A very simple cell (seen through a microscope) like the first cells
RNA and lipid membranes
Sometime around four billion or 3.5 billion years ago, lipid membranes and RNA or DNA got together. They formed the earliest living cells on Earth. Nobody understands exactly how this happened.
What’s a lipid membrane?
What’s RNA?
What was Earth like at that time?
All our biology articles
But somehow some RNA or DNA molecules, or both, got into the water that was inside the bubbles of lipid membranes. It probably happened accidentally at first. RNA and DNA molecules just happened to be in the water where a lipid membrane was forming. But being inside lipid membranes turned out to be helpful to the RNA and DNA molecules, because the lipid membranes protected the molecules from water currents and other things and helped keep the RNA and DNA from breaking apart. These were the first cells. That’s all a really simple cell is: a big RNA or DNA molecule floating in water, surrounded by a lipid membrane that keeps it safer.
Natural selection favors the first cells
So natural selection caused more of the RNA and DNA that was inside bubbles lasted, while more of the RNA and DNA that was outside bubbles broke up into smaller pieces. After a while most of the RNA and DNA that was left was inside lipid membrane bubbles – inside cells.
What is natural selection?
How these cells reproduced
Like the RNA and DNA that were inside them, these simple cells were able to reproduce themselves. One cell could become two new cells. The cell began by using RNA molecules to make a copy of the cell’s DNA. Then, with one copy of the DNA in each half of the cell, the cell’s membrane would pinch itself in the middle and split apart, making two new cells, each pretty much the same as the old cell (except if copying mistakes had happened during the copying of the DNA).
Did you find out what you wanted to know about the first cells? Let us know in the comments!
https://quatr.us/biology/first-cells-form-evolution-biology.htm#comment-25947
Karen – thanks for sharing the current theories around how life began. I’ve been studying the thousands of nanomachines that work together in the cell and find your description lacking a lot of detail. You realize that the amount of detail you’ve left out amounts to what would be called “faith” by most people. You haven’t described how mathematically impossible what you’re asserting is, and yet you mock those who have other beliefs than you do….
Dear Mr Cronk, I’ve taken the liberty of deleting the nonsense you sent in the rest of your message, which clever people had made up in order to confuse students about science and evolution. That won’t play here: what I have to say is not faith, or religion. It is the best explanation scientists have for the facts they have observed. The article here is a simplification of the scientists’ explanation, so it’s incomplete, but you can’t understand the whole explanation without knowing a lot more chemistry and biology than our readers do. If people are interested in the details, they’ll have to learn a lot more, not from anti-evolution websites, but from science teachers and science books.
Karen – you just censored an opposing point of view and then didn’t address any part of it. …I’ve debated these things with actual biology professors and they did the same thing you did …t. I’m a software engineer who is attacking this problem from the standpoint of mathematical models, statistics, and information theory, …. Are you willing?
No. You’re not an expert, and I’m not obliged to give every crank who has a theory a platform to confuse people with. There’s no legitimate debate here. It’s not censoring – that’s when the government jails you for expressing your ideas. You are free to get your own website or twitter account and say whatever you please. You have no right to use my website to promote your ideas though. And since I did you the courtesy of using your title and last name, you can return it by using mine, if you want any more comments printed.
Dr. Carr – I apologize for not using your title. If my viewpoints were easily defeated, you could have done so in a single post…
Mr Cronk, if you actually want to find out why evolutionary biologists interpret the data as they do, please go ask a credentialed evolutionary biologist. Maybe your ideas will interest them. As you say, I am not a specialist in this subject. I am summarizing what the experts say for the benefit of younger people.
didn’t God create the world, not evolution?
Hi Kate! People used to think a god created the world long ago. You can read about that here: https://quatr.us/west-asia/whats-enuma-elish-west-asian-religion.htm and here: https://quatr.us/egypt/egyptian-god-ra.htm and here: https://quatr.us/india/whats-rig-veda-hinduism-india.htm . But for many years, scientists have known that didn’t happen. Instead, the world evolved slowly on its own. There are still a lot of people who aren’t scientists, who believe the old stories, but most religious leaders also agree now that evolution is how life got started on earth.
Hello Dr. Karen,
People either believe or don’t believe. The first life was formed with the elements of the earth. The earth was born out of the stars and the stars out of the BIG BANG.. Someone or something created the BANG where everything came out of. It might be the ‘Great Creator’, which some call God, or Allah etc. which started it all.
But for now no one really knows. And we are not even close to knowing.
Sincerely,
Francine Mayer
People either know and understand the facts, or they don’t. Believing is not part of science; that’s religion. It is not God that created the Big Bang, but physical forces, even if we don’t understand them perfectly yet.
dude where is the first “Cell” com FROM????!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
DNA OR RNA whatever
where is first nucleus com form
if you find awnser reply me at : [email protected]
Our best answer to that is on this page, Muhammed: RNA molecules found themselves inside a lipid membrane, where they were safer. Scientists are still working to find a more detailed answer; when they do, we will report it here.
“If what you mean is that only God could have created life, then most scientists disagree with you.” (Karen Carr’s reply to Greg).
I would guess there are many, many people out there who don’t accept evolution theory as the most plausible (or even probable) explanation for life in all it’s complexity as we see and experience it to this very day. Automatically these people get categorized as being stupid, ignorant, etc. As if the idea of ‘random mutations’ and ‘natural selection’ leading to utterly complex systems (like human beings) isn’t laughable at all… Why is that the ‘holy houses’ of science are not to be doubted by anyone without quickly being labeled as ‘stupid’, ‘ignorant’ (or worse)?’ This not only goes for evolution theory, but for all the ‘pillars’ our contemporary world paradigm rests upon (germ theory, biomedical model, and all the other reductionist theories that have led to the multinational corporations dominating our world today). Ever wondered why the mainstream media hardly ever has anything negative to say about evolution theory, the biomedical model, vaccination, chemotherapy, etc.? Not realizing the extend as to how the public is being manipulated to accept all kinds of ‘scientific’ theories/models that are mainly good for business is truly an example of ignorance…
I’m sure there are lots of people who think that the earth is flat, that the moon is made of green cheese, and that storks bring babies. But all of those things are wrong, no matter how many people think them. Majority votes elect (some) governments, but they do not decide what is true. Similarly, your assertion that the media are corrupt and hiding the truth about chemotherapy is not founded in facts. That is probably why you don’t offer any evidence to support your ideas.
You do not say how the dna was formed. We now know that the dna strand is a language. A code. A single cell contains more information than a library of encyclopedias. Cells like bacteria. The 1st cells formed. No matter how many tries, how many times i throw a bunch of letters in the air, it isnt going to form an encyclopedia! It makes sense that an eternally present creator organized the dna code. And probably let things evolve from there.
Hi Rosemarie! Thanks for stopping by! I’m not sure how you got from not knowing how DNA forms to assuming the existence of God, but you might like to read how scientists think it happened on our page about RNA: https://quatr.us/biology/rna-cell-biology-evolution.htm. Of course you are free to believe that God created everything if you prefer.
You seem to just casually mention that ” But somehow some RNA or DNA molecules, or both, started hanging out in the water inside the bubbles of lipid membranes.” but the production of amino acids to proteins to DNA is not casual at all and to just try to assemble all of the improbable if not impossible events under the umbrella of “somehow” is just plain ridiculous .
•Think of DNA as the cell’s library, and RNA as a book that can be checked out of the library. A kind of RNA checks out information from the DNA to line up left handed amino acids in the exact order required for each individual protein.
•Next the correctly ordered left-handed amino acids are linked together by a “molecular machine.” This machine is made up of another kind of RNA working together with several specialized proteins. The machine links the properly ordered left-handed amino acids one to another to make proteins.
•Amino acids do not concentrate in the ocean; they disperse and break down.
•Amino acids will not link together in nature to form proteins; not even when scientists help them by buying all left-handed amino acids from a chemical supply house to make the perfect “organic soup.”
•If proteins could form, they could not get together with DNA because DNA does not form outside of living cells either.
If it were so easy to create living cells by just floating in the ocean while being protected by a lipid membrane then science would be able to have figured out how to duplicate the process by now and as far as I know, that has not happened.
Thank You for your time
If what you mean is that only God could have created life, then most scientists disagree with you. There are many seemingly easy things that today’s scientists can’t do yet. Science is still only just beginning to understand how life works – remember that only 150 years ago, many doctors still believed that bloodletting would cure illnesses. The ideas I present here may turn out to be wrong, of course, and then I will be happy to change my ideas. But this is the most convincing story we have right now.