While most scientists agree that the climate is changing, the extent to which species will be able to evolve to keep up with these changes is unknown.
According to the article, the only way that scientists can detect the results of those sorts of calamitous changes and test evolutionary predictions about what sorts of changes might occur over time is to sample seed banks in a repeated fashion. Then they must compare the attributes of the gene pools that are sampled at different times to a baseline.
"One way that we can obtain this baseline is by collecting seeds at a given point in time and archiving them under ideal environmental conditions, so that they all stay alive, and so that 10, 20, and 30 years down the road, we can compare them to seeds that we collect in the future to see how the gene pool has changed," explained Mazer.
This approach will allow a number of things that a one-time, seed-sampling event doesn't. Scientists can evaluate the result of the effects of climate change, land use change, and other kinds of environmental changes such as the spread of disease on the gene pool.
"Currently seed banks don't allow this for a couple of reasons," said Mazer. "First, they focus on species that have been under cultivation for a long period. Species that have been under cultivation have relatively low levels of genetic variation because we have been selecting them only for the attributes that we want. Wild species, by contrast, contain a high degree of genetic variation in almost any trait that we might examine."
Agricultural species are often selected to have a predictable flowering time, a predictable seed size and a predictable degree of tolerance for drought, salt, or heavy metals. By contrast, wild species retain a much greater degree of genetic diversity in all of these traits.
Mazer explained that scientists don't
|Contact: Gail Gallessich|
University of California - Santa Barbara