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49

The answer to your question is yes it is certainly possible. At one time it was thought that there was something special about "organic" chemicals which meant that they could not be artificially synthesised out of fundamental elements. In 1828 Frederick Wöhler synthesised urea (CO(NH2)2) which is often taken as the first demonstration that the organic v ...


34

Living organisms can be divided into hetrotrophs and autotrophs. Autotrophs like plants and algae are able to produce complex organic compounds from relatively simple inorganic components. They are satisfied with sunlight, water and other abiotic stuff and do not need to consume "life". We -- along with all other animals -- are not autotrophs, but ...


31

Why do we age is a classical question in Evolutionary Biology. There are several things to consider when we think of how genes that cause disease, aging, and death to evolve. One explanation for the evolution of aging is the mutation accumulation (MA) hypothesis. This hypothesis by P. Medawar states that mutations causing late life deleterious (damaging) ...


19

Even on a purely synthetic diet, your body would still use living cells as an energy source. Our bodies contain more bacterial cells than human, mostly contained in our gut. These microbes process any nutrients we ingest and when they die, we absorb their cellular components as nutrition. The lining of the gut is the most rapidly dividing population of ...


14

Your question is phrased somewhat ambiguously as to whether you're asking about the theoretical possibility, the feasibility, or the practical ability in everyday life. 1) Theoretically, yes. It is chemically possible to produce all substances that humans need to survive without the use of living organisms in the process. In the end, biological systems use ...


13

This is a very good question. There is a big ongoing field of research called "evolution of aging/senescence" that tackles this question. I won't give you a complete overview of the different hypothesis the could explain why we age but here is a fundamental concept that is to know. We'll assume that there is some extrinsic mortality, mortality against ...


10

Actually, genetically, there is no reason for animals to continue to exist after they have procreated. If you look at salmon, they die immediately after procreating, which is probably the most efficient way to carry the best genes to the next generation. In the case of mammals, they need to teach their offspring where to find food, where to find water and ...


9

The definition of life is a controversy in itself, and as it is simply a word that can be understood by everyone however they wish, there is no "correct" definition. It is thus not really possible to give a "correct" answer to your question, but here are a list of things you may want to consider: Replication of DNA is probably the most agreed common ...


9

Because evolution isn't about individuals: it's about species. What matters to natural selection isn't how long you live, but how many grandchildren you have. A long lifespan can be an evolutionary advantage, but like any trait, it's only an advantage to the extent that allows you to reproduce more. It would seem that a longer lifespan would be advantageous ...


9

Depends on how you define "life"? Is unfertilized chicken eggs alive? What about cow milk? Well there are bacteria in it. What if you get rid of that bacteria? Then some people would not be able to utilize lactose... Also as Bez mentioned rice grains are quiescent, meaning they are in a dormant state and not really "alive" but again depends on how you ...


8

The definition of life is the main issue here. That is one of the great philosophical questions in Biology (and not only Biology) and is way beyond the simple Q&A format of this site. However, most definitions of life can be boiled down to1: A self replicating entity that interacts2 with its environment. Or, even more simply [1]: Life is ...


7

Depends on what kind of life you want! The Database of Essential Genes lists genes essential for life for a number of species, although I would be wary of some of the numbers; bacterial results are probably more reliable but it lists 118 for humans and 2114 for mice. There are a bunch of different numbers for different E. coli strains, with larger numbers ...


7

How can really even draw a defined line of what life is? It's easy, really: just make one. In the answer I linked to I go into the reasons why viruses aren't alive (spoiler alert: no ribosomes) and what our current definition is, but the bigger question is why does it matter? We can draw the line wherever we want to, but it's still an arbitrary ...


7

Question: Is it possible for humans to live healthy long lives without eating any type of life, i.e no animals, no plants? First, according to a definition of a living organism(biology-online), milk is not live, because it does not have an ability to reproduce itself, among other... My claim: If you consider milk and honey non-live (no DNA), then, yes, ...


6

It may never have happened again, however, since all lifeforms on Earth today are similar on a molecular level (DNA), suggesting a common origin. An important distinction to make here is that all extant life on Earth has a common origin. It's completely possible that abiogenesis occurred many times, but whatever organisms emerged as a result became ...


6

No. It is possible but extraordinarily impractical to nourish yourself without killing animals, plants or even bacteria, as many have explained in detail. However, your immune system constantly kills pathogens that infect your body. What's worse, the macrophages literally catch and eat these bacteria alive, so you are very much "consuming" them. You could ...


5

In men, gout is associated with a higher risk of death from all causes. This would imply that their life expectancy is shorter. From a review by Kim et al. (1): Among men who did not have pre-existing coronary heart disease, the increased mortality risk is due primarily to an elevated risk of cardiovascular death, particularly from coronary heart ...


5

OK, so we know a couple of things about life in the universe. Note, however, that this is not really an answer and is also not very biological in nature. So, we don't know how life began on the Earth. However, do know that: (1) The probability of life evolving on a planet in the universe is non-zero (since we exist) and, (2) So far, we have not found ...


4

...many biologist/scientists say that viruses are not living because everything they do is just chemicals carrying out their predefined chemistry. I don't think that's correct. Many definitions of life exclude viruses because they lack the apparatus to perform the life functions themselves, especially reproduction. They don't seem to qualify as ...


4

It may be feasible to live without consuming anything that was alive, but it would be incredible difficult. For example, all humans need to consume glucose to survive. Glucose is the only food source used by cells in the brain. Plants are the easiest source of food source for glucose. If we can't get glucose from plants, then we would need to synthesize it ...


4

Well, technically if you are eating something from a plant or animal without killing that plant or animal, then technically you would not be "consuming life" as nothing as been killed. Fruits, for example, can be removed from the tree without harming it and in fact are meant to be removed as that is how the tree reproduces. Ditto with berries, melons, ...


3

You're probably thinking of the Spiegelman Monster. It was actually discovered in 1965, but it was discovered that it became shorter over time in 1997. It also wasn't included in that thread, and it has a strange name. http://en.wikipedia.org/wiki/Spiegelman_Monster


3

Yes, research studies that were conducted have found that methanogens (microorganisms) are able to survive in conditions similar to Mars (reference). Another study conducted has also concluded that some lichen and cyanobacteria is also capable of survival. Surprisingly, they were also found to be active (reference). There is speculation now on whether ...


3

There are wikipedia pages on Geological history of oxygenation and on Great Oxygenation Event I don't know much about geology and someone else might be able to give an exhaustive list of evidence (and method of measuring) concerning the oxygen concentration on earth but that would be a very long answer I guess! Rather than a full answer, I give you a list ...


3

Yes. The Bristlecone Pine, Pinus longaeva, is one example. This species boasts the oldest individual living organisms, and also has been convincingly argued by Lanner and Connor (2001) to show no evidence of senescence. While the Wikipedia page on Biological Immortality (as of June 2013) unfortunately ignores plants, the pages on Negligible Senescence and ...


3

Its not scientifically or logically possible to say 'this is impossible' but since this is a speculative question, I'll hazard an opinion. I'd like to argue that, at Earth standard pressure temperature and atmospheric conditions, C H O and N are not really replaceable. Throw water into the mix as the most common liquid and replacing any or all of these ...


3

News to me is that about 4500 of the 4900 minerals on Earth have been created by life. After reading the article, this isn't what was said. What was said is that life increases mineral diversity on a planet, most notably through biproducts reacting with existing minerals (like Oxygen - a biproduct of photosynthesis - reacting with iron to create ...


3

The question of what is living is nothing but a matter of definition. We can only tell you what are the standard definitions of what is a living thing but no absolute truth exist behind these definitions. Therefore, I am afraid that all discussions here will bring anything new to your ethic or religion related discussion. I want to argue that the @user137's ...


3

Damn.. this is getting into a huge debate. There are different levels of life. What we mean by living when we say living is generally an Organism. This is highly debatable. If you say viruses are nonliving because they need a host then almost every hetertroph is nonliving because they need the support of autotrophs. An organ is living as long as it ...


2

According to this, 1.2% of stars have planets that can support life. According to Google, there are 300,000,000,000 stars in the Milky Way. That means 3,600,000 stars can support life. Each of these stars is estimated to have 1-2 planets that can support life. For the sake of simplicity, I'll use 1.5 to represent this, since it is the average of 1 and 2. ...



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