Why don't we evolve into microbes?

  • Thread starter Yashbhatt
  • Start date
In summary, the conversation discusses the concept of "Survival of the Fittest" by natural selection and questions why other animals, including humans, do not evolve into microbes in order to better survive in extreme conditions. It is explained that evolution does not have a plan and organisms with traits that increase their fitness are more likely to survive and reproduce. The conversation also addresses the idea of genes playing a role in evolution and how mutations can be both positive and negative. It is noted that intelligence has a survival value in evolution.
  • #1
Yashbhatt
348
13
We are aware of the term "Survival Of The Fittest by Natural Selection". An organism evolves so that it can survive in its prevailing environment. We know that some microbes are capable of living in the most extreme conditions. Viruses in act can kind of switch between living and non-living. So, why don't other animals including humans evolve into microbes so that we can survive better? Why does the arrow of evolution always point in the direction of complexity? Is it because humans are not exposed to extreme conditions?
 
Biology news on Phys.org
  • #2
Evolution doesn't have a plan. "Let's see. In 500,000 generations my offspring will need to see or they'll be gobbled up by predators that can see. I better start working on those eye things!" Evolution doesn't work that way. Evolution is a local optimization function. The organisms that produce offspring win. Those that don't lose.
 
  • #3
But eventually mutations should help organisms to survive better and humans have advanced so much that instead of adjusting our environment, we try to adjust environment to suit our needs. So, someday we may think, "Hey, being a microbe is cool and helps us survive. ".
 
  • #4
Yashbhatt said:
Why does the arrow of evolution always point in the direction of complexity?

It doesn't.

Some of todays marine filter feeders were in the past freely roaming animals, but later became sessile. Some of the lizards lost their legs to become snakes. Some of the birds lost the ability to fly, same happened to some species of insects inhabiting remote islands. Given the chance of inhabiting a safe niche at the price of losing a costly trait, evolution will choose the former.

"Survival of the fittest" is a tricky term. If "the fittest" means "the one best suited to surviving and reproducing", it is IMHO acceptable (although still doesn't cover all evolutionary processes). If "the fittest" is assumed to mean "the fastest, the strongest" - it is easily ridiculed by counterexamples.
 
  • #5
Thanks Borek. I was unaware of organisms becoming less complex.

If any organisms of a certain species are exposed to extreme conditions, then is it possible for them to evolve into microbes?
 
  • #6
Yashbhatt said:
If any organisms of a certain species are exposed to extreme conditions, then is it possible for them to evolve into microbes?
By that I assume you mean a complex organism? The answer is no. They die. Or grow thicker fur. Or lose their fur.

There is no evolutionary path from human back to microbe.
 
  • #7
D H said:
There is no evolutionary path from human back to microbe.

But doesn't it seem absurd. Microbes can survive in the harshest of environments. Then, what was the need to evolve into complex organisms?
 
  • #8
Yashbhatt said:
But doesn't it seem absurd. Microbes can survive in the harshest of environments. Then, what was the need to evolve into complex organisms?

What do you think might be the evolutionary path from human to microbe? THAT seems absurd.
 
  • #9
phinds said:
What do you think might be the evolutionary path from human to microbe? THAT seems absurd.

I don't mean to say that we should evolve into microbes as I said in the original post. I agree that evolution doesn't have a plan. But evolution should help organisms survive better. So, why not be a virus? Live when you want, become inactive, live again.

But I am not sure about it. do our genes help us evolve directly to the type which suits our environment or do they generate just some random mutations and some of them survive while others die?
 
  • #10
Yashbhatt said:
But I am not sure about it. do our genes help us evolve directly to the type which suits our environment or do they generate just some random mutations and some of them survive while others die?

Yes, random Gene mutations and environment drives evolution. So let's say a human has a mutation that gives him/her a trait that increases their fitness. They now have a higher chance of survival than those with less fitness and so will have a higher chance to reproduce, and thus, passing on his/her's genes. Over time, this trait may be in most of the population (a change in allele frequency of a certain gene, which is evolution in terms of genes).

Again, if suddenly the environment became hostile to humans, but inhabitable by microbes, then humans would simply die out. Evolution can't say, "Alright, humans are dieing. Time to evolve them to suit the environment by changing them into microbes by giving them a certain gene mutation here and there."
 
Last edited:
  • #11
But if the mutations are random, then how come every organism of the same species evolves nearly in the same way? Does one gene of a member say to another of another member : "Hey, this mutation among the random one works. I rate it 5 stars. You should try it!"?
 
  • #12
Yashbhatt said:
But if the mutations are random, then how come every organism of the same species evolves nearly in the same way? Does one gene of a member say to another of another member : "Hey, this mutation among the random one works. I rate it 5 stars. You should try it!"?

Remember, not all mutations are good. In fact, most mutations are negative. For example, Sickle-cell disease, a genetic disorder, is caused because the people with te disease their hemoglobin gene allele differs by just a little from the normal allele. So negative mutations cause the organism to have a lower fitness and in turn lower chance of survival. So those with less fitness will generally have lower chance to create offspring and those with higher fitness will have a higher chance of surviving.

However, in this day and age, even those (humans) with lower fitness can survive due to technology advances.

It's not that genes are telling each other who is better, it's just that genes that give positive traits will give an organism an advantage in survival and so those without the advantage have a lower chance to create offspring. The same applies to genes that express negative traits.
 
Last edited:
  • #13
There is obviously a bias towards intelligence because it has survival value. Smart critters figure out more efficient ways to kill and eat dumb critters. When dumb critters start to lose the survival race, smart critters figure out how to farm them.
 
  • #14
Chronos said:
There is obviously a bias towards intelligence because it has survival value. Smart critters figure out more efficient ways to kill and eat dumb critters. When dumb critters start to lose the survival race, smart critters figure out how to farm them.

lol farming. Reminds me of the milk industry... :(
 
  • #15
Yashbhatt said:
But if the mutations are random, then how come every organism of the same species evolves nearly in the same way? Does one gene of a member say to another of another member : "Hey, this mutation among the random one works. I rate it 5 stars. You should try it!"?

You don't understand how it works. It is not separate organisms that evolve, it is a population that evolves. Basically mutation occurs once, then it either spreads in the population in the future generations, or not.
 
  • #16
@ Borek But isn't that very unlikely. How come all members of a generation have the same mutations when those mutations are random?
 
  • #17
Yashbhatt said:
How come all members of a generation have the same mutations when those mutations are random?

They don't all have the same mutation. Chances are progeny of a member with a particular mutation all have the same mutation. If it is beneficial, they will start to dominate the population in the next generations.

Say, someone has a mutation that makes them twice as intelligent as others. Chances are, their kids will have this mutation as well. If it is beneficial (looking around I doubt, but let's say it is), after several generations their grandgrandkids will be more numerous than kids of their contemporaries, and they will dominate the population.
 
  • #18
Who decides if it is beneficial or not?
 
  • #19
Generally speaking - environment.

Note that "environment" doesn't have to be understood in terms of just geography and ecosystem, just like "the fittest" doesn't necessarily mean "the fastest, the strongest". Environment means also other members of your population.

Also note that it is not that someone "decides". Who "decides" that giraffe can eat leaves from the high trees? Who "decides" that zebra mussel is much more effective at surviving and reproducing in the lakes than many other bivalve species? Who "decided" whether a deer run out or was captured by a tiger? Nobody "decides", it either happens, or not.

There is more to it, but you should have the basic things straight first.
 
  • #20
Borek said:
There is more to it, but you should have the basic things straight first.

A lot of people tell me this.

Thanks for the help. I have one more question: Is there any possibility of acquired characteristics being seen in the next generation?
 
  • #21
Yashbhatt said:
Is there any possibility of acquired characteristics being seen in the next generation?

In the context of the evolution and genetics - no.

But in general it depends on what do you mean by acquired and what ways of transmission do you consider. Just because someone trained their biceps doesn't mean their children will have huge biceps as well. But if someone learned hunting they can pass this ability by teaching their kids. I guess that's not what you were thinking about when asking the question, but sometimes the division line between things passed through genetics and through teaching is quite hard to draw.
 
  • #22
Yashbhatt said:
Is there any possibility of acquired characteristics being seen in the next generation?
Simple Answer: No.

Slightly More Complicated Answer: No. When Darwin wrote On The Origin of Species he did not entirely understand the full mechanisms involved in evolution. At times he suspected that some characteristics developed by individuals might be carried forward in some way to the next generation. This was a concept that had been proposed earlier by Lamark. His uncertainty in this regard is apparent in changes made to Origin in the different editions.

By the time Darwin's underlying thesis had been combined with the concepts of population genetics in the Modern Synthesis, inheritance of acquired characteristics was dead and buried.

More Complete, Current Answer:Certain environmental changes that do not directly change the DNA of an individual can, however, produce heritable changes that extend through a number of generations. This is the subject of the field of epigenetics. However, that is not a "full blooded" inheritance of an acquired characteristic, simply the on-going expression - through generations - of a reaction to an environmental impact.
 
  • #23
But don't we see children of actors having good acting ability or of singers having good voice?
 
  • #24
Acting ability likely arises through a combination of inherited and environmental factors. I suspect the proportion involved varies in each individual case.

It is not uncommon for children to wish to pursue the profession of one or other parent, or to be guided (or forced) in this direction by parents. Moreover successful actors have the contacts that help their children get access to opportunities other lack.

I suspect singing has a much stronger genetic component, related to various aspects of physiology. Therefore it is not surprising that a good singer, who has the genetic coding that gives them the physiology for good singing, would have children who inherited these same genes and thus the ability to be a good singer.

So, none of this is surprising and is wholly consistent with my Simple Answer given above. i.e. we do not inherit acquired characteristics.
 
  • #25
And that "singing gene" is a result of random mutations?
 
  • #26
Yashbhatt said:
And that "singing gene" is a result of random mutations?

Voice has to do with vocal cords, mouth size, breathing, etc. So people with higher pitch voices who can go higher have genes that work in favor of singing. Those with these genes just happen to survive and pass their genes down. So singers who have these genes that favor singing pass it down to their children.

So yes, the random gene mutations that gave bigger/smaller vocal cords survived and those who have these genes may have the potential to sing clearer, at a higher pitch, etc.
 
Last edited:
  • #27
Yashbhatt said:
But don't we see children of actors having good acting ability or of singers having good voice?

There could be a completely different explanation.

Suppose that "acting" or "singing" doesn't require any special talents at all. Anybody can do it, but there is only work for a small number of actors and singers, so most people choose a different career. If you try to become a professional actor or singer, you need to get lucky to find work.

In that case, it should be obvious that children of actors or singers will have more chance of "getting lucky" than the rest of the population, because of the people their parents know.

I'm not saying that hypothesis is true, but if you want to claim that acting and singing ability is inherited, you need to show that it is false!

Actually there is some empirical evidence that no "special ability" is required for western classical music, beyond having the opportunity to learn. For example see http://en.wikipedia.org/wiki/El_Sistema. But that reference is far too US-centered - it ignores similar projects in the Middle East, South Africa, etc, and the huge growth of western music performance in China (for example the Pearl River Piano Company is the largest piano manufacturer in the world, and the number of piano students in China is estimated at between 30 and 80 million).
 
Last edited:
  • #28
ecoo said:
Voice has to do with vocal cords, mouth size, breathing, etc. So people with higher pitch voices who can go higher have genes that work in favor of singing. Those with these genes just happen to survive and pass their genes down. So singers who have these genes that favor singing pass it down to their children.

So yes, the random gene mutations that gave bigger/smaller vocal cords survived and those who have these genes may have the potential to sing clearer, at a higher pitch, etc.

Why did those mutations survive? Singing does not help in adapting to the environment.
 
  • #29
Yashbhatt said:
Why did those mutations survive? Singing does not help in adapting to the environment.

Could be just luck, since the mutations don't exactly decrease fitness nor increase it.

However, let's not forget that a 'nice" voice is relative (e.g. low or high pitch, thin or vibrant). So there isn't set traits that make a voice sound better. However, say that men generally like girls with higher pitched voices. Then those girls with a higher pitched voice have an evolutionary advantage over those with a lower pitched voice (men are attracted to higher pitch and have a higher chance to reproduce with the girls with high pitch). Later in the path of time, suddenly most girls in the general population have a higher pitched voice.
 
Last edited:
  • #30
Yashbhatt said:
Why did those mutations survive? Singing does not help in adapting to the environment.

Not everything you are capable of doing necessarily provides better adaptation to your environment.

The ability to sing well may just reflect an individual with superior control of the muscles involved in speech (and consequently breathing). So to for the musician, these are individuals who exhibit superior hand-eye coordination, or control of the muscles involved in breathing. These are characteristics which also might enable an individual a better chance at survival, other things being equal, but because we don't have to wrestle our breakfast away from a cheetah every morning, we can use these qualities for other pursuits.
 
  • #31
Yashbhatt said:
Why did those mutations survive? Singing does not help in adapting to the environment.
Really? You don't think the winner of Pop Idol, or the X-Factor lack success in finding mates?
 
  • #32
Yashbhatt said:
Why did those mutations survive? Singing does not help in adapting to the environment.


You're only considering natural selection but sexual selection is a powerful force for evolution too. If a trait enhances an organisms ability to reproduce then it will pass on it's genes more than others. There's no "singing" gene but the combination of genes that give one a propensity to sing well could make it easier for an individual to reproduce. A real world example of this would be birds, some of which have evolved very complex mating calls.

As for why humans don't evolve into bacteria: it's possible there is a very, very long series of adaptations that lead to that but each individual stage would have to confer a selective advantage. This is unlikely.
 
  • #33
Okay okay I get it now.
 
  • #34
Usually, organisms don't evolve into a niche where there is already plenty of competition. Microbes have held their niche for about 3.5 billion years already, so they seem adapted well enough to compete with just about anything that comes along, with much disadvantage to the newcomer.

After all, humans have tried to exterminate/eliminate disease carrying microbes actively for a little over a century now. We won some impressive early victories with the development of artificial antibiotics (like penicillin, et seq.), but now the pendulum is swinging back into the microbes' favor since the microbes which survived the antibiotic onslaught have produced antibiotic-resistant strains which are rendering our medical arsenals pitifully ineffective. Having large scale outbreaks of infections return is not an exciting prospect for humanity, especially those in the developed world who have grown accustomed to antibiotic treatment providing quick and effective cures for such illnesses.
 
  • #35
SteamKing said:
Usually, organisms don't evolve into a niche where there is already plenty of competition. Microbes have held their niche for about 3.5 billion years already, so they seem adapted well enough to compete with just about anything that comes along, with much disadvantage to the newcomer.

After all, humans have tried to exterminate/eliminate disease carrying microbes actively for a little over a century now. We won some impressive early victories with the development of artificial antibiotics (like penicillin, et seq.), but now the pendulum is swinging back into the microbes' favor since the microbes which survived the antibiotic onslaught have produced antibiotic-resistant strains which are rendering our medical arsenals pitifully ineffective. Having large scale outbreaks of infections return is not an exciting prospect for humanity, especially those in the developed world who have grown accustomed to antibiotic treatment providing quick and effective cures for such illnesses.

That is the reason I thought that being a microbe is better as one can adapt very quickly to the environment. (For example, the common cold virus).
 
<h2>1. Why don't humans evolve into microbes?</h2><p>Evolution is driven by natural selection, which favors traits that increase an organism's chances of survival and reproduction. Microbes and humans have vastly different environments and lifestyles, so there is no selective pressure for humans to evolve into microbes.</p><h2>2. Can humans evolve into microbes in the future?</h2><p>Evolution is a gradual process that occurs over many generations. It is unlikely that humans will evolve into microbes in the future as there is no selective pressure for this to happen. Additionally, humans have already evolved into a highly complex and specialized species, making it difficult for such a drastic change to occur.</p><h2>3. What is the difference between humans and microbes that prevents us from evolving into them?</h2><p>Humans and microbes have vastly different genetic makeup and cellular structures. These differences are a result of millions of years of divergent evolution and make it unlikely for humans to evolve into microbes. Additionally, humans and microbes occupy different ecological niches, which also contributes to their distinct evolutionary paths.</p><h2>4. Do other animals evolve into microbes?</h2><p>Microbes are a diverse group of organisms that have evolved to occupy nearly every ecological niche on Earth. However, there is no evidence to suggest that other animals are evolving into microbes. Evolution is a unique and unpredictable process, and it is unlikely for two species to follow the exact same evolutionary path.</p><h2>5. Could humans evolve into a different type of microbe?</h2><p>While it is highly unlikely for humans to evolve into microbes, it is possible for humans to evolve into different types of microbes. This could occur through genetic mutations and natural selection, but it would require significant changes in the human genome and environment. However, there is no evidence to suggest that this is currently happening or will happen in the near future.</p>

1. Why don't humans evolve into microbes?

Evolution is driven by natural selection, which favors traits that increase an organism's chances of survival and reproduction. Microbes and humans have vastly different environments and lifestyles, so there is no selective pressure for humans to evolve into microbes.

2. Can humans evolve into microbes in the future?

Evolution is a gradual process that occurs over many generations. It is unlikely that humans will evolve into microbes in the future as there is no selective pressure for this to happen. Additionally, humans have already evolved into a highly complex and specialized species, making it difficult for such a drastic change to occur.

3. What is the difference between humans and microbes that prevents us from evolving into them?

Humans and microbes have vastly different genetic makeup and cellular structures. These differences are a result of millions of years of divergent evolution and make it unlikely for humans to evolve into microbes. Additionally, humans and microbes occupy different ecological niches, which also contributes to their distinct evolutionary paths.

4. Do other animals evolve into microbes?

Microbes are a diverse group of organisms that have evolved to occupy nearly every ecological niche on Earth. However, there is no evidence to suggest that other animals are evolving into microbes. Evolution is a unique and unpredictable process, and it is unlikely for two species to follow the exact same evolutionary path.

5. Could humans evolve into a different type of microbe?

While it is highly unlikely for humans to evolve into microbes, it is possible for humans to evolve into different types of microbes. This could occur through genetic mutations and natural selection, but it would require significant changes in the human genome and environment. However, there is no evidence to suggest that this is currently happening or will happen in the near future.

Similar threads

Replies
6
Views
3K
  • Biology and Medical
Replies
5
Views
958
Replies
3
Views
4K
  • Biology and Medical
Replies
15
Views
1K
Replies
10
Views
2K
Replies
17
Views
3K
  • Biology and Medical
Replies
15
Views
2K
  • Biology and Medical
Replies
7
Views
1K
Replies
20
Views
2K
  • Biology and Medical
Replies
7
Views
1K
Back
Top