Khristeeanos said:
How do athiests believe that life came from non-living materials and what do they call it?
Please give an answer in layman's terms as you did in this post.
I am a high school dropout.
Hi Khristeeanos
I like your nickname BTW
First of all, I am not an athiest. Worse, I am a Catholic. Just kidding.
I am going to take the liberty of addressing the question as long as it is clear that I am answering "how do
scientists believe that life came from non-living materials". I cannot speak for athiests, but I am assuming that athiests accept the latest scientific research.
Before I get right to your question lets talk about the concept of "life".
First of all, what we call life violates none of the fundamental principles of chemistry or physics. While complex and amazing there is nothing metaphysical about life. Physical life if a process of the physical world.
As far as defining life from non-life the distinction is not as easy as it may appear. Certainly, you and I are alive but the molecules and chemicals that make up or body are not. It is the complex interactions (biochemistry) of these chemicals that make us alive.
Even at the biochemical level - the level of chemical interactions - I would not call it life. Many biochemical reactions, like replication of DNA, respiration, and other metaboilc process can be done in the test tube. They are following the same chemical pathways as theydo in our bodies, but I don't think anybody would consider that DNA replication on the lab to be alive.
So what is life?
The standard definition of life goes has the following requirements:
* metabolism (bacially that means ongoing chemical reactions)
* growth
* reproduction
* response to stimuli or adaptation (sometimes called irritibility)
Think about this. FIRE has many of the requriements for life. It has a simple metabolism (ongoing chemical reaction between the fuel and oxygen), it grows (like a forest fire that started from a cigarette ), and it responds to it's environment (cut off the oxygen and it dies,)
Now of course nobody says that fire is alive, but you see how a simple chemical process can have some of the requirements.
Take the humble virus. THey cause colds and AIDS and the flu and are very common and well known. VIrus actually fall right on the boundry between non-life and life! Thats right, it is actually debatable among scientists as to whether a virus is alive or not.
That goes to show that life vs non life is not so clear cut.
NOW TO FINALLY ANSWER YOUR QUESTION
THe most current scientific theory about how life arose is called Abiogenesis.
There are a number of different competing theories about the specific detalils, but there is a general consensus.
Abiogensis thoery proposes that in the early Earth chemical reactions and interactions were going on on a global basis (around the world). These chemical reactions were fuelled by geothermal vents like those found at the bottom of the ocean in certain areas today. Some of these chemicals included molecules that were capable of self replication. Not that unusual, self replicating molecules do exist.
Self replicating molecules are not enough, however. Now we get to "protocells". Protocells are basically half way between living cells and self replicating molecules. Protocells have been made in the lab, but they are not quite "alive". Close, but not quite.
It is at the level of these protocells that the evolutionary process kicks in. Protocells consume each other. Those that were more efficient consumed those that were less efficient and replicated themselves. Somewhere down the line you cross that fuzzy boundry between nonliving protocells to living cells.
The transition from nonlife to life was more like a sunrise then flicking on a light switch.
There was no "first living cell" anymore then there was a "first Englishman" or a "first person to speak French".
Also, this was an ongoing process around much of the earth. Not just an isolated little pool.
So why don't protocells occur today in nature? Well basically, the chemical condidions necessary for them to exist would essencially be fertilizer for existing life forms. They just don't stand a chance of existance in nature anymore.
So I hope that answers your question.
The difference between abiogenesis and spontaneous generation (SG) is that SG is the idea that FULLY FORMED ORGANISMS spring into existance. Abiogenesis is more like a prolonged, large scale transition with several stages.
I know that won't be enough to convince you. Hopefully you will be more informed about your debate opponenst real opinions.
Peace.