Showing 20 articles starting at article 261
< Previous 20 articles Next 20 articles >
Categories: Biology: Botany, Paleontology: Early Mammals and Birds
Published Woolly mammoth movements tied to earliest Alaska hunting camps
(via sciencedaily.com) Original source Researchers have linked the travels of a 14,000-year-old woolly mammoth with the oldest known human settlements in Alaska, providing clues about the relationship between the iconic species and some of the earliest people to travel across the Bering Land Bridge. Isotopic data, along with DNA from other mammoths at the site and archaeological evidence, indicates that early Alaskans likely structured their settlements to overlap with areas where mammoths congregated. Those findings, highlighted in the new issue of the journal Science Advances, provide evidence that mammoths and early hunter-gatherers shared habitat in the region. The long-term predictable presence of woolly mammoths would have attracted humans to the area.
Published Silkmoths: Different olfactory worlds of females and males
(via sciencedaily.com) Original source Female moths primarily use their sense of smell to find the best host plants on which to lay their eggs, with the deterrent effect of caterpillar feces playing an important role, according to new research.
Published Climate change threatens global forest carbon sequestration, study finds
(via sciencedaily.com) Original source Climate change is causing Western U.S. forests to be less effective carbon sinks, even as it boosts the productivity of forests in the Eastern U.S., according to new research.
Published Pacific kelp forests are far older that we thought
(via sciencedaily.com) Original source Fossils of kelp along the Pacific Coast are rare. Until now, the oldest fossil dated from 14 million years ago, leading to the view that today's denizens of the kelp forest -- marine mammals, urchins, sea birds -- coevolved with kelp. A recent amateur discovery pushes back the origin of kelp to 32 million years ago, long before these creatures appeared. A new analysis suggests the first kelp grazers were extinct, hippo-like animals called desmostylians.
Published New rice lines for Africa offer virus protection
(via sciencedaily.com) Original source The so-called Rice Yellow Mottle Virus (for short: RYMV) is responsible for high crop losses in Africa, particularly among small-scale farmers. A research team has now produced rice lines that are resistant to the disease by means of genome editing. The rice varieties are a preliminary step toward being able to generate resistant locally adapted elite varieties for small-scale food producers in Africa.
Published Human activity facilitates invasive plants' colonization in Mediterranean ecosystems
(via sciencedaily.com) Original source Some invasive plants can form persistent banks of seeds that remain under the soil for years, and this makes their eradication practically impossible. Over time, this invisible population of large quantities of living, buried plants -- in seed form -- will reoccupy ecosystems and displace the typical flora of the natural environment.
Published Oldest known fossilized skin is 21 million years older than previous examples
(via sciencedaily.com) Original source Researchers have identified a 3D fragment of fossilized skin that is at least 21 million years than previously described skin fossils. The skin, which belonged to an early species of Paleozoic reptile, has a pebbled surface and most closely resembles crocodile skin. It's the oldest example of preserved epidermis, the outermost layer of skin in terrestrial reptiles, birds, and mammals, which was an important evolutionary adaptation in the transition to life on land.
Published Toxic algae blooms: Study assesses potential health hazards to humans
(via sciencedaily.com) Original source Water samples from 20 sites were tested using a panel of immortalized human cell lines corresponding to the liver, kidney and brain to measure cytotoxicity. Results show that each control toxin induced a consistent pattern of cytotoxicity in the panel of human cell lines assayed. Known toxins were seen only during blooms. Because cell toxicity was seen in the absence of blooms, it suggests that there might be either emergent toxins or a combination of toxins present at those times. Findings suggest that other toxins with the potential to be harmful to human health may be present in the lagoon.
Published New research sheds light on an old fossil solving an evolutionary mystery
(via sciencedaily.com) Original source Picrodontids -- an extinct family of placental mammals that lived several million years after the extinction of the dinosaurs -- are not primates as previously believed.
Published Iron influences plant immunity and may promote resiliency against climate change
(via sciencedaily.com) Original source Researchers discovered that plants manage iron deficiency without helping 'bad' bacteria thrive by eliminating the molecular signal for iron deficiency, and that the iron deficiency signaling pathway and the plant immune system are deeply intertwined. Their findings provide a new target for boosting plant resilience in the face of climate change, and offer new insight into plant and animal microbiomes.
Published Scientists name the most common tropical tree species
(via sciencedaily.com) Original source Researchers have found almost identical patterns of tree diversity across the world's tropical forests. The study of over one million trees across 1,568 locations found that just 2.2% of tree species make up 50% of the total number of trees in tropical forests across Africa, the Amazon, and Southeast Asia. Each continent consists of the same proportion of a few common species and many rare species.
Published Plant warfare: The crucial function of Nrc proteins in tomato defense mechanisms
(via sciencedaily.com) Original source New research delves into the intricate defense mechanisms of tomatoes against the notorious bacterial pathogen, Pseudomonas syringae pv. tomato (Pst). It's a classic tale of nature's arms race: as pathogens evolve to outsmart plant defenses, plants counter with more sophisticated immune responses.
Published Scientists engineer plant microbiome to protect crops against disease
(via sciencedaily.com) Original source Scientists have engineered the microbiome of plants for the first time, boosting the prevalence of 'good' bacteria that protect the plant from disease. The findings could substantially reduce the need for environmentally destructive pesticides.
Published Why are bees making less honey? Study reveals clues in five decades of data
(via sciencedaily.com) Original source Honey yields in the U.S. have been declining since the 1990s, with honey producers and scientists unsure why, but a new study has uncovered clues in the mystery of the missing honey.
Published Researchers improve seed nitrogen content by reducing plant chlorophyll levels
(via sciencedaily.com) Original source Chlorophyll plays a pivotal role in photosynthesis, which is why plants have evolved to have high chlorophyll levels in their leaves. However, making this pigment is expensive because plants invest a significant portion of the available nitrogen in both chlorophyll and the special proteins that bind it. As a result, nitrogen is unavailable for other processes. In a new study, researchers reduced the chlorophyll levels in leaves to see if the plant would invest the nitrogen saved into other process that might improve nutritional quality.
Published New reptile on the block: A new iguana species discovered in China
(via sciencedaily.com) Original source Researchers have identified a new iguana species, Wang's garden lizard (Calotes wangi), in southern China and northern Vietnam. This species, part of the Calotes versicolor complex, was discovered through extensive surveys conducted from 2009 to 2022. Measuring less than 9 cm with an orange tongue, it inhabits subtropical and tropical forests, thriving in various landscapes including urban areas.
Published Electronic 'soil' enhances crop growth
(via sciencedaily.com) Original source Barley seedlings grow on average 50% more when their root system is stimulated electrically through a new cultivation substrate. Researchers have now developed an electrically conductive 'soil' for soil-less cultivation, known as hydroponics.
Published Insects already had a variety of defense strategies in the Cretaceous
(via sciencedaily.com) Original source Analyses of amber show that insect larvae were already using a wide variety of tactics to protect themselves from predators 100 million years ago.
Published Discovery: Plants use 'Trojan horse' to fight mold invasions
(via sciencedaily.com) Original source Scientists have discovered that plants send tiny, innocuous-seeming lipid 'bubbles' filled with RNA across enemy lines, into the cells of the aggressive mold. Once inside, different types of RNA come out to suppress the infectious cells that sucked them in.
Published Tree plantations can get better with age -- but original habitats are best
(via sciencedaily.com) Original source Older tree plantations can be more attractive to animals who are looking for a new home than younger plantations, according to a new study. In the tropics, older plantations also welcome a greater variety of different plants and animals -- though sadly, Christmas tree plantations do not become more biodiverse over time.