What stopped this evolution?

[The Barbarian]

A fundamental challenge to evolutionists. I don't think they can provide an answer, now and ever:

Why can't an eukaryotic cell evolve into a prokaryotic cell, or vice versa? Why is there such a clear cut boundary between the two?

Evidence shows it took around a billion years. So pretty difficult. The evidence shows it was by endosymbiosis. We still see that happening from time to time. Would you like me to show you?

A challenge on this issue to Christians: Why does God create these two different cells, so biologists call them two different 'kingdoms"?

God always seems to have used the simplest way to handle creation. Engineers have noticed that evolutionry processes are more efficient at solving very complex problems than design can do. They have started copying evolution to solve some of those problems. The process involves "genetic algorithms" that work by random mutation and natural selection. And they work very well. Would you like to see some examples?

 

[CoreyD]

Evidence shows it took around a billion years. So pretty difficult. The evidence shows it was by endosymbiosis. We still see that happening from time to time. Would you like me to show you?

I would, yes, thanks.

God always seems to have used the simplest way to handle creation. Engineers have noticed that evolutionry processes are more efficient at solving very complex problems than design can do. They have started copying evolution to solve some of those problems. The process involves "genetic algorithms" that work by random mutation and natural selection. And they work very well. Would you like to see some examples?

I would, yes, please.

 

[The Barbarian]

I would, yes, thanks.

Endosymbiosis:
Endosymbiotic theory is the unified and widely accepted theory of how organelles arose in organisms, differing prokaryotic organisms from eukaryotic organisms. In endosymbiotic theory, consistent with general evolutionary theory, all organisms arose from a single common ancestor. This ancestor probably resembled a bacteria, or prokaryote with a single strand of DNA surrounded by a plasma membrane. Throughout time, these bacteria diverged in form and function. Some bacteria acquired the ability to process energy from the environment in novel ways. Photosynthetic bacteria developed the pathways that enabled the production of sugar from sunlight. Other organisms developed novel ways to use this sugar is oxidative phosphorylation, which produced ATP from the breakdown of sugar with oxygen. ATP can then be used to supply energy to other reactions in the cell.


Both of these novel pathways led to organisms that could reproduce at a higher rate than standard bacteria. Other species, not being able to photosynthesis sugars or break them down through oxidative phosphorylation, decreased in abundance until they developed a novel adaptation of their own. The ability of endocytosis, or to capture other cells through the enfolding of the plasma membrane, is thought to have evolved around this time. These cells now had the ability to phagocytize, or eat, other cells. In some cells, the bacteria that were ingested were not eaten, but utilized. By providing the bacteria with the right conditions, the cells could benefit from their excessive production of sugar and ATP. One cell living inside of another is called endosymbiosis if both organisms benefit, hence the name of the theory. Endosymbiotic theory continues further, stating that genes can be transferred between the host and the symbiont throughout time.


This gives rise to the final part of endosymbiotic theory, which explains the variable DNA and double membranes found in various organelles in eukaryotes. While the majority of cell products start in the nucleus, the mitochondria and chloroplast make many of their own genetic products. The nucleus, chloroplasts, and mitochondria of cells all contain DNA of different types and are also surrounded by double membranes, while other organelles are surrounded by only one membrane. Endosymbiotic theory postulates that these membranes are the residual membranes from the ancestral bacterial endosymbiont. If a bacteria was engulfed via endocytosis, it would be surrounded by two membranes. The theory states that these membranes survived evolutionary time because each organism retained the maintenance of its membrane, even while losing other genes entirely or transferring them to the nucleus. Endosymbiotic theory is supported by a large body of evidence.
...
The most convincing evidence supporting endosymbiotic theory has been obtained relatively recently, with the invention of DNA sequencing. DNA sequencing allows us to directly compare two molecules of DNA, and look at their exact sequences of amino acids. Logically, if two organism share a sequence of DNA exactly, it is more likely that the sequence was inherited through common descent than the sequence arose independently. If two unrelated organisms need to complete the same function, the enzyme they evolve does not have to look the same or be from the same DNA to fill the same role. Thus, it is much more likely that organisms who share sequences of DNA inherited them from an ancestor who found them useful.


This can be seen when analyzing the mitochondrial DNA (mtDNA) and chloroplast DNA of different organisms. When compared to known bacteria, the mtDNA from a wide variety of organisms contains a number of sequences also found in Rickettsiaceae bacteria. Fitting with endosymbiotic theory, these bacteria are obligate intracellular parasites. This means they must live within a vesicle of an organism that engulfs them through endocytosis. Like bacterial DNA, mtDNA and the DNA in chloroplasts is circular. Eukaryotic DNA is typically linear. The only genes missing from the mtDNA and those of the bacteria are for nucleotide, lipid, and amino acid biosynthesis. An endosymbiotic organism would lose these functions over time, because they are provided for by the host cell.


Further analysis of the proteins, RNA and DNA left in organelles reveals that some of it is too hydrophobic to cross the external membrane of the organelle, meaning the gene could never get transferred to the nucleus, as the cell would have no way of importing certain hydrophobic proteins into the organelle. In fact, chloroplasts and mitochondria have their own genetic code, and their own ribosomes to produce proteins. These proteins are not exported from the mitochondria or chloroplasts, but are needed for their functions. The ribosomes of mitochondria and chloroplasts also resemble the smaller ribosomes of bacteria, and not the large eukaryotic ribosomes. This is more evidence that the DNA originated inside of the organelles, and is separate completely from the eukaryotic DNA. This is consistent with endosymbiotic theory.


Lastly, the position and structure of these organelles lends to the endosymbiotic theory. The mitochondria, chloroplasts, and nuclei of cells are all surrounded in double membranes. All three contain their DNA in the center of the cytoplasm, much like bacterial cells. Although less evidence exists linking the nucleus to any kind of extant species, both chloroplasts and mitochondria greatly resemble several species of intracellular bacteria, existing in much the same manner. The nucleus is thought to have arisen through enfolding of the cell membrane, as seen in the graphic above. Throughout the world, there are various endosymbiont bacteria, all of which live inside other organisms. Bacteria exist almost everywhere, from the soil to inside our gut. Many have found unique niches within the cells of other organisms, and this is the basis of endosymbiotic theory.

Endosymbiotic Theory - Definition and Evidence | Biology Dictionary

Endosymbiotic theory is the unified and widely accepted theory of how organelles arose in organisms, differing prokaryotic organisms from eukaryotic organisms.

biologydictionary.net

An observed case of evolution of endosymbiosis:
Korean Journal of Parasitology
2007 Mar; 45(1) 11–18

Natural occurrence of Mycobacterium as an endosymbiont of Acanthamoeba isolated from a contact lens storage case​

Recent in vitro studies have revealed that a certain Mycobacterium can survive and multiply within free-living amoebae. It is believed that protozoans function as host cells for the intracellular replication and evasion of Mycobacterium spp. under harmful conditions. In this study, we describe the isolation and characterization of a bacterium naturally observed within an amoeba isolate acquired from a contact lens storage case. The bacterium multiplied within Acanthamoeba, but exerted no cytopathic effects on the amoeba during a 6-year amoebic culture. Trasnmission electron microscopy showed that the bacteria were randomly distributed within the cytoplasm of trophozoites and cysts of Acanthamoeba. On the basis of the results of 18S rRNA gene analysis, the amoeba was identified as A. lugdunensis. A 16S rRNA gene analysis placed this bacterium within the genus Mycobacterium. The bacterium evidenced positive reactivity for acid-fast and fluorescent acid-fast stains. The bacterium was capable of growth on the Middlebrook 7H11-Mycobacterium-specific agar. The identification and characterization of bacterial endosymbionts of free-living protozoa bears significant implications for our understanding of the ecology and the identification of other atypical mycobacterial pathogens.

More examples here:

Bacterial endosymbiosis in amoebae - PubMed

The large, free-living amoebae are inherently phagocytic. They capture, ingest and digest microbes within their phagolysosomes, including those that survive in other cells. One exception is an unidentified strain of Gram-negative, rod-shaped bacteria that spontaneously infected the D strain of...

pubmed.ncbi.nlm.nih.gov

 

[The Barbarian]

Energy​

Volume 158, 1 September 2018, Pages 807-819

Optimization of automotive diesel engine calibration using genetic algorithm techniques​

...Random optimization methods along with surrogate models were firstly used to generate a population of engine calibrations, which then served as an initial population to a specifically conceived Genetic Algorithm (GA) based optimizer, which was finally applied on a real data set for a particular engine operating point. The results were compared with a calibration optimized using a traditional local approach method. A simultaneous reduction of about 20% in NOX and 1% in Brake Specific Fuel Consumption was achieved, with no significant increase in other emissions. The methodology described in the paper has the potential to reduce the calibration time and effort by half, while obtaining better calibrations.

 

[CoreyD]

Thanks @The Barbarian. I save it, and will read it when I have time.

 

[QvQ]

Why can't an eukaryotic cell evolve into a prokaryotic cell, or vice versa? Why is there such a clear cut boundary between the two

Interesting Question

 

[DamianWarS]

Absolutely not. If a plant could move, it would do much better than other plants.

plants do move. they respond to their environment and are capable of a lot of movements, functionally speaking their movement is motivated similarly to that of all animals, they just don't respond as quickly.

 

[The Barbarian]

Interesting Question

Why can't an eukaryotic cell evolve into a prokaryotic cell, or vice versa?

Because the evidence shows it didn't happen that way. It happened by endosymbiosis, the incorporation of other cells into a larger cell. Our mitochondria, for example still exist as genetically separate organisms, but neither they nor we can exist without each other. And yes, such endosymbiosis has been observed while it happened.

 

[The Barbarian]

plants do move. they respond to their environment and are capable of a lot of movements, functionally speaking their movement is motivated similarly to that of all animals, they just don't respond as quickly.

Well, usually...

 

[QvQ]

And yes, such endosymbiosis has been observed while it happened.

WHEN?
If endosymbiosis happened 1.5 billion years ago and over time those prokaryotes "evolved" into dinosaurs, then there are prokaryotes "evolving" today that will be dinosaurs 1.5 billion years from now?

If not, why not?

The question is about "system boundaries"

 

[The Barbarian]

And yes, such endosymbiosis has been observed while it happened.

WHEN?

1995

Bacterial endosymbiosis in amoebae - PubMed

The large, free-living amoebae are inherently phagocytic. They capture, ingest and digest microbes within their phagolysosomes, including those that survive in other cells. One exception is an unidentified strain of Gram-negative, rod-shaped bacteria that spontaneously infected the D strain of...

pubmed.ncbi.nlm.nih.gov

If endosymbiosis happened 1.5 billion years ago and over time those prokaryotes "evolved" into dinosaurs, then there are prokaryotes "evolving" today that will be dinosaurs 1.5 billion years from now?

No one can say. But while we often see parallel evolution (say in Australian marsupials and eutherians), we never see them become the same thing genetically. So unlikely.

If not, why not?

Probability. It would like two authors independently writing the exact same book.

The question is about "system boundaries"

One of my degrees is in systems with a focus on biological systems. I know I'd like to see that analysis. What do you have?

 

[FireDragon76]

I am not asking why can‘t a tree evolve into a dog. I am asking why can’t we have a moving (walking) tree (plant). Is movement a very very desirable function for survivorship? Can an eukaryote cell move?

Some plants actually do move. They just move very slowly, with a few exceptions. Plants can even communicate electrochemically.

Most single-celled life forms live as plantkon in the sea and move with ocean currents.

 

[FireDragon76]

Absolutely not. If a plant could move, it would do much better than other plants.

Not necessarily. The ability to move might come at the expense of other, more important traits, for instance. What's adaptive in one situation won't be in another one.

 

[FireDragon76]

Here's a cool TED talk on plant intelligence, and might be relevant to this discussion: