Photosynthesis Unleashes Chemical Superweapon: Oxygen

Photosynthesis originated as a genetic mutation that allowed simple cyanobacteria to produce their own food source with only the power of the sun. However, the resulting waste product of this process, oxygen, was toxic to almost all life on the young planet. This oxygen created by cyanobacteria's new superpower also reacted with the existing atmosphere and caused a dramatic period of cold climate known as "Snowball Earth." When the planet emerged from this icy condition 200 million years later, the life that remained found itself in a warm, oxygen-rich environment perfect for the evolution of multicellular organisms.

Watch full episodes:

Subscribe to Science Channel:

Check out SCI2 for infinitely awesome science videos. Every day.

Download the TestTube app:

[LexoG]

I know it's easier to communicate the concept as saying photosynthesis arose as a single mutation, but that's biologically inaccurate. It may have evolved once, in a single lineage, but it was the culmination of the many mutations that it takes to produce the functional cellular machinery that harvests the energy from photons of a particular wavelength to strip electrons from water molecules.

[neosaneo]

i love how excited everyone is in this video

[asyatomlinsonn]

I just love science, you learn new things each day and I also love this channel

[whatabouttheearth]

Well, I get its mainstream 'PopSci" but, the cyanobacteria were not the first to do photosynthesis and the earliest forms of photosynthesis did not produce oxygen as a waste product, nor do all forms of photosynthesis extant today. And "snowball earth" is also misleading when reffering to the Proterozoic.

[wendys]

I didn't know reptiles could evolve into mammals.

[frogpalpeeper]

My own word for the origin of photosynthesis is "magagoopalah". It sounds like something big and it's kind of fun to say.

[rolo]

So what did the cyano bacteria eat before it developed photosynthesis powers?

[kernellbcn]

I thought iceball earth was a hypothesis that some scientists proposed. Is it accepted now as a scientific theory?

[PiotrMagpie]

I hate when scientist think about mutations as a "mistake" - no its not! it's all calculated deep within.

[ashok]

what happen the gravity of the earth if all the water molucule is gone from around the earth?

[DonaldSleightholme]

do plants actually produce oxygen or are they just separating the hydrogen and oxygen from water and using the hydrogen as fuel and expelled the oxygen as waste? 🤷‍♂️

[merounkidi]

San Antonio Middlefield road, arco, Palo Alto

[emperorpalpatine]

This sounds like an alien documentary for me. Hahahaha

[kevinnguyen]

"Just 2 thousand years ago humans walked the Earth"???? Um in pretty sure humans have been living before 2000 years.

[WonderfulBoness]

Well I'm kind of feeling good about climate change, thanks cyanao bacteria😀.

[efrenlaboy]

My respect but no one knows way or when human appear

[diGritz]

Astronomers explaining biology. Alrighty then. Stick to Astronomy and get some real Biologists next time.

[anserch.]

Do you have proof of Evolution? Can you show me one direct observable fact "that fish were converted into reptiles"? Can you show me the Stages?

[kernellbcn]

I thought iceball earth was a hypothesis that some scientists proposed. Is it accepted now as a scientific theory?