Social Media Sidebar

Announcement

Please sign up, comment on articles and bring your friends!

Current poll

PlanetTech is asking:

What do you think about our new web site?

Love it, indeed
Really good solution
Same as old one
The old one was better
This is a new option

Quote of the day

People say we're running out of energy. That's only true if we stick with these old 19th century technologies. We are awash in energy from sunlight.

 

Ray Kurzweil

 

Have We Been Wrong About the Origins of Life?

RATE THIS! +8
Posted in Science on 19th Aug, 2016 04:11 AM by AlexMuller

For nearly nine decades, science’s favorite explanation for the origin of life has been the “primordial soup.” This is the idea that life began from a series of chemical reactions in a warm pond on Earth’s surface, triggered by an external energy source such as lightning strike or ultraviolet (UV) light.

 

But recent research adds weight to an alternative idea, that life arose deep in the ocean within warm, rocky structures called hydrothermal vents.

 
A study published last month in Nature Microbiology suggests the last common ancestor of all living cells fed on hydrogen gas in a hot iron-rich environment, much like that within the vents. Advocates of the conventional theory have been skeptical that these findings should change our view of the origins of life.
 
But the hydrothermal vent hypothesis, which is often described as exotic and controversial, explains how living cells evolved the ability to obtain energy, in a way that just wouldn’t have been possible in a primordial soup.
 
Life isn’t just about replicating information stored within DNA. All living things have to reproduce in order to survive, but replicating the DNA, assembling new proteins and building cells from scratch require tremendous amounts of energy. At the core of life are the mechanisms for obtaining energy from the environment, storing and continuously channeling it into cells’ key metabolic reactions.
 
Where this energy comes from and how it gets there can tell us a whole lot about the universal principles governing life’s evolution and origin. Recent studies increasingly suggest that the primordial soup was not the right kind of environment to drive the energetics of the first living cells.
 
It’s classic textbook knowledge that all life on Earth is powered by energy supplied by the sun and captured by plants, or extracted from simple compounds such as hydrogen or methane. Far less known is the fact that all life harnesses this energy in the same and quite peculiar way.
 
Life could have evolved to exploit any of the countless energy sources available on Earth, from heat or electrical discharges to naturally radioactive ores. Instead, all life forms are driven by proton concentration differences across cells' membranes. This suggests that the earliest living cells harvested energy in a similar way and that life itself arose in an environment in which proton gradients were the most accessible power source.
 
Recent studies based on sets of genes that were likely to have been present within the first living cells trace the origin of life back to deep-sea hydrothermal vents. These are porous geological structures produced by chemical reactions between solid rock and water. Alkaline fluids from the Earth’s crust flow up the vent towards the more acidic ocean water, creating natural proton concentration differences remarkably similar to those powering all living cells.
 
The studies suggest that in the earliest stages of life’s evolution, chemical reactions in primitive cells were likely driven by these non-biological proton gradients. Cells then later learned how to produce their own gradients and escaped the vents to colonize the rest of the ocean and eventually the planet.
 
While proponents of the primordial soup theory argue that electrostatic discharges or the Sun’s ultraviolet radiation drove life’s first chemical reactions, modern life is not powered by any of these volatile energy sources. Instead, at the core of life’s energy production are ion gradients across biological membranes.
 
Nothing even remotely similar could have emerged within the warm ponds of primeval broth on Earth’s surface. In these environments, chemical compounds and charged particles tend to get evenly diluted instead of forming gradients or non-equilibrium states that are so central to life.
 
Deep-sea hydrothermal vents represent the only known environment that could have created complex organic molecules with the same kind of energy-harnessing machinery as modern cells. Seeking the origins of life in the primordial soup made sense when little was known about the universal principles of life’s energetics.
 
But as our knowledge expands, it is time to embrace alternative hypotheses that recognize the importance of the energy flux driving the first biochemical reactions. These theories seamlessly bridge the gap between the energetics of living cells and non-living molecules.

Tags: lifebiologyevolutionresearchchemistry

Read original article » Back to category

Comments



 

Recent headlines

  • Posted in Medicine on 2017-08-21 19:26:00
    Darmiyan’s software detects early stages of Alzheimer’s..read more
    Posted in Business on 2017-08-21 19:20:53
    Google needs to pay Apple a fortune to remain the default.....read more
    Posted in Medicine on 2017-08-21 19:15:22
    Artificial Intelligence beats doctors at diagnosing.....read more
    Posted in Science on 2017-08-20 16:55:58
    Computer Approaches Human Skill for First Time in Mapping.....read more
    Posted in Science on 2017-08-20 16:51:23
    Researchers use polystyrene to make next-generation of.....read more
Posted in Business on 2013-10-10 01:33
China is working towards a manned lunar mission in about.....read more
Posted in Business on 2013-10-20 07:17
Spacex says China is their main competitor for commercial.....read more
Posted in Software on 2013-10-20 06:43
Pirate Bay Browser Clocks 1,000,000 Downloads..read more
Posted in Medicine on 2013-10-10 02:10
Google reportedly investing hundreds of millions into new.....read more
Posted in Medicine on 2013-10-14 03:13
Endothelial Cells Can Repair and Regenerate Organs,.....read more
Posted in Science on 01.01.2010
Spacex says China is their main competitor for commercial.....read more
Posted in Science on 01.01.2010
Staring at Your Phone Could Be Making You Short Sighted..read more
Posted in Science on 01.01.2010
Oculus Rift virtual reality headset coming to mobile, but.....read more
Posted in Science on 01.01.2010
China is working towards a manned lunar mission in about.....read more
Posted in Science on 01.01.2010
Delivering drugs via nanoparticles to target mitochondria..read more

Recent Blog Posts

  • Posted by AlexMuller
    Scientists probe Neptune's depths to reveal secrets of icy.....read more
    Posted by AlexMuller
    New terahertz imaging approach could speed up skin cancer.....read more
    Posted by AlexMuller
    Rebutting the claim that antidepressants do not work..read more
    Posted by AlexMuller
    Artificial neural networks decode brain activity during.....read more
    Posted by AlexMuller
    Four Earth-sized planets detected orbiting the nearest.....read more

Login to your Account

Login to your PlanetTech Account here

Username:
Password:
Remember me
or

Create a New Account

You just need username and password

The following errors occured:
Username:
Email:
Password:
Verify password:
Remember me