The Earth has been through a lot of changes in its 4.5 billion year history, including a shift to incorporating and retaining volatile compounds such as water, nitrogen and carbon from the atmosphere in the mantle before spewing them out again through volcanic eruptions.
This transport could not have begun much before 2.5 billion years ago, according to researchers at UC Davis and Washington University in St. Louis, published Aug. 9 in the journal Nature.
How does a fish avoid being eaten by a bigger fish? Evolution could build up defenses such as spines or armor, or favor avoidance strategies such as quick reactions, swimming away and hiding. The rules of evolution are tough, so you cannot really have both, the argument goes.
But this hypothesis has been difficult to test in practice. Now Jennifer Hodge, a postdoctoral researcher working with Professor Peter Wainwright and colleagues in the UC Davis Department of Evolution and Ecology, College of Biological Sciences, has carried out a survey of hundreds of specimens of butterflyfish, carefully measuring their physical traits and defenses compared to feeding style.
As lizards before the hurricane fly: A new study in the journal Nature gives a graphic demonstration of natural selection in action. It’s about Anole lizards living on islands in the Caribbean and how they survived – or not – two violent hurricanes in 2017.
Anolis scriptus lizards are endemic to the Turks and Caicos Islands. (Colin Donihue/Harvard University)
Thomas Schoener, professor of evolution and ecology in the UC Davis College of Biological Sciences, is a coauthor on the paper. Schoener has extensively studied these lizards and other animals on small Caribbean islands as models for evolution and natural selection.
The snipefish, an ocean-dwelling relative of the seahorse, has a very long, skinny snout ending in a tiny mouth. A recent study by UC Davis graduate student Sarah Longo shows that snipefish feed with an elastic-boosted head flick at almost unprecedented speed.
“At as little as two milliseconds, it’s among the fastest feeding events ever recorded for fish,” said Longo, now a postdoctoral researcher at Duke University.
Snipefish, seahorses and pipefish all have long, skinny snouts and use “pivot feeding” to capture food, Longo said, meaning that they pivot their head rapidly to bring their mouth up close to the prey and suck it in.
Photosynthesis is one of the most crucial life processes on earth. It’s how plants get their food, using energy from sunlight to convert water and carbon dioxide from the air into sugars. It’s long been thought that more than 30 percent of the energy produced during photosynthesis is wasted in a process called photorespiration.
A new study led by researchers at the University of California, Davis, suggests that photorespiration wastes little energy and instead enhances nitrate assimilation, the process that converts nitrate absorbed from the soil into protein.
Study shows plants may not lose energy during photosynthesis. (Getty Images)
“Black smokers,” or high-temperature hydrothermal vents at the bottom of the ocean, have generated a lot of scientific interest since they were discovered forty years ago. By belching hot, mineral-laden water, these vents support communities of microbes and animals far from sunlight.
Octopuses incubate their eggs near the slightly warmer streams of water from cool hydrothermal vents deep in the ocean. Credit: Woods Hole Oceanographic Institution
But not all ocean vents are hot. Cool hydrothermal systems, or cool vents, are much harder to spot because the fluids they release are clear and only a bit warmer than surrounding water. Yet they could play a major role in releasing minerals into the deep ocean.
The Mars Curiosity rover team announced today (June 7) finding organic matter – carbon-based compounds – in three billion year old mudstone sediments from Gale Crater. They also found seasonal changes in the amount of methane in the local atmosphere.
Dawn Sumner is a member of the Mars Curiosity team.
Dawn Sumner, professor of earth and planetary sciences at UC Davis, is a member of the Mars Curiosity team and coauthor on the first paper. She helps with sample selection and mission planning and was instrumental in promoting Gale Crater as a landing site for Curiosity.
Kilauea volcano on the island of Hawaii continues to erupt, creating spectacular footage of lava shooting out of vents and eating cars. While the lava flows are slow moving, and so far no one has been hurt, U.S. Geological Survey scientists were today (May 10) warning that the volcano might erupt explosively, sending large rocks flying through the air.
This 8-10 ton boulder fell on a landing strip about a kilometer from Halema‘uma‘u crater during the eruption of May, 1924 (USGS photo collection).