A small population?

Does "it" refer to "a small population"?

Context:

With such long stretches of DNA, Hung and his team could assess the
extent to which the sequences of DNA code in the genes in the three
specimens varied from bird to bird. With this map of genetic variation
in hand, the scientists could then estimate how big the population of
passenger pigeons once was — typically, a small population will have
less genetic variation than a larger one because it derives from a
smaller pool of ancestors who bred successfully. Through this
technique of looking at many genes on a single genome for variations,
a smattering of birds from across the breeding range can reveal the
approximate number of their peers.