(Press-News.org) RIVERSIDE, Calif. — A research team led by biogeochemists at the University of California, Riverside has tested a popular hypothesis in paleo-ocean chemistry, and proved it false.
The fossil record indicates that eukaryotes — single-celled and multicellular organisms with more complex cellular structures compared to prokaryotes, such as bacteria — show limited morphological and functional diversity before 800-600 million years ago. Many researchers attribute the delayed diversification and proliferation of eukaryotes, which culminated in the appearance of complex animals about 600 million years ago, to very low levels of the trace metal zinc in seawater.
As it is for humans, zinc is essential for a wide range of basic cellular processes. Zinc-binding proteins, primarily located in the cell nucleus, are involved in the regulation of gene transcription.
Eukaryotes have increasingly incorporated zinc-binding structures during the last third of their evolutionary history and still employ both early- and late-evolving zinc-binding protein structures. Zinc is, therefore, of particular importance to eukaryotic organisms. And so it is not a stretch to blame the 1-2-billion-year delay in the diversification of eukaryotes on low bioavailability of this trace metal.
But after analyzing marine black shale samples from North America, Africa, Australia, Asia and Europe, ranging in age from 2.7 billion years to 580 million years old, the researchers found that the shales reflect high seawater zinc availability and that zinc concentrations during the Proterozoic (2.5 billion to 542 million years ago) were similar to modern concentrations. Zinc, the researchers posit, was never biolimiting.
Study results appear online Dec. 23 in Nature Geoscience.
"We argue that the concentration of zinc in ancient marine black shales is directly related to the concentrations of zinc in seawater and show that zinc is abundant in these rocks throughout Earth's history," said Clint Scott, the first author of the research paper and a former UC Riverside graduate student. "We found no evidence for zinc biolimitation in seawater."
Scott, now a research geologist with the U.S. Geological Survey, explained that the connection between zinc limitation and the evolution of eukaryotes was based largely on the hypothesis that Proterozoic oceans were broadly sulfidic. Under broadly sulfidic conditions, zinc should have been scarce because it would have rapidly precipitated in the oceans, he explained.
"However, a 2011 research paper in Nature also published by our group at UCR demonstrated that Proterozoic oceans were more likely broadly ferruginous — that is, low in oxygen and iron-rich — and that sulfidic conditions were more restricted than previously thought," said Scott, who performed the research in the lab of Timothy Lyons, a professor of biogeochemistry and the principal investigator of the research project.
The research team argues that ferruginous deep oceans, combined with large hydrothermal fluxes of zinc via volcanic activity on the seafloor, maintained high levels of dissolved zinc throughout the oceans and provided a relatively stable marine reservoir of the trace metal over the past 2.7 billion years.
"The key challenge in understanding the early evolution of life is recognizing the environmental conditions under which that life first appeared and diversified," Lyons said. "We have taken a very direct approach that specifically tracks the availability of essential micronutrients, and, to our surprise, zinc supplies in ancient seawater were much higher and less variable than previously imagined.
"We can imagine for the first time," he quipped, "that zinc supplements were not on the shopping lists of our early eukaryotic ancestors, and so we better find another reason to explain the mysterious delay in their rise in the ocean."
INFORMATION:
Scott, who graduated with a doctoral degree in geological sciences from UCR in 2009, and Lyons were joined in the study by Noah J. Planavsky, a former UCR graduate student in Lyons' lab; Chris L. Dupont at the J. Craig Venter Institute, La Jolla, Calif.; Brian Kendall and Ariel D. Anbar at Arizona State University; Benjamin C. Gill at Virginia Polytechnic Institute and State University and also a former member of the Lyons lab; Leslie J. Robbins and Kurt O. Konhauser at the University of Alberta, Canada; Kathryn F. Husband and Simon W. Poulton at the University of Leeds, United Kingdom; Gail L. Arnold at the Max Planck Institute for Marine Microbiology, Germany; Boswell A. Wing at McGill University, Canada; and Andrey Bekker at the University of Manitoba, Canada.
The idea for the study was a direct consequence of the 2011 Nature paper by Planavsky, Scott, Lyons and others that challenged the hypothesis of broadly sulfidic oceans.
The international collaboration received funding for the study from numerous sources. In the U.S., funding came from the National Science Foundation, the NASA Astrobiology Institute and the Agouron Institute.
The University of California, Riverside (www.ucr.edu) is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment has exceeded 21,000 students. The campus will open a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Center. The campus has an annual statewide economic impact of more than $1 billion. A broadcast studio with fiber cable to the AT&T Hollywood hub is available for live or taped interviews. UCR also has ISDN for radio interviews. To learn more, call (951) UCR-NEWS.
New data challenge old views about evolution of early life
UC Riverside-led research team rules out zinc as a factor in the delayed diversification of single-celled and multicellular organisms
2012-12-24
ELSE PRESS RELEASES FROM THIS DATE:
'Molecular levers' may make materials better
2012-12-24
DURHAM, NC -- In a forced game of molecular tug-of war, some strings of atoms can act like a lever, accelerating reactions 1000 times faster than other molecules. The discovery suggests that scientists could use these molecular levers to drive chemical and mechanical reactivity among atoms and ultimately engineer more efficient materials.
"We are interested in designing new, stress-responsive materials, so we are trying to develop reactions that are very slow normally but that can be accelerated efficiently by force," said Duke chemist Steve Craig, who headed the research.
In ...
Mount Sinai survey shows that nearly 1 in 3 children with food allergies experience bullying
2012-12-24
Nearly a third of children diagnosed with food allergies who participated in a recent study are bullied, according to researchers at the Icahn School of Medicine at Mount Sinai. Almost eight percent of children in the U.S. are allergic to foods such as peanuts, tree-nuts, milk, eggs, and shellfish.
Nearly half of parents surveyed (47.9 percent) were not aware of the bullying—although both the bullied children and their parents reported experiencing higher stress levels and lower quality of life.
The study, titled, "Child and Parental Reports of Bullying in a Consecutive ...
Thousands of Businesses and Homeowners Could Reduce Electricity and Natural Gas Prices Over the Winter Months by Using TSI ENERGY
2012-12-24
With the combination of steep escalation in utility prices and current economic climate, the price that a businesses and homeowners pay for electricity and natural gas can mean the difference between make and break for their bottom line
With electricity prices set to reach a record high this winter, TSI ENERGY has launched a new website to help businesses find the most competitive rates for their business electricity supply. Aimed at helping companies based in the USA obtain the most competitive pricing. TSI ENERGY understands that the volatile market place can be difficult ...
Dream Couture Fashion Studio
2012-12-24
Conveniently located at 812 Britannia Rd. W, heartland mall Unit 107 (Near Mavis and Britannia), Missisauga, Ontario, Dream Couture Fashion Studio offers unique collections both catering to the Eastern and Western communities with the promise that any outfit you dream can be designed and created.
With the cultural diversity that makes Canada, especially Toronto the global symbol of multicultarism Dream Couture shows how it embraces this diversity with style. Whether it is a Bridal Gown or a Saree or Lehngas flattering today's Bride, Dream Couture can help to create ...
Tumblecaps Retro is Getting Ready for the Holidays!
2012-12-24
Loveland, Colorado - Tumblecaps Retro, released this year by Cerulean Games, will be receiving an update in time for the holiday season featuring bug-fixes and user requests, along with some holiday fun.
"We love the holidays!" Stated Dave Calabrese, CEO of Cerulean Games. "Tumblecaps Retro has been wonderfully received by the public, and it's time to start giving the game some additional content."
The Winter update will include various bug-fixes and an all new Holiday themed Cap Pack with new visual FX, new pixelated bottlecaps, and a new Holiday ...
Producer Jonathan Isen Teams Up With Steve "Spaz" Williams To Produce An 8 Spot Campaign For Radio Shack
2012-12-24
Following up on his 23 spot package for Radio Shack's Christmas campaign, producer Jonathan Isen solicited the services of world-class director Steve "Spaz" Williams to produce an 8 spot package highlighting the post Christmas phone upgrades available at Radio Shack through Grey/NY and Grey/Wing.
Shooting on location in New Rochelle, New York, Williams brought his comedic expertise to "real life" situations in store. The shoot reunited Williams with Grey ECD Jeff Odiorne.
"It was like no time had passed. We just picked up right where we left ...
Zaahib Inc Receives Approval to Commence its Business is Saudi Arabia
2012-12-24
Zaahib Inc LLC, has received approval from the Saudi Arabia Ministry of Commerce & Industry, to commence its business in Saudi Arabia, according to Zaahib CEO, Mr. Waleed Alrashoud.
Mr. Alrashoud has stated that as eMarketing has become a corner stone in today's world, Zaahib.com will be a leading provider in Saudi Arabia, reaching its customers with an innovative set of added-value services, including map-based search for properties, and smart property management tools.
Zaahib will be providing these services via their website: Zaahib.com, enabling customers ...
VoiceNation Launches "Operation Give Back"
2012-12-24
VoiceNation, the industry leader in live answering and virtual receptionist services, has launched Operation Give Back, a program to ensure local children living in shelters and those in need of assistance receive gifts this holiday season.
VoiceNation's president Jay Reeder provided each of his employees with resources to support a child. Each employee was provided with an informational packet for a child, which included the child's holiday wish list and the funds to purchase gifts.
VoiceNation donated 146 gifts to four organizations within the local community to ...
The Difference between Custom-Made Cabinets and RTA Cabinets Ventura
2012-12-24
Many people don't realize that there is actually a difference between an RTA Cabinets Ventura and a custom-made cabinet. They think that both cabinets are expensive and that both of them are exclusively designed for a certain individual. This is where most people go wrong. There is quite a difference when one talked about custom-made cabinets while the other prefers a ready-to-assemble cabinet. It's not only the prices that differ. The styles, the delivery dates and the ease of installation will all play a part in helping you make this choice.
Custom-made cabinets
Custom-made ...
Equatorial Guinea: 2012 Convener of the Year
2012-12-24
New York City based South African Arts International, Ltd. is proud to announced that the Republic of Equatorial Guinea has been selected for the 2012 Convener of the Year.
This newly awarded accolade is being bestowed to a country that has showed great skill, courage and humanity in bringing Heads of State, government officials, International Humanitarian Agencies, Non Governmental Agencies, International Sports Governing Body's, Artists, Artisans, Intellectuals and the Diaspora together.
"H.E. Obiang, President of Equatorial Guinea, has mastered the Art of ...
LAST 30 PRESS RELEASES:
Are lifetimes of big appliances really shrinking?
Pink skies
Monkeys are world’s best yodellers - new research
Key differences between visual- and memory-led Alzheimer’s discovered
% weight loss targets in obesity management – is this the wrong objective?
An app can change how you see yourself at work
NYC speed cameras take six months to change driver behavior, effects vary by neighborhood, new study reveals
New research shows that propaganda is on the rise in China
Even the richest Americans face shorter lifespans than their European counterparts, study finds
Novel genes linked to rare childhood diarrhea
New computer model reveals how Bronze Age Scandinavians could have crossed the sea
Novel point-of-care technology delivers accurate HIV results in minutes
Researchers reveal key brain differences to explain why Ritalin helps improve focus in some more than others
Study finds nearly five-fold increase in hospitalizations for common cause of stroke
Study reveals how alcohol abuse damages cognition
Medicinal cannabis is linked to long-term benefits in health-related quality of life
Microplastics detected in cat placentas and fetuses during early pregnancy
Ancient amphibians as big as alligators died in mass mortality event in Triassic Wyoming
Scientists uncover the first clear evidence of air sacs in the fossilized bones of alvarezsaurian dinosaurs: the "hollow bones" which help modern day birds to fly
Alcohol makes male flies sexy
TB patients globally often incur "catastrophic costs" of up to $11,329 USD, despite many countries offering free treatment, with predominant drivers of cost being hospitalization and loss of income
Study links teen girls’ screen time to sleep disruptions and depression
Scientists unveil starfish-inspired wearable tech for heart monitoring
Footprints reveal prehistoric Scottish lagoons were stomping grounds for giant Jurassic dinosaurs
AI effectively predicts dementia risk in American Indian/Alaska Native elders
First guideline on newborn screening for cystic fibrosis calls for changes in practice to improve outcomes
Existing international law can help secure peace and security in outer space, study shows
Pinning down the process of West Nile virus transmission
UTA-backed research tackles health challenges across ages
In pancreatic cancer, a race against time
[Press-News.org] New data challenge old views about evolution of early lifeUC Riverside-led research team rules out zinc as a factor in the delayed diversification of single-celled and multicellular organisms