Columbia River Chinook salmon have lost as much as two-thirds of their genetic diversity, Washington State University researchers have found.
Writing in the journal PLOS One, the researchers say their analysis “provides the first direct measure of reduced genetic diversity for Chinook salmon from the ancient to the contemporary period.”
“The big question is: Is it the dams or was it this huge fishing pressure when Europeans arrived?” said Bobbi Johnson, who did the study as part of her WSU doctorate in biological sciences. “That diversity could have been gone before they put the dams in.”
As weird animals go, the mangrove killifish is in a class of its own.
It flourishes in both freshwater and water with twice as much salt as the ocean. It can live up to two months on land, breathing through its skin, before returning to the water with a series of spectacular 180-degree flips.
And it is one of only two vertebrates — the other is a close relative — that fertilizes itself.
This last part intrigues scientists like Luana Lins, a postdoctoral researcher in the Washington State University School of Biological Sciences.
Scientists have long assumed that the sugars that nourish trees are pushed by water pressure from the leaves where they are created to the stems and roots where they are needed. But how do taller trees accomplish that task, given the longer distances the nutrients must travel and the greater force that seems needed to transport them?
A nine-member team of scientists, including Michael Knoblauch, a plant cell biologist from Washington State University, discovered an answer with a recent study whose findings could also help end a longstanding debate over the dynamics involved in sugar transport in trees. The study, whose results are detailed in the Dec. 4 issue of the journal Nature Plants, determined that the hydraulic resistance to moving sugar-rich sap downward from the leaves does not increase with the height of the tree as much as would be expected, because of physical features in the transport system.
First, the good news. Washington State University researchers have found that a rat exposed to a popular herbicide while in the womb developed no diseases and showed no apparent health effects aside from lower weight.
Now, the weird news. The grand-offspring of that rat did have more disease, as did a great-grand offspring third generation.
“The third generation had multiple diseases and much more frequently than the third generation of unexposed rats,” said Michael Skinner, a Washington State University professor of biological sciences. At work, says Skinner, are epigenetic inheritance changes that turn genes on and off, often because of environmental influences.
The National Weather Service predicts highs in the mid-90s for the rest of the week, but a team of climate experts from across the country predicts the region will experience a higher frequency of extremely hot days in the decades to come.
According to an interactive map of temperatures based off data from collaborative research team Climate Impact Lab and published by The Seattle Times, the entire state of Washington will experience an increasing number of days with temperatures over 95 degrees Fahrenheit in the coming years – whether countries take action against climate change in the future or not.
So why does it matter? Besides the obvious potential dangers and everyday annoyances a sweltering hot day poses, Asaph Cousins, associate professor of plant biology for Washington State University, said such temperature changes generally have a dramatic impact on plant life.