Sentences with phrase «oxygen levels rose»

Once oxygen levels rose past this low level, predation likely provided a strong incentive for animals to get bigger and more complicated, and to develop new body plans.

But why did life not explode when oxygen levels rose dramatically 2.1 billion years ago?

The presence of the same types of materials on Mars suggests that oxygen levels rose there, too, before declining to their present values.

It had been suggested that only when oxygen levels rose to above 17 % (it is 21 % today) that widespread fires would be found.

According to Lyons, the solution may be that oxygen levels rose to perhaps 2 % or 3 % of modern levels around 800 million years ago.

Not exact matches

The continued rising levels of imports of foreign steel threaten to impair the national security by placing the U.S. steel industry at substantial risk of displacing the basic oxygen furnace and other steelmaking capacity, and the related supply chain needed to produce steel for critical infrastructure and national defense.

When babies rouse, oxygen levels and heart rates rise, which is good for brain growth and development and immune functioning.

The textbooks will tell you that oxygen levels began climbing soon after photosynthesis evolved, but we now know that some cells started photosynthesising as long as 3.4 billion years ago, long before oxygen levels began to rise.

Researchers working in Papua New Guinea think they may have been wiped out when the level of oxygen in the oceans rose dramatically, stimulating the evolution of oxygen - hungry fish that simply out - competed the ammonites for resources.

«If oxygen levels were 3 % and they rose past that 10 % threshold, that would have had a huge influence on early animal evolution,» he says.

Scientists say reserves can help marine ecosystems and people adapt to five key impacts of climate change: ocean acidification; sea - level rise; increased intensity of storms; shifts in species distribution, and decreased productivity and oxygen availability.

The increasing concentration of oxygen in the atmosphere eventually overwhelmed the control on oxygen and meant it could finally rise to the levels we are used to today.

Professor Tim Lenton and Dr Stuart Daines of the University of Exeter Geography department, created a computer model to explain how oxygen stabilised at low levels and failed to rise any further, despite oxygen already being produced by early photosynthesis.

«Oxygen levels and the rise of fire: New research reveals extensive wildfires occurred significantly later than previously thought as a result of changes in oxygen levels.&Oxygen levels and the rise of fire: New research reveals extensive wildfires occurred significantly later than previously thought as a result of changes in oxygen levels.&oxygen levels.»

Oxygen levels in certain ocean regions are dropping, adding a third stressor to acidification and temperature rise.

Dipping oxygen (O2) levels and rising carbon dioxide (CO2) levels in the blood alert the sleeping brain to the problem, rousing the sleeper just long enough to re-establish breathing.

Here on Earth, we had lots of water but no widespread deposits of manganese oxides until after the oxygen levels in our atmosphere rose.»

Oxygen levels in the atmosphere did not rise until at least 400 million years after the origin of oxygen - producing bacOxygen levels in the atmosphere did not rise until at least 400 million years after the origin of oxygen - producing bacoxygen - producing bacteria.

A new study found that vulnerability of deep - sea biodiversity to climate change's triple threat — rising water temperatures, and decreased oxygen, and pH levels — is not uniform across the world's oceans.

Exposure to low - oxygen air sends EPO levels soaring in normal mice, but these conditions did not induce a rise in the hormone in the animals without HIF - 1α, the researchers report in the 18 April issue of Cell.

In this way, the system formed a negative feedback loop that automatically slowed the rise in oxygen levels as the levels increased.

The technique relies on the observation that when activity in an area of the brain increases, blood - oxygen levels in that region rise, which modulates the MRI signal.

«That threshold was in the range of a 10 to 40 percent increase, and was the second time in Earth's history that oxygen levels significantly rose.»

They found that if mice exposed to bloodstream infections were given a drug that mimics the effect of low oxygen, levels of HIF2alpha and VE - PTP rose and their blood vessels became less leaky.

Beyond the sea level rise itself, the ancient geologic and geographic changes probably led to a buildup of oxygen in the atmosphere and a change in ocean chemistry, allowing more complex life - forms to evolve, he said.

Two billion years ago, around the time atmospheric oxygen levels were rising, one cell engulfed another, and instead of becoming lunch, the ingestee became an Earth - changer and, eventually, a vital part of you: mitochondria.These microscopic cell inhabitants / engines allowed their host cell to suddenly begin to burn oxygen when digesting their food, an energy source that vastly expanded the amount of energy they could harvest from a given morsel of food.

© Wim van Egmond (Photo from Ciliates, used with permission) As the level of oxygen in the atmosphere rose, however, most surface lifeforms on Earth became oxygen breathing, such as these two single - celled protoctists (Euplotes, left, and Stylonychia) which move with hairlike cilia.

Although the Cambrian explosion generated a large number of new phyla of Earth - type life, it actually crashed in a mass extinction not long after it began when oxygen levels fell and hydrogen sulphide levels rose again so that biodiversity at the family, genus, and species levels was decreasing around 515 million years ago (Gill et al, 2011; and Michael Marshall, New Scientist, January 5, 2011).

The melting of Snowball Earth glaciers apparently released phosphates ground off continental rocks into the oceans between 750 and 620 million years ago, causing levels of this vital nutrient to rise to levels higher than experienced before or since, and feeding oxygen - producing life which eventually supported the rise of newly developing oxygen - consuming «metazoans,» or animals (staff, New Scientist, October 27, 2010; and Planavsky et al, 2010).

Eukaryotes became multicellular in the precambrian at the same time earth's oxygen levels were rising.

The symptoms from those events (huge and rapid carbon emissions, a big rapid jump in global temperatures, rising sea levels, ocean acidification, widespread oxygen - starved zones in the oceans) are all happening today with human - caused climate change.

These theories proclaiming the cause of muscle fatigue do not make sense if we just consider that, if the levels of oxygen or ATP falls below the level necessary for muscle contraction, or lactate levels rise too high, an athlete would not just slow down but stop performing, and even collapse since muscles would be unable to maintain a standing posture.

It is a system to detect levels of oxygen, carbon dioxide in the close car and open windows when the level of oxygen drops or the carbon dioxide level rises, thus prevents accidental deaths in children or pets locked inside a car.

That means a 12.42 mile Hill Climb with 156 corners rising 14,000 feet, at which point both car and driver struggle to breathe efficiently as oxygen levels drop to just 58 per cent of normal.

Pikes Peak is an unforgiving Hill Climb, spanning 12.42 miles and 156 corners, rising to 4,300 meters above sea level with oxygen levels at the -LSB-...]

These fish would likely go extinct even if climate change were particularly slow — once the temperature of the Arctic and Antarctic Oceans rise above the level that the water is unable to carry sufficient oxygen.

A Lacis: by the time we have to worry about oxygen levels we will be out of fossil fuels and unless we invent a battery we will be worrying about nuclear waste and learning Tibetan as sea level rises.

Rather, the rising levels of oxygen in the oceans became the trigger for complex life - forms to attain mobility and features of modern animals.

Yet the study is a trailblazer in terms of making a distinction between waters with high and low levels of oxygen in supporting the rise of complex organisms.

The study, published in the journal Nature Communications, tender geochemical evidence that a rise in oxygen levels in the oceans coincided with the appearance of complex animals.

Rising levels of oxygen in the oceans were a key causative factor in the emergence of skeletal animals 550 million years ago, according to a new study.

The lower Chesapeake Bay is especially at risk due to high rates of sinking land (known as subsidence).96 Climate change and sea level rise are also likely to cause a number of ecological impacts, including declining water quality and clarity, increases in harmful algae and low oxygen (hypoxia) events, decreases in a number of species including eelgrass and seagrass beds, and changing interactions among trophic levels (positions in the food chain) leading to an increase in subtropical fish and shellfish species in the bay.66

«Significant environmental changes, such as sea level and sea temperature rise, oxygen depletion and ocean acidification, will dramatically change the landscape, restructuring an array of natural and physical assets as well as cultural and economic,» said Judith Kidlow of the National Ocean Economics Program.

I am starting an oxygen market with the premise that oxygen is destroyed everytime you burn fossil fuels and there may be one day dangerously low levels of oxygen as the CO2 concentration rises.

31) Despite activist concerns over CO2 levels, rising CO2 levels of some so - called «greenhouse gases» may be contributing to higher oxygen levels and global cooling, not warming

As Howard Lee wrote in the Guardian in August, «Geologically fast build - up of greenhouse gas linked to warming, rising sea - levels, widespread oxygen - starved ocean dead zones and ocean acidification are fairly consistent across the mass extinction events, and those same symptoms are happening today as a result of human - driven climate change.»

Rising temps are generally equated with increases in global oxygen levels, which animals need to live.