At the End of the Book, Darwin wrote...
[quote=Darwin]"There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.”[/quote]
I'm not a biology expert so forgive my ignorance. I have a very simple question.
If evolution is true then why aren't new life-forms popping into existence? I purposely didn't use "evolve" because that requires a pre-existing life-form as in single-celled creatures evolved into complex multicellular life.
Perhaps biologists are in the dark about this. I haven't heard of any biologist who's theory of how life began has been proven. I've heard of the primordial soup theory and the gist of that theory is that random events lead to simple organic molecules and these evolved into cells and you know the rest of the story.
I find the present conditions of the world - liquid water, air, temperature - actually perfect for life to begin, start from scratch. Yet, we've never heard of scientists stating that they discovered a life-form has come into existence in the past 100 years.
Why is that?
I guess some would say that the available ecological niches are already filled to capacity leaving no room for new life-forms to come into existence, instead only existing life-forms evolve into new species.
I wonder if such an explanation suffices? Is there no vacant ecological real estate anymore?
I guess the 5 mass extinctions explain a lot. Each extinction was followed by repopulation of the biosphere by different kinds of organisms. The dinosaurs were followed by mammals for instance.
I'm just wondering if there are organisms that are actually coming into existence as we speak. Finding them would help us discover the secrets to life's origins.
I'm not a biology expert so forgive my ignorance. I have a very simple question.
If evolution is true then why aren't new life-forms popping into existence? I purposely didn't use "evolve" because that requires a pre-existing life-form as in single-celled creatures evolved into complex multicellular life.
Perhaps biologists are in the dark about this. I haven't heard of any biologist who's theory of how life began has been proven. I've heard of the primordial soup theory and the gist of that theory is that random events lead to simple organic molecules and these evolved into cells and you know the rest of the story.
I find the present conditions of the world - liquid water, air, temperature - actually perfect for life to begin, start from scratch. Yet, we've never heard of scientists stating that they discovered a life-form has come into existence in the past 100 years.
Why is that?
I guess some would say that the available ecological niches are already filled to capacity leaving no room for new life-forms to come into existence, instead only existing life-forms evolve into new species.
I wonder if such an explanation suffices? Is there no vacant ecological real estate anymore?
I guess the 5 mass extinctions explain a lot. Each extinction was followed by repopulation of the biosphere by different kinds of organisms. The dinosaurs were followed by mammals for instance.
I'm just wondering if there are organisms that are actually coming into existence as we speak. Finding them would help us discover the secrets to life's origins.
Comments (39)
"If evolution is true then why aren't new life-forms popping into existence?"
The 'forms' that Darwin speaks of are species and varieties of life, they are intra-vital forms, not one life form set against a different one. That said, there are 'kinds' of life, as might be gleaned from looking at a tree of life diagram, where you can find the three major 'domains' of life - bacteria, archea, and eukaryota - that come closest to being what you call 'forms of life':
As to why these three and not others, the answer largely has to do with various chemical, energetic, and environmental constraints (i.e. how various atoms and molecules bond, how energy is generated, stored, and expended, and where and how minerals and environmental processes are distributed in space and time) the study of which is very much still an active field.
That all said, the most promising theory has to do with deep sea vents, which provide a mineral rich, warm, and continually generating entropic processes for the formation of life.
We, of the endless forms most beautiful,
Are stunned that our glass to the brim is full,
Life’s wine coursing through us, as ‘magical’,
On this lovely, rolling sphere so bountiful.
Most of evolution is rather all too slow, even numbingly slow to us… for to be lucky enough to see a new species come about now, but, as you say, it happened and there is one tree of life of all the species (see the newer 'Cosmos' TV series).
The Earth at first wasn't much to speak of, as you indicate, with no plants, no oxygen, and nothing organic, but we can know that between then and now that life arose, so we have evolution surrounded.
For two billion years, bacteria created the atmosphere, by exuding oxygen that was useless to the, as a poison to them, really, and later plants did so, too.
Two chromosomes fused way back, giving 'us' 23 instead of 24; we could not longer mate with our old kind… https://www.bbvaopenmind.com/en/science/bioscience/the-origin-of-the-human-species-a-chromosome-fusion/
Are really saying this in our time of genetics and cross-breed hybrids? Or imply that humans haven't bred animals and plants? Or impacted the globe by transporting animals and plants to places they weren't found before?
My actual question is why are there no new life-forms coming into existence, especially since the conditions now would be "more" favorable then billions of years ago? We have liquid water, the sun's energy and organic substance literally everywhere.
I already posted my reason why this isn't the case which is that all ecological niches are filled to capacity.
Still, I was hoping for insights into other reasons why new life isn't developing on earth.
I guess, my mistaken "if" answers the question. No lebensraum, no new life.
Yes, new species in the biogenesis sense and not evolutionary sense.
Please read my replies above.
This makes no sense.
Oops. I meant abiogenesis
Wikipedia or me?
Ok. Thanks.
Note that the conditions of the Earth at the beginning of life were different from the present conditions.
Yes. Are the conditions now unfavorable?
Yes, extremely so. Because the planet is already full of life. Any new lifeform would have to compete with what's already present, and since the existing life has a massive headstart, any upstarts have no chance.
That's what I thought but could there be any other explanation?
Yeah I guess( too) bacteria aren't eager biologists trying to make a name for themselves. Isn't it odd that the conditions now are unfavorable to generate new life but favorable to sustain old life. I guess the reverse would be true a couple of billion years ago.
Depends how you look at it I guess. The conditions are unfavourable for building a new skyscraper on the site of the Empire State Building, but pretty good for sustaining the one that's there.
As far as I know, nothing has ever popped out of nothing. And even those who profess some quantum phenomena where particles wink in and out of existence, if their explanation is followed, it hints more of a rise and fall of vibration frequencies (to and from our range of perception) than instantaneous creation and annihilation.
There aren't new life-forms, only more advanced or better adapted life-forms which, gradually and eventually, manifest such distinct idiosyncratic characteristics that the relation to some progenitor is seemingly arbitrarily unlikely.
Still I don't get your reasoning. It's as if you have made up your mind that somehow the evolution of new species has stopped.
Speciation takes a long time. But nothing seems to show that it would be slowing down. As humans rapidly change the environment, evolution will naturally follow.
And to the idea that new species aren't coming up, just a brief internet search shows that this isn't so. Nylon eating bacteria surely have not been around since nylon was made only in 1935 and the bacteria were only found in 1975. Bacteria, plants and insects are the first that can change fairly 'quicly'. And as humans have changed the landscape so much, species that have adapted to the urban environment are the obvious choice for new species to come around (as cities haven't been around for long).
These are "evolved" creatures by which I mean old wine in a new bottle. Where are the brand new, so to speak, organisms that, forgive my limited vocabulary, pop into existence like, presumably, the very first single-celled organism that came into existence a couple of billion years ago?
https://www.sciencealert.com/darwin-s-finches-evolve-into-new-species-in-real-time-two-generations-galapagos
If you rather mean in the sense of abiogenesis, it wouldn't be easy to know that it's not regularly the case. It would be very simple, single-celled organisms, since that's how things get rolling. So in order to know that it's not regularly happening, you'd need to take samples of single-celled organisms and figure out a way to test their DNA/RNA that would rule out the possibility that they independently arose . . . but I'm not sure how we'd do that, because we have no way of knowing that it's necessarily the case that independently-arising DNA can't appear to be "familially" the same in different instances. (In order to really know that, we'd need many instances of independently arising single-celled organisms, where the fact that they arose independently is confirmed via some other means, where the evidence bears out that none of them appear connected to each other per their DNA/RNA)
Consider the following :
- Abiogenisis is probably a very rare event, which may or may not require conditions that are very different from the conditions now.
- The earth is relatively speaking pretty big for us to monitor in detail, the detail necessary to see microscopic little life. Futhermore, abiogenisis is hypothesized to have happened in deep sea near thermal vents, which is not a place we frequent all that often.
- When abiogenisis first happened on earth, there was no other life that could compete with new life. Now the earth is teeming with all kinds of life that allready went through a long proces of evolution, which could mean that new life is immediately eliminated if it were to pop into existence.
So it doesn't necessarily follow from the fact that we haven't seen new life, that there is no life popping into existence via abiogenisis now. It could very well be that it does still happen now, but that we just arent' there to see it.
Thanks for your inputs.
I think all basic blueprints of life came into existence at one single point in time (is it 3 billion years ago?). One blueprint or body plan becomes very successful and dominates. Then a mass extinction occurs and the dominant life-form is eliminated. Then the process restarts and since it's all random another body-plan becomes dominant and then another extinction and so and so forth. So, there really is nothing new in all of this. It's much like the Olympics - there are different champions every year but they're all human.
3.5 billion years ago, which is actually pretty fast after the earth became somewhat suited for life. Then it took a very long time to evolve multi cellular life. But by and large, yes, genetics show that life now can be traced back to the very first life... and lots of bottlenecks caused by extinctions-events and changes in circumstance (geology, climate and composition of atmosphere) got us where we are now.
So you aren't talking about evolution, but a repeat of abiogenesis: basically you are looking for a single cell organism to 'pop into existence' somewhere where there isn't life before. First problem is that we don't know exactly how it happened. Secondly, perhaps the places where abiogenesis happened have already life, which has made it a bit difficult to have that 'pristine state' where it would happen again...
That strikes me as the main reason new life doesn't come into being. If it takes 100s of millions of years for it to "evolve" from non-living matter, we would never see it "pop" into extence. Even the simplist life is incredibly complex. That leaves a very big door open for development to be disrupted by other life or changed conditions. Seems like it would take a very long period of stable conditions to life to develop abiotically.
We don't know how long it actually took to develop live from existing complex molecules, and i'm no biologist, but yes, that seems a plausible hypothesis.
Edit: I like that you put evolve in quotes there, because abiogenisis is not evolution. For evolution you need reproduction, and then you get a self-perpetuating proces. Molecules don't reproduce, so it seems to have been some random re-combination of complex molecules. And maybe this is a proces that doesn't built on itself (in that you have to start over each time)... And so it seems to be a chance event where a lot of time is not necessarily a prerequisite for it to happen (unlike say the evolution from a single cell to dinosaurs that does need a lot of generations). Say for example there is a 0,1% chance of that specific combination to happen given certain complex molecules, then it could happen anywhere between a day from now, a million years... or never, but the proces itself doesn't necessarily takes a lot of time.
:ok: Thanks
I used "evolve" on purpose, because it seems to me there is probably a lot of a sort of evolution going on before something reaches the point we might call it alive. It isn't just chemicals combining until a chance leads to life. There is a very complex non-biological process of self-organization that leads to chemical cycles and the development of what they call "nanomachines." See "Life's Rachet." Somebody here on the forum recommended it. Was it you @StreetlightX? Maybe it was @apokrisis.
See the Wikipedia link for nanomachines. The first animation shows one of the naturally occuring nanomachines that Hoffman described. A living cell is full of these and other processes going on at all times.
a) we do not have a list of all the species that now exist.
It's quite complete for mammals and birds, but even for them, a new mammal or bird is discovered sometimes (not very often). For all of the creatures with six, eight, and more legs, or no legs, we have a long but incomplete list. For single celled creatures we do not know how many we are missing. Probably a lot.
b) we do not know where de novo proto-living life would appear, and the surface of the earth has many immensely inaccessible places on it. New life forms could be arising in the bucket of slop on your back porch.
c) we do not know what they would look like, because they would be... new. And they would be very small, smaller than viruses.
d) be careful what you wish for. Several scary science fiction novels inform me that new life forms may not like us, and we may not like them, either.
If a new organism did develop completely independent of existing life, it seems to me it would be unlikely to be DNA based. There is also speculation that the genetic material in the earliest life might have been based on RNA or even some other organic compound. I guess it's also possible that a new species could develop from a virus or other source of DNA that might look like our current life.
'Tis a fantastic book, but yeah, it was Apo. The best current book for the lay reader is Nick Lane's The Vital Question. Super in depth look at cutting edge research into how life might have come about. A bit more technical than some other pop-science books, but its emphasis on energy constraints and the role it plays in the development of life - something alot of people don't think about - is super eye opening and worth the trudge.
Thanks. I'll take a look.
Thanks.