it existed in the past." That's because a living creature’s genetics will need to factor in to the process, meaning "any 21st-century mammoth will have at least some modern elephant DNA imbued in it."

• One tough part: The general thinking on how to arrive at that proxy involves "editing the genome of a closely related living species to replicate the target species’ genome," Scientific American explains. "The edited genome would then be implanted into an egg cell of that related species to develop." But "there is no access to a bird egg cell at the same developmental time as there is for a mammal," Shapiro says. The route Colossal is plotting involves extracting avian primordial germ cells—cells that eventually become sperm or eggs—from pigeon eggs and manipulating them so that they develop into a dodo proxy.
• One slightly easier part: If the above makes avian genetics tougher, there's one thing that makes it easier, notes Scientific American: "With mammals, scientists don’t yet know how the modified embryo of an extinct species will interact with the intrauterine environment of the host species." Shapiro says that's not the case here "because everything happens in an egg."
• Timing: Colossal CEO Ben Lamm says the company hopes to birth its first mammoth in 2028, and the dodo would likely precede it. "Given the significantly shorter timeline of gestation of 30 days versus the 22 months in elephants, I think it is highly likely we see a dodo before we see the mammoth," he tells Fast Company.

(More dodo bird stories.)