If eukaryotic cells can survive in extreme conditions, then why are their still prokaryotic organisms?

  • $\begingroup$ This is essentially the same as another question that was just submitted - have you tried looking at some textbooks? $\endgroup$ – Vance L Albaugh Feb 7 '16 at 15:41
  • $\begingroup$ The question suggests that you might want to have a look at Understanding Evolution (UC Berkeley), a free online introductory course to evolutionary biology. $\endgroup$ – Remi.b Feb 7 '16 at 19:34
  • $\begingroup$ I am not quite sure I understand the relationship between the title and the content of the post. Also, I suppose you meant "evolved" rather than "developed". $\endgroup$ – Remi.b Feb 7 '16 at 19:44
  • $\begingroup$ Are you thinking that eukaryotes are so competitive that it seems weird to you that procaryotes would not be outcompeted and get extinct. Do I understand you correctly? $\endgroup$ – Remi.b Feb 7 '16 at 19:48
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    $\begingroup$ It is like asking if humans are so advanced, then why do gorillas exist. Basically, all lifeforms are different survival strategies and none is "better" than the other (whatever exists is good enough for this environment). Please go through the website that Remi mentioned. It explains the evolution basics nicely and in easy words which even a high-schooler can understand. If you have specific doubts related to evolution then please feel free to ask (but make an effort from your side before asking others). I let your other question be but I have to put this on hold. $\endgroup$ – WYSIWYG Feb 8 '16 at 5:17

As far as I understand your question, the "development" of eukaryotic cells can be linked to the endosymbiotic theory Symbiogenesis.

This diagram only depicts a possible trajectory of evolution which is still unknown.

this diagram depicts a **possible** trajectory of evolution which is still unknown

  1. A cell that respired anaerobically took in a bacterium that respired aerobically, supplying both itself and the larger cell with energy in the form ATP. This created a competitive advantage for the larger cell because aerobic respiration is known to be more efficient than anaerobic respiration. Unhurriedly, the aerobic bacteria evolved into mitochondria and the larger cell into a heterotrophic eukaryote.
  2. A heterotrophic cell took in a smaller photosynthetic bacterium, which supplied it with organic compounds, thus making it an autotroph. The photosynthetic prokaryote evolved into chloroplasts and the larger cell into photosynthetic eukaryotes.
  • $\begingroup$ Do we know which aerobic bacteria evolved into mitochondria? Do they still exist? $\endgroup$ – Count Iblis Feb 8 '16 at 0:56
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    $\begingroup$ @CountIblis Ancestors of mitochondria belong the the group of α-proteobacteria. Many free-living bacteria of this clade still exist. $\endgroup$ – WYSIWYG Feb 8 '16 at 5:52

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