SORU: aşağıdaki parçaya göre cevaplayınız
According to the passage, scientists were surprised that ----.
Despite bacteria's presence in all parts of the planet,
their diversity in the world's soils is poorly
understood. To better understand what makes the
organisms thrive, Duke University researchers
trekked far and wide to collect a few centimetres of
dirt as samples from 98 locations across North and
South America, then analyzed each sample for
genetic variation. To their surprise, the strongest
predictor of high diversity was neutral pH. The acidic
soil of the Peruvian Amazon, for example, harboured
far fewer bacterial species than did the neutral dirt of
the arid American Southwest. “There are a lot of
variables that didn't turn out to be very important,”
says the researcher Robert Jackson, who adds that a
more complete search for different habitats might
turn up other stimulators of diversity, such as carbon
abundance.