EAST LANSING, Mich. – To paraphrase the Rolling Stones: We can’t always get everything we want in life, but we get what we need. Michigan State University researchers believe this is a powerful principle in evolution as well. Trade-offs, which are evolutionary compromises, drive the diversity of life, said Chris Adami, MSU professor of microbiology and molecular genetics. (more…)
Why did life forms first begin to get larger and what advantage did this increase in size provide? UCLA biologists working with an international team of scientists examined the earliest communities of large multicellular organisms in the fossil record to help answer this question. (more…)
At the end of the last Ice Age, as the world began to warm, a swath of the North Pacific Ocean came to life. During a brief pulse of biological productivity 14,000 years ago, this stretch of the sea teemed with phytoplankton, amoeba-like foraminifera and other tiny creatures, who thrived in large numbers until the productivity ended—as mysteriously as it began—just a few hundred years later.
Researchers have hypothesized that iron sparked this surge of ocean life, but a new study led by Woods Hole Oceanographic Institution (WHOI) scientists and colleagues at the University of Bristol (UK), the University of Bergen (Norway), Williams College and the Lamont Doherty Earth Observatory of Columbia University suggests iron may not have played an important role after all, at least in some settings. The study, published in the journal Nature Geoscience, determines that a different mechanism—a transient “perfect storm” of nutrients and light—spurred life in the post-Ice Age Pacific. Its findings resolve conflicting ideas about the relationship between iron and biological productivity during this time period in the North Pacific—with potential implications for geo-engineering efforts to curb climate change by seeding the ocean with iron. (more…)
Even as the dinosaurs were becoming extinct 66 million years ago, the ancient ancestor of spiny-rayed fishes flourished, eventually giving rise to tens of thousands of species that can now be found in home aquariums or on dinner plates. Using modern genetic tools and information from the fossil record, a team led by researchers at Yale University, University of Oxford, and University of California-Davis have constructed a detailed evolutionary history of the 18,000 species of spiny-rayed fishes existing today, a diverse group that includes basses, pufferfishes, and cichlids, and that comprises a large portion of the vertebrate tree of life.
The findings published the week of July 15 in the Proceedings of the National Academy of Sciences show surprisingly close evolutionary relationships between lineages of fish species such as tunas and seahorses, and suggest some fish lineages — like cichlids, the tiny gobies, and little-studied snailfishes — are experiencing high rates of new species origination. (more…)
Although scientists have known since the middle of the 19th century that the tropics are teeming with species while the poles harbor relatively few, the origin of the most dramatic and pervasive biodiversity on Earth has never been clear.
New research sheds light on how that pattern came about. Furthermore, it confirms that the tropics have been and continue to be the Earth’s engine of biodiversity. (more…)
The turtle has been in no rush to give up the secret of its shell — but after two centuries of close study, scientists are filling in the story of a structure unique in the history of life.
New research led by Tyler Lyson of Yale University and the Smithsonian Institution pushes back the origins of the turtle shell by about 40 million years, linking it to Eunotosaurus, a 260-million-year-old fossil reptile from South Africa. The work strengthens the fossil record and bolsters an existing theory about shell development while providing new details about its precise evolutionary pathway.(more…)
Fossil-hunting expeditions to Tanzania, Zambia and Antarctica provide new insights
Predecessors to dinosaurs missed the race to fill habitats emptied when nine out of 10 species disappeared during Earth’s largest mass extinction 252 million years ago.
Or did they?
That thinking was based on fossil records from sites in South Africa and southwest Russia.
It turns out, however, that scientists may have been looking in the wrong places. (more…)
University of Colorado Boulder astronomers targeting one of the brightest quasars glowing in the universe some 11 billion years ago say “sideline quasars” likely teamed up with it to heat abundant helium gas billions of years ago, preventing small galaxy formation.
CU-Boulder Professor Michael Shull and Research Associate David Syphers used the Hubble Space Telescope to look at the quasar — the brilliant core of an active galaxy that acted as a “lighthouse” for the observations — to better understand the conditions of the early universe. The scientists studied gaseous material between the telescope and the quasar with a $70 million ultraviolet spectrograph on Hubble designed by a team from CU-Boulder’s Center for Astrophysics and Space Astronomy. (more…)