IF, at the very beginning of life there was no oxygen then HOW ?

Question

did life, that requires oxygen, start. ie: All living things need oxygen, including plant life, and plants make oxygen during daylight hours, Yes ?, but what gave plant forms, the oxygen that they required before they could even exist. Hey! come on you clever little so & so's.

Answer 1

Why do so many answers here say that plants don't need oxygen? They absolutely DO need oxygen. They photosynthesise to produce the carbohydrates, and generate oxygen as a waste product, but then what do they do with the carbohydrates? They carry out respiration to provide the energy they require, and to do that they need oxygen!

The person who said organisms on hydrothermal vents are using oxygen from the sun is talking rubbish too, since the basis for life down there is anaerobic bacterial colonies that metabolise compounds such as sulphides and methane. There is virtually no oxygen in the water at those depths.

As to the orignial question, early life forms produced molecular oxygen as a waste product, at which point those few organisms that happened to be able to make use of oxygen but were not totally dependent on it thrived and developed, while many others were poisoned by it, thus changing the balance of life on the planet.

Answer 2

Oxygen is poisonous to some bacteria. These are probably the most like the early life on earth. Then blue/green algae and plants came along and made the oxygen and wrecked the planet for these bacteria. They had to go into hiding to survive. When the oxygen was there then it could support the other animals.

So kids. Next time there is a program that shows spiders and shrimps living on a thermal vent or underground chemical vent and they say that animal life without the sun is possible shout out "Rubbish!". Point out the fact that these jolly animals are breathing oxygen made using the sun's energy. Without the sun, they would not be alive.

Answer 3

Sorry, but oxygen was always present,especially at the beginning of life. What you may be thinking of, is, that of the formation of oxygen in the atmosphere. The gases of primitive earth was similar to the current atmosphere of Jupiter: consisting of carbon, nitrogen,and oxygen atoms combined with hydrogen in the form of a methane-ammonia atmosphere. The pre-cambrian era lasted 4000 million years, at its end, about 600 million years ago, the first critical level of a oxygen atmosphere evolved, and the first oxygen using organisms evolved,too; (before that time many unicellular organism would have been killed by oxygen). Over the next 150 million years, the first invertebrates, and then vertebrates(fish), evolved. The second critical level of oxygen in the atmosphere was reached at about 425 million years ago, and it was at that time that the first land plants evolved. The age of the dinosaurs followed, and the rest is history. The current composition of the atmosphere is 78% Nitrogen (N2), 21% oxygen (O2), and 1% Argon (A)--there are small amounts of CO2, H2O, Ne, and He, also present. Life started in the primitive ocean of ammonia/methane from electric sparks from lightening discharges, free oxygen would have been poisonous to these early organic molecules, which took four billion years to start the Paleozoic Era, which lasted for another 400 million year to start the age of the dinosaurs (lasting another 150 million years)-- the age of giant mammals followed (another 50 million years) that brings us up to the million or so years of advanced primates and humans.

Answer 4

Listen up. Oxygen is a WASTE PRODUCT of photosynthesis. Early plants could use Carbon dioxide and sunlight to produce sugars to use for food. Oxygen was their waste product.. Like crap if you don't understand the term. or Sh*t. Earlier yeast like organisms were adapted to living in a carbon dioxide atmosphere. As plants prospered, they emitted more and more oxygen into the atomsphere. To the yeasts this was a poisonous gas and most of them died. The oxygen is broken down from carbon dioxide ( co2) Do you notice the two oxygen molecules in that carbon dioxide molecule. Great. Oxygen is just another element. It combines well with things and a couple of billion years ago it was a deadly poison. Animals developed that could use oxygen in their respiration. Sort of like todays bacteria that develop an immunity to antibiotics. Those that can reproduce. Those who can't die. Natural selection favored those who could since there was lots of oxygen due to all those pesky plants.

Answer 5

If your question was actually legitimate you'd think somebody would have taken that little speed bump into consideration, wouldn't you?

As it turns out, the first bacteria (if I recall my schooling correctly) were anaerobic: they did not need oxygen, and in fact oxygen was poisonous to them. When critters that spewed oxygen into the atmosphere as a by-product finally got around to evolving, they killed off most of the anaerobic bacteria, which at that time was most of life on earth.

I suppose you were trying to be clever, but you really ought to research your supposedly caustic barbs a little more thoroughly before you post them.

Answer 6

Your question is nonsensical because:

a) oxygen has been around a lot longer than any living being

b) not all life forms require oxygen

c) our particular species evolved over a long period of time to require oxygen - in the beginning, as microbes, we did not

You do know, surely, that the universe and it's component elements and compounds were around for a long, long time before any life evolved, yes?

Answer 7

Not every single life form takes oxygen. Organisms use what elements and nutrients are around them to live. When certain organisms started producing oxygen as a byproduct, other organisms started living off it it.

Answer 8

Plants do not need oxygen, what they need is carbon dioxide in order to photosynthesize.As a result of photosynthesis Oxygen was then produced (photosynthesis-->process of using energy in sunlight to convert water and carbon dioxide into carbohydrates and oxygen)..The oxygen produced then allowed other organisms that need oxygen to evolve...first the microscopic single cellular ones and then through continuous mitosis etcetera, more complicated organisms evolved...

Answer 9

Early bacterial life does not require oxygen to live, but produces oxygen as a waste product.

Answer 10

buddy all life forms dont need oxygen
in fact in the early stages of evolution-- aeons ago-- the atmosphere is supposed to have CO, CH4 mainly- the life forms as we know them simply did not exist. Photosynthesis was not possible - as there was abundant CO, CH4 but hardly any CO2.

certain micro organisms-- which lived off complex metal oxides are supposed to pre-date the carbon based bio forms. Their bodies were composed mailnly of specific metals. metallic compounds-- the death of colonies of these is supposed to have created deposits of metals viz iron, copper, et al.

in the process of assimilating energy from the complex compounds- quantities of oxygen were liberated- which then combined with CO, CH4 et al to generate organic compounds which again led to the birth of organic[carbon based] life forms.