And the way it was done was simply to say, 'We know how many species or birds there are alive today.' There are 10,000, and the initial estimate for the diversity of all of life were 100 million.
A única forma de o fazer é dizer simplesmente: "Sabemos quantas espécies de aves vivas existem hoje". São 10 000. A estimativa inicial para a diversidade de toda a vida era de 100 milhões.