Synthetic biology has made such strides in recent years that the notion of reviving extinct species is no longer crazy talk. Researchers gathered recently in Washington, D.C. to discuss the prospects of bringing back a whole menagerie of fascinating creatures, including the passenger pigeon, once the most numerous bird in North America.

At least one scientist is busy devising a strategy to teach that genetic replica how to live like its flocking, migrating natural ancestors did. But other scientists arent convinced you could ever call this bird a true passenger pigeon.

Everything we know about species and individuals tells us that were a lot more than our genes, said David Blockstein of the National Council for Science and the Environment.

For one thing, an animals genes are influenced by its environment though chemical changes to DNA that affect how genes switch on and off. Those epigenetic changes may be a crucial part of what gives a species its unique characteristics, but the epigenetic profile of a bird created in a lab would never be the same as that of a bird raised in a flock by its natural parents, Blockstein says.

Conservation biologist David Ehrenfeld of Rutgers University is skeptical too.Lets say we could create a passenger pigeon with the same DNA and the same epigenetic marks, he said. That doesnt make it a passenger pigeon.

Ehrenfeld and others say passenger pigeons were perhaps the most social birds that have ever existed, living in flocks of hundreds of thousands. They needed enormous populations to nest properly and repel predators, Ehrenfeld said. Their behavior, as much as their DNA, defined the species.

This concept isnt lost on the people behind the plan to revive the passenger pigeon.

In my opinion you have to recreate the social structure, said Ben Novak, a young scientist who is heading the project, supported by a group called Revive & Restore. Novak outlined his plan at the meeting in Washington, and he described it in more detail in an interview with Wired last week.

The first passenger pigeons would be raised in captivity, with surrogate parents of a related species. Novak plans to cosmetically alter the surrogates with dyes to give them the reddish bellies and grey wings of passenger pigeons. These indoor aviaries would be adorned with tree branches and decorated to be as forest-like as possible. Ideally, birds would even have to forage for their own food, Novak says. After a few years of captive breeding to build up the population, the birds would gradually be transferred to outdoor aviaries.

As the captive flock continues to grow, Novak plans to train homing pigeons as guides to teach the passenger pigeons to migrate along the flyways of their extinct ancestors. The idea would be to dye the homing pigeons so they look like passenger pigeons, allow young passenger pigeons to imprint on them, and then release them all and hope that the passenger pigeons follow their homing-pigeon guides.

Read the original post:
Say We Really Do Bring the Passenger Pigeon Back From Extinction — Then What?

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