Did cells acquire organelles such as mitochondria by gobbling up other cells?
(Or, can the endosymbiont theory explain the origin of eukaryotic cells?)
by Dr Don Batten, CMI–Australia
6 July 2000
Eukaryotic cells, such as yeast and those of animals and plants, have a membrane-bound
nucleus, chromosome structures and organelles such as mitochondria and chloroplasts,
whereas prokaryotic cells, such as bacteria, lack these features. Many evolutionists
believe Lynn Margulis’ idea that eukaryotic cells came about as a prokaryotic
cell ‘ate’ (by a process called endocytosis) other prokaryotic cells,
which then became the mitochondria and chloroplasts. The engulfed cells supposedly
reproduced in step with the host cell in some sort of symbiosis (mutual advantage),
just by chance, before coming under the control of the primitive eukaryotic cell
(which developed chromosome structures, nuclear membrane, Golgi apparatus, etc,
etc, also). Over time, portions of the mitochondrial and chloroplast genomes happened
to transfer to the nucleus.
Problems abound with this scenario. For example, how could the enveloped cells reproduce
in close synchronicity? How did lateral gene transfer into the nucleus take place
when the nuclear membrane is designed for the passage of mRNA (out), and to contain
DNA? If DNA were passed between the engulfed cell and the host cell, would not the
host respond by degrading the foreign DNA, because it would detect it as a virus?
(Note that the enzymes used so widely to chop up DNA into pieces in DNA sequencing
studies come from bacteria, i.e. prokaryotes—they function in destroying foreign
DNA inside the bacteria.)
It is only to be expected that there would be similarities in many of the genes
for photosynthesis or respiration between prokaryotes and eukaryotes—they
have to achieve the same chemistry (photosynthesis: light energy + carbon dioxide
+ water giving glucose plus oxygen. Respiration: glucose (C6H1206)
giving CO2 + H20 + energy). Furthermore, they have the same
Designer! For an in depth treatment of the concept that God designed things in a
way to reveal himself and thwart naturalistic explanations of origins, see The Biotic Message (right).
However, detailed studies of the DNA base sequences have shown that the pattern
of similarity between eukaryote and prokaryote is not what would be expected from
the endosymbiont hypothesis. Doolittle said,
‘Many eukaryotic genes turn out to be unlike those of any known archaea or
bacteria; they seem to have come from nowhere.’ (Doolittle, D.F., Uprooting
the tree of life, Scientific American 282(2):72–77,
2000.).
The endosymbiont idea was severely dealt with in the 70s and early 80s, and should
have died. But, what else is there for the evolutionist? It is very much akin to
chemical evolution—anyone who knows a little of the biochemistry involved
in the most basic of bacteria knows that formation of a living cell from chance
chemical reactions, even in highly controlled/contrived Miller-type experiments,
is absolutely impossible. But that it happened is deemed to be certain (well, we
have living cells, don’t we?!) and it is taught that way in universities around
the world. For a thorough refutation of the idea that life could form by natural
processes, see the Origin of life articles.
However, something like this must have happened, because we have plants,
for example, which are fantastically complex things and they must have
arisen from some stepwise evolutionary process (Did I just hear someone say they
think the cells were created? Now listen here, that’s religion, which has
nothing to do with the real world of cells and science. Science is about material
explanations, and just you remember that! We just will not accept an intelligent
cause, regardless of whether the evidence supports it!). See
Lewontin’s admission regarding the materialistic bias applied in much
scientific reasoning today about origins.
Note that this view that science can only deal with materialistic answers is a modern
misuse of science. The founders of modern science did not see things that way (Newton,
Kepler, Boyle, Faraday, Pasteur, Kelvin, Pascal, etc.)—see Creation scientists. There are many modern highly qualified
scientists who believe Genesis literally—see In Six Days: Why 50 [Ph.D.] Scientists Choose to Believe in Creation.
Read online.
And science does deal with non-observable, intelligent causes where it suits the
practitioners—for example, forensic science is all about finding evidence
that ‘person X poisoned person Y with strychnine’, for example (natural
causes cannot account for person Y’s body containing strychnine, so someone,
an intelligent agent, was responsible). Likewise, the SETI program is tacit agreement
that science can tell the difference between natural causes and intelligent causes
(certain patterns on radio signals from outer space could not be explained as originating
from natural forces). Also, archaeology is much about recognising that an axe-head,
for example, was created by an (unseen) intelligent agent, because the structure
of an axe-head is so unlikely to arise from natural chemical and physical processes.
See the article A brief history of design.
It is the atheistic bias of modern practitioners of science that prevents them from
seeing the abundant evidence, right under their noses, for the unseen Creator of
life. There is more evidence than there ever has been for there being a Creator.
Unbelieving scientists are in willfully ignorant denial (Rom.
1:20 ff.,
2 Peter 3).
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