From far away, the top of a leaf looks like one seamless surface; however, up close, that smooth exterior is actually made up of a patchwork of cells in a variety of shapes and sizes. Interested in how these cells individually take on their own unique forms, a team sought to pinpoint the shape-controlling factors in pavement cells, which are puzzle-piece-shaped epithelial cells found on the leaves of flowering plants.
As one of the most widely consumed and commercially important beverages on the planet, one would expect the experts to know everything there is to know about lager beer. But it was just a few years ago that scientists identified the South American yeast that somehow hitched a ride to Bavaria and combined with the domesticated Old World yeast used for millennia to make ale and bread to form the hybrid that makes lager or cold stored beer.
Why zebras have black and white stripes is a question that has intrigued scientists and spectators for centuries. A research team in California has examined this riddle systematically and have found that biting flies, including horseflies and tsetse flies, are the evolutionary driver for zebra stripes.
Fossil remains show that sometime around 252 million years ago, about 90% of all species on Earth were suddenly wiped out in what was the largest of this planet’s five known mass extinctions. But pinpointing the culprit has been difficult, and controversial. Now, a team of Massachusetts Institute of Technology researchers may have found enough evidence to convict the guilty parties, but you’ll need a microscope to see the killers.
Paleontologists studying fossilized feathers have proposed that the shapes of certain microscopic structures inside the feathers can tell us the color of ancient birds. But new research from North Carolina State Univ. demonstrates that it is not yet possible to tell if these structures, thought to be melanosomes, are what they seem, or if they are merely the remnants of ancient bacteria.
For four decades, polychlorinated biphenyls (PCBs) and heavy metals from nearby manufacturing plants flowed into New Bedford Harbor, creating one of the EPA’s largest Superfund cleanup sites. It’s also the site of an evolutionary puzzle: small Atlantic killifish are not only tolerating the toxic conditions in the harbor, they seem to be thriving there. In a new paper, researchers may have an explanation for their genetic resistance to PCBs.
The largest mass extinction in the history of animal life occurred some 252 million years ago, wiping out more than 96% of marine species and 70% of life on land. Multiple theories have aimed to explain the cause of what’s now known as the end-Permian extinction. But pinpointing the cause of the extinction requires better measurements of how long the extinction period lasted.
When people see a skunk, the reaction usually is “Eww,” but when they see a group of meerkats peering around, they often think “Aww.” Why some animals use noxious scents while others live in social groups to defend themselves against predators is the question that biologists in California have sought to answer through a comprehensive analysis of predator-prey interactions among carnivorous mammals and birds of prey.
A substantial fraction of the Neanderthal genome persists in modern human populations. A new approach applied to analyzing whole-genome sequencing data from 665 people from Europe and East Asia shows that more than 20% of the Neanderthal genome survives in the DNA of this contemporary group, whose genetic information is part of the 1,000 Genomes Project.
Insects may thrive in the warmer average temperatures predicted by climate models but are threatened by greater temperature variation also anticipated in many areas around the globe, a Yale Univ.-led study predicts. Scientists have tested the impact of temperature on 38 species of insects. The team coupled that data with historic climate data and climate projections for 2050 to 2059 in order to assess effects of temperature variability.
An international team of scientists have examined the earliest communities of large multicellular organisms in the fossil record to help answer this question of why life forms began to get larger about 580 million years ago. The research reveals that an increase in size provided access to nutrient-carrying ocean flow, giving an advantage to multicellular eukaryotes that existed prior to the Cambrian explosion of animal life.
"Where do new genes come from?" is a long-standing question in genetics and evolutionary biology. A new study from researchers at the Univ. of California, Davis, published in Science Express, shows that new genes are created from non-coding DNA more rapidly than expected.
A closer look at microbes reveals there is big business going on in their very small world, and sometimes we are part of the transaction. In a published report, an international team of researchers argue that microbes, like many animals, can evolve into savvy traders, selling high and buying low.
One of the most hotly debated issues in current human origins research focuses on how the 4.4-million-year-old African species Ardipithecus ramidus is related to the human lineage. “Ardi” was an unusual primate. Though it possessed a tiny brain and a grasping big toe used for clambering in the trees, it had small, humanlike canine teeth and an upper pelvis modified for bipedal walking on the ground.
An international research team has produced a high-quality genome sequence of a Neanderthal woman from a toe bone found in 2010 by Russian archaeologists. The genome will allow detailed insights into the relationships and population history of the Neanderthals and other extinct hominin groups.
Interplay between genes and the environment has been pondered at least since the mid-1800s. But until the arrival of modern genomic sequencing tools, it was hard to measure the extent that the environment had on a species’ genetic makeup. Now, researchers studying fruit flies that live on opposite slopes of a unique natural environment known as “Evolution Canyon” show the driving force in the gene pool is largely the environment.
Rain as acidic as undiluted lemon juice may have played a part in killing off plants and organisms around the world during the most severe mass extinction in Earth’s history. About 252 million years ago, the end of the Permian period brought about a worldwide collapse known as the Great Dying, during which a vast majority of species went extinct. The cause of such a massive extinction is a matter of scientific debate.
Scripps Institution of Oceanography researchers are unraveling the mechanisms behind a little-known marine worm that produces a dazzling bioluminescent display in the form of puffs of blue light released into seawater. This effect, produced by mucus, hasn’t been studied in more than 50 years. But two recent studies have helped reignite the quest to decode the inner workings of the worm’s bioluminescence.
Earth’s oldest sedimentary rocks are not only rare, but also almost always altered by hydrothermal and tectonic activity. The Pilbara district in Australia is a rare exception. A new study has revealed the well-preserved remnants of a complex ecosystem in a nearly 3.5 billion-year-old sedimentary rock sequence.
Scientists have puzzled for centuries over how and why multicellular organisms evolved the almost universal trait of using single cells, such as eggs and sperm, to reproduce. Now, researchers have set a big piece of that puzzle into place by applying experimental evolution to transform a single-celled algae into a multicellular one that reproduces by dispersing single cells.
A British scientist says he may have solved the mystery of the Abominable Snowman, the elusive ape-like creature of the Himalayas. DNA analysis conducted by Oxford Univ. genetics professor Bryan Sykes suggests the creature, also known as the Yeti, is the descendant of an ancient polar bear.
The discovery of a 1.8-million-year-old skull of a human ancestor buried under a medieval Georgian village provides a vivid picture of early evolution and indicates our family tree may have fewer branches than some believe, scientists say. The fossil is the most complete pre-human skull uncovered.
Enhanced growth of Earth's leafy greens during the 20th century has significantly slowed the planet's transition to being red-hot, according to the first study to specify the extent to which plants have prevented climate change since pre-industrial times. Researchers based at Princeton Univ. found that land ecosystems have kept the planet cooler by absorbing billions of tons of carbon, especially during the past 60 years.
Darwin referred to the origin of species as "that mystery of mysteries," and even today, more than 150 years later, evolutionary biologists cannot fully explain how new animals and plants arise. For decades, nearly all research in the field has been based on the assumption that the main cause of the emergence of new species, a process called speciation, is the formation of barriers to reproduction between populations. Until now.
Steven Benner of Westheimer Institute for Science and Technology will tell geochemists gathering Thursday at the annual Goldschmidt conference that an oxidized mineral form of the element molybdenum, which may have been crucial to the origin of life, could only have been available on the surface of Mars and not on Earth.