04 Jul
Species Have Come and Gone
View a video interview with researcher John Alroy of the National Center for Ecological Analysis and Synthesis. Diversity among the ancestors of such marine creatures as clams, sand dollars and lobsters showed only a modest rise beginning 144 million years ago with no clear trend afterwards, as per an international team of researchers. This contradicts prior work showing dramatic increases beginning 248 million years ago and may shed light on future diversity……..
Commercial flower and plant growers know all too well that invasive, ubiquitous weeds cause trouble by lowering the value and deterring healthy growth of potted ornamental plants. To control weeds, a number of commercial nursery owners resort to the expensive practice of paying workers to hand-weed containers. Some growers use herbicides, but efficacy of herbicides is questionable on the wide range of plant species produced in nurseries, and a number of herbicides are not registered for use in greenhouses……..
A farm irrigation canal would seem a healthier place for toads than a ditch by a supermarket parking lot. But University of Florida researchers have found the opposite is true. In a study with wide implications for a longstanding debate over whether agricultural chemicals pose a threat to amphibians, UF zoologists have observed that toads in suburban areas are less likely to suffer from reproductive system abnormalities than toads near farms where some had both testes and ovaries……..
To kick off the Los Angeles Zoo’s summer activities, the Zoo is cutting admission prices for the July 4 weekend. From Friday, July 4, to Sunday, July 6, 2008 everyone can slash $4 off the price of Zoo admission! In addition to the discount, guests will also be able to buy a delicious BBQ meal, get free samples of Nestle Juicy Juice and enjoy the music of a local surf band. Take advantage of this special holiday deal to visit all of the Zoo’s adorable babies!…….
What do humans and single-celled choanoflagellates have in common? More than you’d think. New research into the choanoflagellate genome shows these ancient organisms have similar levels of proteins that cells in more complex organisms, including humans, use to communicate with each other. As per a paper published last week in the Proceedings of the National Academies of Science, these findings help confirm choanoflagellates’ role as an evolutionary link between single-celled and multi-celled organisms. They also contend that these insights into the organism’s genome may mean that the proteins used to help cells communicate may have other roles as well. The scientists are from the University of California, San Francisco and the European Molecular Biology Laboratory in Heidelberg, Gera number of……..
As anyone who has suffered from jetlag knows, we have internal clocks that tell us when to sleep and wake, and we can be miserable when these are disrupted. The daily cycles of a number of organisms are well known, but what has not been clear is whether these cycles are just responses to external cues of light, dark, heat, and cold, or if there are internal clocks that are set and reset by environmental signals. In animals, circadian rhythms are known to be important for maintaining a multitude of physiological processes. They may be even more critical for plants, which grow in a number of different light and temperature environments that not only vary with latitude but also with subtle differences within just a few feet. Plants respond to changes in light and temperature, opening flowers at dawn and closing them at night or blooming in the right season. However, they also have endogenous circadian (”around the day”) rhythms with roughly 24 hour periods that are regulated by numerous genes that interact in complex pathways and cycles like exquisite 18th century clocks. These clock genes have been intensely investigated over the last 20 years, but we still do not fully understand the molecular mechanisms that make them run. Knowledge of these oscillations and the genes that regulate them could help us adjust the growth, development, and yield of crops under climatically variable conditions……..
The ecology of penguins makes these iconic swimming and diving seabirds of the Southern Hemisphere uncommonly susceptible to environmental changes. Pronounced warming in the Antarctic, as well as commercial fishing, mining, and oil and gas development at lower latitudes, has led to declines in a number of species, as per P. Dee Boersma, of the University of Washington in Seattle. In the July/August 2008 issue of BioScience, Boersma provides a first-person account based on 30 years of studying the birds. Counts of the penguin populations at the 43 remaining breeding “hotspots,” even once every five years, could provide valuable insights into the variability of the ocean ecosystem and the populations’ viability, Boersma writes. Yet counts are carried out only rarely, if at all……..
