Apart from cloning. From ScienceDaily:
In the new study, Valente and colleagues developed a method to estimate how long it would take for islands to regain the number of species lost due to humans. They realized that New Zealand birds would be an ideal system to apply and demonstrate this new method.
“The anthropogenic wave of extinction in New Zealand is very well documented, due to decades of paleontological and archaeological research,” Valente says. “Also, previous studies have produced dozens of DNA sequences for extinct New Zealand birds, which were essential to build datasets needed to apply our method.”
Using computers to simulate a range of human-induced extinction scenarios, the researchers found that it would take approximately 50 million years to recover the number of species lost since human’s first arrived in New Zealand. If all species currently under threat are allowed to go extinct, they report, it would require about 10 million years of evolutionary time to return to the species numbers of today. Paper. (open access) – Luis Valente, Rampal S. Etienne, Juan C. Garcia-R. Deep Macroevolutionary Impact of Humans on New Zealand’s Unique Avifauna. Current Biology, 2019; 29 (15): 2563 DOI: 10.1016/j.cub.2019.06.058 More.
There would doubtless be species but they might not be at all like the lost ones. They might not be birds.
An extinct life form could probably never be brought back, unless it can be cloned. A given fifty million years in the future will be quite different from fifty million years in the past. There is no reason to think the same species would arise during that period at all.
Apart from cloning, to get the exact same birds, we’d have to rent the multiverse (if it existed). And then we would have an infinite number of planets with islands like New Zealand, including these birds. Never mind one…
But if games with numbers do help to raise awareness so one enters an objection mainly as a matter of form.
See also: Why didn’t saber-tooth tigers survive? Why coyotes instead?
and
Humans off the hook for ancient African mammal extinction?
and
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