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- Parent Category: Biology
- Category: Botany
The kelp forests off southern California are considered to be some of the most diverse and productive ecosystems on the planet, yet a new study indicates that today's kelp beds are less extensive and lush than those in the recent past.
The kelp forest tripled in size from the peak of glaciation 20,000 years ago to about 7,500 years ago, then shrank by up to 70 percent to present day levels, according to the study by Rick Grosberg, professor in the Department of Evolution and Ecology and the Center for Population Biology at UC Davis, with Michael Graham of the Moss Landing Marine Laboratory and Brian Kinlan at UC Santa Barbara.
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- Parent Category: Biology
- Category: Zoology
It sounds like a classic horror story—eyeless, mouthless worms lurk in the dark, settling onto dead animals and sending out green "roots" to devour their bones. In fact, such worms do exist in the deep sea. They were first discovered in 2002 by researchers at the Monterey Bay Aquarium Research Institute (MBARI), who were using a robot submarine to explore Monterey Canyon. But that wasn't the end of the story. After "planting" several dead whales on the seafloor, a team of biologists recently announced that as many as 15 different species of boneworms may live in Monterey Bay alone.
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- Parent Category: Biology
- Category: Zoology
by Stuart Wolpert
Read more: Why do animals, especially males, have so many different colors?
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- Parent Category: Biology
- Category: Zoology
Researchers from the United States and Slovenia have discovered a new, giant Nephila species (golden orb weaver spider) from Africa and Madagascar and have published their findings in the Oct. 21 issue of the journal PLoS ONE. Matjaž Kuntner, chair of the Institute of Biology of the Slovenian Academy of Sciences and Arts and a Smithsonian research associate, along with Jonathan Coddington, senior scientist and curator of arachnids and myriapods in the Department of Entomology at the Smithsonian’s National Museum of Natural History, also reconstructed size evolution in the family Nephilidae to show that this new species, on average, is the largest orb weaver known. Only the females are giants with a body length of 1.5 inches (3.8 centimeters) and a leg span of 4 - 5 inches (10 - 12 centimeters); the males are tiny by comparison. More than 41,000 spider species are known to science with about 400 - 500 new species added each year. But for some well-known groups, such as the giant golden orb weavers, the last valid described species dates back to the 19th century.
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- Parent Category: Biology
- Category: Anatomy & Physiology
Activating a small fraction of neurons triggers complete memory.
By Lizzie Buchen
Just as a whiff of pumpkin pie can unleash powerful memories of holiday dinners, the stimulation of a tiny number of neurons can evoke entire memories, new research in mice suggests.
Memories are stored in neurons distributed across a host of brain regions. When something triggers a memory, that diffuse information is immediately and cohesively reactivated, but it's unclear how the circuit gets kicked into full gear. Over the past few years, a handful of studies have suggested that a small number of neurons — perhaps even single neurons — can trigger sensations. But this idea remains controversial and has never been demonstrated with memory.
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- Parent Category: Biology
- Category: Zoology
Written by Nicole Giese
Amputations trigger a molecular response that determines if a head or tail will be regrown in planaria, a flatworm commonly studied for its regenerative capabilities. Until now, no molecular connection between wounding and the decision to regenerate either a head or tail in planaria had been identified.
Whitehead Institute scientists report this finding in the September 15-28 issue of PNAS Early Edition.
Read more: Figuring out the heads or tails decision in regeneration