A team of researchers at Harvard University succeeded in creating a model of a primitive cell - a primary cell - capable of building, reproducing and containing DNA
The researchers referred in their study to the problem of the beginning of life on Earth. The common explanation today is that the initial genetic material - DNA or RNA - was preserved at the beginning of life in tiny fatty balls. These balls are called micelles and they are formed naturally when a fatty substance is mixed with water. The ancient micelles created a protective shell around the genetic material and saved it from environmental hazards.
Although this idea is widely accepted today, it fails to deal with the problem of the impermeability of the micelles. In order for the DNA and RNA molecules inside the cell to replicate and create additional copies of themselves, they need specific building blocks such as sugars and nucleotides. The fatty envelopes that surround the cells that exist today do not allow these building blocks to penetrate into the cell, but through special protein channels that pass through the membrane outside the cell and into it. Since it is very difficult to assume that these complex proteins existed during the formation of the first cells, this problem remains until now without a satisfactory solution.
The group of Jeff W. Szostek from Harvard Medical School decided to try and find a solution in a particularly creative way. The group started from the assumption that the molecular composition of the micelles at the time of the formation of cells - 3.5 billion years ago - was different from their composition today. There are many types of fatty acids, and the group tried to use different combinations of them to create micelles with different properties, through which simple sugars could penetrate and reach the interior of the primitive cell.
The researchers used ribose as a model sugar, and showed that it is able to penetrate through the micelle composed of a certain concentration of decanoic acid, decanol and glycerol monoester of decanoic acid - all fatty acids that exist in nature. At the same time, they came to know that the most common energy molecule in nature - ATP - is not able to penetrate effectively through the micelle. This result suggests that ATP had no role in the primary cells.
To prove the permeability of the micelles beyond any doubt, the researchers decided to create cells poor in the aforementioned fatty acids and test whether they are able to absorb nucleotides and incorporate them into their DNA. The researchers inserted into the micelles an efficient non-enzymatic replication mechanism capable of duplicating simple DNA strands. In doing so, they turned the micelles into, in effect, a model that might mimic the primordial cells on Earth. The micelles prevented the long strands of DNA from leaving the cell, but they allowed the nucleotides - the building blocks of DNA - to enter the cell, connect to the DNA and become part of the replication process of the genetic material.
"By showing that this can happen, and it does happen quite efficiently, we've gotten a little closer to our goal of creating a functional primary cell that can grow and divide on its own in the right environment," Szostek says.
The research provides new clues to the early life on Earth. While in the past researchers believed that the primary cells had to be autotrophs (that is, self-producers, producing energy from sunlight or from simple inorganic compounds), now it seems that the primary cells had to be heterotrophs (creatures that consume organic compounds from the environment ), because the metabolic products of the primary autotrophs could leak out of the cells according to the current model.
Although the two ideas that exist today - heterotrophs first and autotrophs first - encounter difficulties, the results of the study show that simple primary cells heterotrophs could be formed in a sterile environment rich in nutrients.
On the same subject
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The article on "Why there are homosexuals" was moved to the (new) website. You can find it by my name (for some reason a response with a URL is not received).
The discussion can be moved to responses to the article "Why are there homosexuals?"
https://www.hayadan.org.il/why-they-are-homosexuals-090603/
I'm in favor, super-interesting topic.
For Michael and Septem
I suggested to my father to publish an updated version of my article (not that there are any fundamental changes), then it would be possible to continue discussing closely to the substance of the matter.
Michael, I think you may be missing a bit.
Admittedly, there is almost no formal education on the subject, but in my imagination at least it is very possible that homosexuals also passed their genes on. Not only through relatives.
It is very possible that many of the homosexuals (as is also the case today, many of them gloamed about their inclination only after marriage and the birth of children) simply out of conformity or simply a simpler adherence to the norm, have produced children. "Fought" their urge.
This does not seem very unreasonable to me. I think you'll agree that this is a reasonable assumption. Especially in times when those who deviated from the norm could end up the same day as the dessert of their friends, or perhaps bait for wild boars.
After all, we know that societies not very far from us (from a few thousand years ago, and you probably know more about them than I do) have mostly adopted (to be honest, I'm not sure most of them. There may have been many such as Athens, I'd appreciate it if you correct me) quite homophobic policies.
Just because homosexuality is not expressed does not mean that it does not exist.
In any case, if I already mentioned earlier the matter of the "by-product" that Dawkins raises as a possible explanation for religion (as in the case of the moths); Perhaps through a similar by-product explanation it is possible to explain homosexuality (or at least a certain structure of the psychology of attraction that can explain homosexuality).
Food for thought.
lion:
Just don't get me wrong:
I am convinced that in humans the phenomenon is innate (but this does not require it to be genetic either) and I even tend to believe that it has genetic components.
My comments only concerned the validity of the arguments.
I just read the article.
The possibility that the tendency is transmitted by relatives exists, but the whole idea does not fit with the existence of homosexuality in a community where the individuals do not cooperate at all (and there are quite a few of these)
I haven't read the article yet, but I must say in advance that the arguments you raised seem illogical to me for the following reasons:
1. Homosexuality (at least until recently) could not be inherited by homosexuals because homosexuals did not have offspring (until recently - meaning - only a part of the period when we were homo sapiens)
2. Mongoloidism did not disappear either. It is indeed genetic, but not because of any advantage it gives to its carriers. Blindness, deafness, and other disabilities - they also do not give any advantage and are not tools from the world.
This does not mean that homosexuality is not genetic, but it also does not require that it be genetic.
I once read about some study (unfortunately I don't have a link to it) that showed that in a certain type of insect homosexuality can be induced by heating (!)
In view of the discussion regarding homosexuality that has developed here, I would like to refer to my article which explains that homosexuality is genetic and has an evolutionary advantage! (otherwise she would have become extinct).
http://www.hayadan.org.il/setter17.html
We may soon put an updated version on the (new) website.
Michael,
I must have not been precise enough. Thanks for the correction and the education.
Thank you Roy
Your explanation definitely changes the picture.
Wow, I forgot my initial astonishment at the good news because of the many answers!
We are slowly getting closer to biogenesis!
I hope I get to live and see a reconstruction of the beginning of life.
To the cool commenter:
In Desmond Morris's book "The Naked Monkey", it seems to me that in the chapter "Sex", Morris gives some pretty good reasons for the phenomenon of homosexuality in nature in general and in humans in particular.
In addition -
The alleged errors you mentioned are not exactly some feature that has been discovered. Dawkins suggests in his latest book "The God Delusion" to treat certain phenomena not as ascertained properties, but as side effects to ascertained properties.
For example, he suggests religious belief as a side effect that emerged as a result of children's trait of being "easy to believe." This feature is certainly important, for example, when children have to learn from the experience of adults. "Don't dip in the water of the river" is a suggestion that believing in it can save lives (in case the river is infested with crocodiles).
This is just an example, of course.
I am convinced that if we put some thought into the subject we will be able to bring up qualities that "suicide", for example, is a by-product of.
Although suicide is perhaps a bad example. This is because in order to explain something in an evolutionary way, it must first be widespread enough in the population for us to suspect that there is a strong and real genetic component to the matter.
However, it is possible that this element in the case of suicide is simply a trait or a number of psychological traits that we have developed in connection with other things. (So, it will be a byproduct).
Dawkins in the book gives a pretty good example (it also concerns suicide, just not in humans) in his latest book.
He cites as an example the moths that seem to kill themselves in a raging madness towards our electrifying lamps. can be asked; Why should they commit suicide?
However, as Dawkins explains, this suicide is nothing more than a byproduct of another feature of the moths that is usually essential and helpful (and the incidence of suicide as a result of it is infinitely small and insignificant compared to it).
After all, the moths are active at night. They have developed a mechanism that allows them to move in a straight line according to the angle at which the light rays from the moon and the stars hit their eyeballs (in many types of insects, the eyes are made up of many eyeballs that "connect" together). The mechanism, of course, is based on the fact that the light source is at an infinite distance (after all, this is the distance of the moon or the stars in front of the moth).
The suicide of the moths is nothing more than a by-product of another, often effective, feature of the moths.
Hope I gave you food for thought.
It seems to me that the bonobo monkeys can be added to the list of monkeys that also have homosexual relationships.
Roy:
You're wrong.
I tried to paste a link from Wikipedia here, but for some reason the comment is not received, so I try text without a link.
Look for the entry Homosexuality in Wikipedia and under it go to the chapter Homosexual behavior in animals
Roy:
http://en.wikipedia.org/wiki/Homosexuality#Homosexual_behavior_in_animals
Avi:
Homosexual relationships actually do exist in animals.
You yourself mentioned the pygmy chimpanzees but not only them.
I even read once that there is a type of fly - I don't remember at the moment which one (although almost everything is done with Drosophila) for which they showed that what determines the sexual orientation (and not the species!) is the temperature at which it is grown (which shows that, at least for this fly, it is not a genetic tendency ).
By the way, at this moment I decided to search on Wikipedia and this is what I found:
http://en.wikipedia.org/wiki/Homosexuality#Homosexual_behavior_in_animals
Michael,
A small and marginal correction: to the best of my knowledge, homosexuality in the vast majority of animals does not amount to actual sexual relations. It is interpreted as the weak male's way of showing his respect for the ruler. The weak man exposes his bottom to the ruler, who may loom over him, but without any real penetration, but simply for the sake of showing superiority.
The only animal I know of that has homosexual relations for pleasure is the pygmy chimpanzee.
To the cool commenter:
The questions you raised are actually among the best proofs that this is an unintentional evolution and not a product created by some intentional hand.
The flexibility to create changes is part of the basis of the evolution phenomenon and since the changes are random - not all of them are beneficial.
It is not known if a phenomenon like homosexuality has a genetic origin, but whatever the origin may be - natural selection does not encourage it. This is a phenomenon that exists among most animals, so it is difficult to define it as a result of our developed mind.
What can indeed be a consequence of our minds are phenomena such as abstinence from sex on some religious or ideological background.
Evolution chooses traits according to their contribution usually and not according to their individual consequences which in certain circumstances can be harmful, so it is possible that the phenomenon of abstinence is a price that the human race pays for having a brain and a brain, as we know, can also be enslaved to all kinds of superstitions.
But I repeat - the "bugs" are the best witnesses to the randomness of the process. Notice how the Iroquois squirm when you compare them with the wings of the ostrich - wings that are completely unable to fly: what intelligent or divine planner would bother to plan such nonsense?
reagent,
It's not related to the article, but I'll try to answer anyway.
First of all, it is very difficult to define us as a species 'considered best in its own mind'. Our brain is good at putting thoughts into words and tools, but there is no reason why it would not be equally good in other areas. It is very possible that he has his little bugs - depression, phobias, etc. In fact, it is possible that some of the advantages of our brain - its ability to imagine situations, its creativity, etc. - are also expressed in the disadvantages you described. As long as the number of individuals in the population in which these 'deviations' appear is small compared to the entire population, the species can continue to survive.
In general, in the last tens of thousands of years man developed tools (fire, wooden and stone tools) that allowed him to prosper and expand the size of the population to a great extent. In such a situation, even such small bugs in a large population will not stop the growth.
By the way, when I look at the majority of the population today, I see people who want to raise children, love them, want to have sex and are not gay/lesbian. All this in the most permissive environment that has ever existed, where people can also not have children if they want to. So apparently these urges are embedded in us very deeply as a result of evolution.
A question about evolution.
If the theory of evolution is true (which I assume it is) then how is it that there are humans (a species that is considered the best in its brain) with basic evolutionary errors such as: people who commit suicide (a large part of them even before they lost their virginity), people who don't like children, people who don't Want to raise children, people who don't want to have sex (for example those who lead celibacy/nuns), homosexuals (of both sexes).
Each of those above should not benefit from continuing his genetic lineage..
Friends, please. Let's maintain a basic attitude of respect for each other.
Gillian,
This is a very basic model of cells that don't even deserve to be called cells. If such cells ever existed, it was over 3.5 billion years ago. The researchers did not try to produce an artificial cell but to test whether the hypothesis of their model works.
Gillian:
Oh! Someone thought you were a guy again! Let's see how you react this time!
The intention here is that they will produce only the cell and not the DNA, but if you read my first response you will understand that the continuation that will lead to a complete living cell is quite clear.
There is currently a project to create DNA synthetically by completely chemical means.
Search for information on mycoplasma labortorium and you will understand what I am talking about.
What are you afraid of Gillian?
When they make a full artificial cell and you have nothing to load, what then? kill yourself
Quote from the article: "The researchers inserted into the micelles an efficient non-enzymatic replication mechanism capable of duplicating simple DNA strands."
From this I understand that some existing DNA was used, correct me if I'm wrong - and if that's the case, where is the artificial cell here?
The research itself is very interesting and may lead to the future development of completely artificial microorganisms - which is what I think they have done here. Regarding the current study, the starting point of the researchers is more interesting.
What if their basic assumptions are wrong? Since they start from the premise that ancient micelles were different from the current ones, they had to start applying other mechanisms to the "cells" they created in the laboratory. As the experiment developed, they had to look for different mechanisms in order to "activate" the current cell. The problem is, the researchers threw the current results, on what really supposedly happened in the development of life on Earth. Since they started from a certain point of assumption that led to the need to change other points of assumption, the chances that they built a new model and do not describe an existing model are very high.
This experiment reminds me of a story that Odette once told: after publishing a recipe for a cake, Odette received a letter from an enthusiastic fan who wrote to her: I replaced the flour in the original recipe with cornflour, the sugar with jam, the eggs with oil (because the grocery store was closed) and the chocolate with nuts - your cake turned out amazing !!!!
In conclusion: I would not be so quick to throw this development on the possibility that this is what really happened in the ancient cells. There are too many factors introduced here in order to adapt these cells to a certain model and I don't find many reasons why to assume that this was also the ancient real model, except for a logical idea that might turn out to be the creation of the first artificial life IN VITRO but not necessarily what happened in nature...
Hanan Sabat
http://WWW.EURA.ORG.IL
I wonder what will happen if Craig Venture now takes the synthetic DNA he produces and implants it in such cells housed in a nourishing environment: we may really get synthetic life in the full sense of the word!