IX A
probabilistic interaction model between the PO2 P.A.L. evolution
and the
biological evolution
After calcium and iodine, a third probabilistic
interaction application between the environmental evolution and the biological
evolution is proposed. It relates to the free molecular oxygen rate evolution
in the Earth's atmosphere during ages, which can also be regarded as a stimulus
to which the organisms, its origin and its consequences react.
I The
PO2 P.A.L. atmosphere enrichment
In the present state of knowledge, the data on the
atmospheric oxygen rate, during various geological periods, are full of
uncertainties, discussed by the various authors and prone to permanent calling
in question, with the researchers works thread. In what follows, we tried,
nevertheless, to establish a probable middle increase chronology in the oxygen
rate in the Earth's atmosphere. Because of the preceding reserves, one must
regard this chronology various stages more as magnitude orders that like
precise and rigorous datings (Holland 1984-1998; Mason 1992). It is not
excluded, moreover, that the PO2 P.A.L. rate knew fluctuations during
geological periods.
Crust/ocean/atmosphere system enrichment in free
PO2 P.A.L. intervened, mainly, following photochemical reactions grouped under
the photosynthesis generic term (Rybak 1974) and, marginally, of the water
vapor photolysis. This process is, presently, primarily, the plants fact. One
considers the free molecular oxygen present percentage at 5 % oxygen present
total at the earth's crust surface (Schidlowski, Eichman 1977).
We indicate below the earth's atmosphere in PO2
P.A.L. enrichment principal stages since the earth origin (4,6 Billion Years)
until today, of which we gave, to Chapter VI, the essential data. The figures
indicated are based, either on geological arguments (various radioactive
elements isotopic ratios, U 238, K 40, C 14, etc...), or on biological
arguments (biological processes physiological thresholds: aerobiosis, collagen
production, cutaneous respiration, etc...).
1) Hadean (4,6 to 3,9 B.Y.) the earth
paramount atmosphere is made up mainly hydrogen, methane and ammonia
(planetologic arguments). This time intense volcanic degazifications do not
contain free molecular oxygen. PO2 P.A.L. = 0
2) Archean (3,9 to 2,5 B.Y.) uraninite
deposits (UO2.) and pyrite (FeS2) until towards 2,3 B.Y. indicate atmosphere
not-oxydative conditions with PO2 P.A.L. rates probably going from 0,0005 to
0,005 (Holland 1998). PO2 P.A.L. = > 0,0005
3) Proterozoic (2,5 to 0,544 B.Y.)
a) Between 2,8
and 1,8 B.Y., B.I.F. deposits (Banded Iron Formations - ribboned iron
Formations) alternate layers rich and low in magnetite (FeO4) (Guntflint Chert
1,9 B.Y.), also indicating not-oxydative atmosphere.The photosystème II,
appeared towards 2,7-2,5 B.Y. seems to have been dominating and to have caused
the increase in the O2 molecules in the atmosphere. Abundance peaks between 2,5
and 2 B.Y., coinciding with the uraninites disappearance indicate an increase
in the PO2 P.A.L. rate (Holland 1998). PO2 P.A.L. = > 0,005
b) The Red Beds
(Red Formations) hematite (FeO3) deposits appear towards 2,00 B.Y., indicating
oxydative atmosphere conditions and lead to the B.I.F. disappearance towards
1,8/1,7 B.Y. with the ozone layer O3 development (Levin). The increase in the
molecules O2 in the atmosphere allows the emergence of the oldest known aerobic
eucaryote cells, approximately 1,9 B.Y. old (Gryptania spiralis - Pan Terra
1996); 0,01 threshold for the protists aerobic breathing (Holland 1998). PO2
P.A.L. = > 0,01
c) Vendian
(0,565 B.Y.) Between 0,750 and 0,550 B.Y., the carbon isotopic composition
suggest an appreciable increase in the PO2 P.A.L. rate before the cambrian era
(Hoffmann, Kaufman, Halverson 1998). The geochemical data clearly indicate a
rise in the PO2 P.A.L. rate right before the Vendian macroscopic animals
appearance. They also show a phytoplankton dynamic evolution at the
Precambrian/Cambrian (Knoll 1996) border. In addition, the apparition of the
ediacarian fauna of soft body metazoa requires, for the collagen, muscles
production and the cutaneous respiration (Dickinsonia: 1 meter length for a maximum
thickness of 6 mm), a 0,07 PO2 P.A.L. minimum (Towe 1970 - Bruce Runnegar 1982
- Rudolf, Elizabeth Raff). PO2 P.A.L. = > 0,07
4) Paleozoic
(0,544 to 0,250 B.Y.)
a) Cambrian
(0,544 to 0,505 B.Y.) "the cambrian explosion", with its various
episodes, S.S.F. (Small Shelly Fossils), tommotian and atdabanian radiations,
the Burgess Shale fauna, implies an increase in PO2 P.A.L. necessary to the
organisms complexification and their biomineralization. The correlation between
PO2 P.A.L. and the living organisms evolution is corroborated by many data
compilation which we indicated in Chapter VI and which we point out here. The
analysis of these data (Rhoads, Morse 1971) made it possible to show the
relation between the dissolved oxygen level and the fauna benthic presence in
the basins on low oxygen level, in the Black Sea (Bacescu 1963), the Gulf of
California (Parker 1964), the Basin of Santa-Barbara (Emery, Hulsemann 1961)
and the Basin of San Pedro (Hartman 1955, 1966). They established that faunas
can be classified in three facies correlated at different PO2 P.A.L. rates. With
a value < 0,1 ml/l (approximately 0,01 PO2 P.A.L.), the marine sediments are
primarily metazoa benthic deprived; for a value ranging between 0,3 ml/l and 1
ml/l (between approximately 0,03 and 0,10 PO2 P.A.L.), benthic faunas are made
up small species mainly with soft body; when the level is higher than 1 ml/l
(approximately 0,10 PO2 P.A.L.), faunas are relatively varied and made up many
species which secrete skeletons limestones. Similar relations were observed in
the Saanich split in the Vancouver Island (Tunnicliffe 1981). Rhoads and Morse
proposed that these relations between the faunas emergence and the oxygen rates
dissolved in these basins are regarded as analogues with the metazoa groups
development during the Proterozoic last stages and the Phanerozoic first
stages. PO2 P.A.L. = > 0,10
b) Ordovician
(0,505 to 0,438 B.Y.) The first appearance of terrestrial life would go up in
middle Ordovician where terrestrial spores traces are found (0,449/0,458 M.A.-
Jane Gray) but not from vascular plants.The first spores would be perhaps dated
from Cambrian. The PCO2 P.A.L. level before 0,440 B.Y. would have been higher
16 to 18 times on its present level (Crayton J.Yapp 1998). PO2 P.A.L. =
> 0,10
c) Silurian
(0,438 to 0,408 B.Y.) If the possibility of plants and terrestrial animals is
probable in Ordovician, their obviousness is established in Silurian with the
plants vascular fossils (Cooksonia), perhaps of Lycophytes (Baragwanathia?),
mushrooms (ascomycetes) and Arachnida and millipede first fossils (Taylor and
Taylor 1993). The analysis, by stable isotopes geochemical methods, makes it
possible to provide the oxygen lower level rate, during the last 440 million
years. This rate would not be lower than 0,13 (Crayton J.Yapp 1998). PO2
P.A.L. > 0,13
d) Devonian
(0,408 to 0,360 B.Y.) From upper Silurian to higher Devonian, one attends a
considerable development of the vegetable cover by terrestrial vascular plants
with the sheets, roots, secondary tissues and seeds acquisition. Concomitantly, the PCO2 P.A.L.. rate falls quickly and in a
very significant way (Algeo and Scheckler 1998). An imbalance between the
oxygen production by the carbon cycle and its consumption by the sulphur cycle,
by only 5 %, can increase the PO2 P.A.L. rate of 50 % in 40 million years. The
iron cycle can also intervene in this imbalance. On the long term, a balance is
roughly established between the sulphur cycle and the carbon cycle which is an
atmosphere/ocean/terrestrial crust system redox state major element (Holland
1984). During middle and higher Devonian, the increase in the vegetable biomass
accelerates the atmospheric CO2 "pumping" level towards the ground
and establishes a carbon cycle new long-run equilibrium, between its production
and its consumption, which is maintained until our days (Algeo, Scheckler and
Maynard 1998). It is estimated that the atmospheric PCO2 P.A.L. level between
Silurian and higher Devonian is divided by 5 or 6 (Berner 1994). One can suppose,
reciprocally, an increase in atmospheric PO2 P.A.L. of the same magnitude
order. This assumption is corroborated by Heinzinger, Schidlowski and Junge
work (1974). These authors, by comparing the isotope § 18 O value (11,4 o/oo
SMOW), in meteorite magnetite spangles dating from higher Devonian, found
values around 0,65 (11,4/17,6) of those of the recent samples § 18 O (17,6 o/oo
SMOW). Other magnetite spherules, dating from Oligocene gave values appreciably
equivalent to those of today (17,4 o/oo SMOW). The atmospheric isotope § 18 O
respective values give, for superior Devonian 17,3 o/oo SMOW, for the Oligocene
one, 23,3 o/oo SMOW and 23,5 o/oo SMOW for today is a value of 17,3/23,5 = 0,74
PO2 P.A.L. for Devonian. PO2 P.A.L. = 0,65 to 0,74
e) Carboniferous/Permian (0,360-0,250 B.Y.)
5) Mesozoic (0,250 to 0,065 B.Y.)
The carboniferous flora and the terrestrial
vascular plants radiations during the Permian and the Triassic, with the PCO2
P.A.L. rate decrease (Berner 1994), could carry the PO2 P.A.L. oxygen rate
which one estimates at 0,93 with the Gymnosperms blooming (Coniferals) until
lower Cretaceous. PO2 P.A.L. = 0,93
6) Cenozoic (0,065 B.Y. - present)
Of the Cretaceous until our days, develop
Angiospermae. A last increase in PO2 P.A.L. partial pressure had to occur
during the Cretaceous various oceanic anoxic events OAEs (Holland 1984),
carrying it to its present value with the Cenozoic one. PO2 P.A.L. = 1
II PO2
P.A.L. atmosphere enrichment biological factors
As we indicated higher, crust/ocean/atmosphere
system enrichment in free PO2 P.A.L. intervened, mainly, following
photochemical reactions grouped under the photosynthesis generic term (Rybak
1974) and, marginally, of the water vapor photolysis. This process is,
presently, primarily, the product of the plants (Knoll 2000).
This environment parameter, that the probabilistic
model regards as a stimulus to which the organisms react is, as we will see it
below, itself produced by the living organisms evolution during geological
times, from the procaryotic photosynthetic unicellular organisms then
eucaryotes and later plants.
The following table establishes the correlation
observed between the producing oxygen organisms biological evolution and the
increase in the atmosphere free molecular oxygen PO2 P.A.L. partial pressure.
This table indicates: 1) the billion years age 2) producing oxygen present
organisms 3) estimated PO2 P.A.L. rates.
Hadean
4,6: no life, possible water vapor photolysis, null
or negligible PO2 P.A.L. (Holland 1984). PO2 P.A.L. = 0.
Archaean
3,85: Isua
carbonated sediments (Mason 1992), life traces (carbon 12, Akilia island)
(Mojzsis and Arrhenius 1996), null or negligible PO2 P.A.L.. PO2 P.A.L. =
0
3,5: life
traces, stromatolites, archaes (?), autotrophic bacteria, oxygen not-producing,
filamentous bacteria, Australia Warrawoona fossils (North Pole); null or
negligible PO2 P.A.L. (Mason 1992). PO2 P.A.L. = 0
2,8:
stromatolites, proalgae, blue algae cyanobacteria precursors, procaryotic, anaerobic
photosynthesis (chemosynthesis) and aerobic with oxygen release (Schidlowski,
Eichman 1977), (Schopf 1977), (Whitaker, Klein 1977), (Brack, Raulin 1991),
(Holland 1998). PO2 P.A.L. = < 0,005
Proterozoic
2,5 to 2,3:
B.I.F. (Banded Iron Formations) and uraninites, more than 58 listed spheroid
microfossils genera (Boureau 1986), procaryotic aerobes, PO2 P.A.L. 0,005 to
0,01 (Holland 1984), (Mason 1992). PO2 P.A.L. = 0,005 to 0,01
2,0: B.I.F.,
Gunflint Chert ribboned iron formations, ozone layer, abundant aerobic
procaryotic blue algae, 10 microns in diameter, similar to present Nostocs, PO2
P.A.L. from 0,01 to 0,02 (Schidlowski, Eichman 1977), (Margulis 1977), (Holland
1984), (Mason 1992). PO2 P.A.L. = 0,01 to 0,02
1,9 to 1,5:
hematite red layers, first known aerobic eukaryote cells (Gryptania spiralis -
Pan Terra 1996), cells increase, acritarchs (40 microns diameter), mitosis,
meiosis, green and red algae. PO2 P.A.L. > 0,02 < 0,07
1,5 to 0,565:
acritarchs radiation towards 0,900/0,850 then quasi-disappearance towards
0,600; first unicellular green eucaryote algae fossils equipped with distinct
chloroplasts; first multicellular plants fossils with structures similar to
salads and kelps (1,4-1,2 Butterfield 1998); increase in the eucaryote
microflore and reduction in the procaryotic microflore, in particular because
of the eucaryotes greatest capacity to use available phosphate (Lehman, Botkin,
Likens 1975); increase in the photosynthesis and the free molecular oxygen rate
(Cloud 1990) and in the organic carbon sedimentation (Knoll 2000), Algae era. PO2
P.A.L. = < 0,07
0,565 to 0,544: phytoplankton dynamic evolution which involves an increase
in the atmospheric oxygen level right before the macroscopic Ediacara fauna
appearance at the Precambrian end (Knoll 1996), (Heinrich D. Holland 1998). PO2
P.A.L. > 0,07 = < 0,10
Paleozoic
0,544 to 0,505: (Cambrian): possible terrestrial first spores (Brasier
1979), (Bengtson, Conway 1984); " Thallophyta era " (British
Columbia, Conway Morris and Robinson 1988). PO2 P.A.L. = > 0,10
0,505 to 0,438 (Ordovician): first terrestrial plants spores fossil obviousnesses,
terrestrial vascular Crytogams possibilities, Protopsylophytes in higher
Ordovician (Auboin, Brousse, Lehman 1985), (Babin 1991). PO2 P.A.L. =
> 0,10
0,438 to 0,408: (Silurian): terrestrial vascular plants and terrestrial photosynthetic
production of O2 obviousness and development which supplants the primarily
marine photosynthetic production former to Silurian (Holland 1984). In higher
Silurian, first poikilotherms
(Cooksonia) and Lycopodophytes (Baragwanathia?),
"Thallophyta era", photosynthesis on the continents (Theobald, Gama
1969), (Auboin, Brousse, Lehman 1985), (Babin 1991), (Crayton J.Yapp 1998). PO2
P.A.L. > 0,13
0,408 to 0,360: (Devonian): continental flora diversification, terrestrial vegetable
cover considerable development, Pteridophyta explosion (Psilophytines - Rhynie
flora -, Lycopodiophytines, Equisetophytines, Filicophytines, etc...);
"vascular Cryptogams era" (Theobald, Gama 1969), (Auboin, Brousse,
Lehman 1985), (Babin 1991), (Holland 1984). First Spermatophyta. First forests
with high sizes trees (of 8 m up to 30 m). Vegetable diversification is
regarded as a "devonian explosion" (R. Goldring 1978). It is estimated
that the terrestrial ecosystems photosynthetic productivity exceeds that of the
marine ecosystems of a factor 2 (Whittaker, Likens 1975; McLean 1978).
Terrestrial vegetable photosynthesis acceleration with the PCO2 P.A.L. fast
fall (Berner 1994) and PO2 P.A.L. significant growth (Heinzinger, Schidlowski,
Junge, 1974). PO2 P.A.L. = 0,65 to 0,74
0,360 to 295:
(Carboniferous), immense marshy forests, carboniferous flora supporting the
coal formation, Pteridophyta considerable development, Pteridospermales and Cordaitales
appearance.
0,295 to 0,250: (Permian) and 0,250 to 0,065 (Mesozoic) Phanerogams
development, " Gymnosperms era " then of Angiospermae (starting from
the lower Cretaceous - Ranunculus ferresi) (Theobald, Gama 1969), (Auboin,
Brousse, Lehman 1985), (Babin 1991), (Holland 1984), (Heinzinger, Schidlowski,
Junge, 1974). PO2 P.A.L. = 0,93
Cenozoic
0,065 to Present: (Tertiary - Quaternary): Angiospermae radiation
(Monocotyledoneae and Dicotyledoneae). PO2 P.A.L. = 1
If one analyzes the earth's atmosphere enrichment,
from Archaean to Cenozoic, one notes that this average atmosphere enrichment is
concomitant with the successive appearance, in the biosphere, of increasingly
powerful oxygen producing organisms, from the Archaean cyanophyta and the blue
and green procaryotic algae to the pluricellular " higher " eucaryote
organisms, like present Angiospermae. One can distinguish, in the PO2 P.A.L.
rate evolution five significant phases or thresholds:
1st phase (2,8 to 2): cyanobacteria, procaryotic
algae, monera. PO2 P.A.L. = < 0,01
2nd phase (2 to 0,565): monera, protists,
acritarchs, first multicellular plants, Schizophyta and Thallophyta, "
algae era ", primarily marine plants. PO2 P.A.L. = < 0,07
3rd phase (0,565 to 0,438): Thallophyta
development, first terrestrial spores in Ordovician, first terrestrial vascular
plants in higher Ordovician. PO2 P.A.L. > 0,13
4th phase (0,438 to 0,360): development in Silurian
then " explosion " in Devonian of the Pteridophyta vegetable cover,
" vascular Cryptogams era ", primarily terrestrial plants, with
photosynthetic productivity double that of the sea plants (Whittaker, Likens
1975; Mc Lean 1978), PCO2 P.A.L. fast fall and concomitant increase in PO2
P.A.L. PO2 P.A.L. = 0,65 to 0,74
5th phase (0,360 - Present): terrestrial flora
considerable development at Carboniferous and Permian, " Gymnosperms era
" from Permian to the lower Cretaceous, " Angiospermae era "
from the lower Cretaceous to Present with a PO2 P.A.L. rate = 1 at the Cenozoic
PO2 P.A.L. = 1
This PO2 P.A.L. evolution, from Archaean to
Present, is proposed like model, with uncertainties which are attached to it,
in the entirely reliable and precise data absence. The most coherent values
that one can retain, in the knowledge present state are: PO2 P.A.L.: 4,6
(Hadean) = 0; 2 (Proterozoic) = < 0,01; 0,565 (Vendian) = < 0,07; 0,438
(Silurian) > 0,13; 0,408 to 0,360 (Devonian) = 0,65 to 0,74; Present = 1.
The preceding restrictions do not affect the process total interpretation.
The correlation between the producing oxygen
organisms evolution, of the aerobic monera to the terrestrial plants, from
Precambrian to Cenozoic, and the partial pressure of free molecular oxygen in
the atmosphere concomitant enrichment, arises clearly from the preceding table.
If the tectonic, volcanic, climatic phenomena, the sulphur, carbon, iron
cycles, the terrestrial crust/ocean/atmosphere system redox state importance
(Schidlowski, Eichman 1977) and many other factors could play a non-negligible
role in the PO2 P.A.L. evolution, it appears, nevertheless, that the prevalent,
probabilistic factor, of this evolution is the rise of the vegetable kingdom,
from Archaean to our days, from Schizophyta and Thallophyta primarily watery to
the Pteridophyta and Spermatophyta, primarily terrestrial, with increasing
productivity. This corresponds to our probabilistic interaction model between
the environmental evolution and the biological evolution.
After having highlighted the vegetable evolution
probabilistic influence on an environment parameter, partial pressure PO2
P.A.L., we will study the opposite interaction, the evolution probabilistic
influence of partial pressure PO2 P.A.L. on the biological and, more
particularly, animal evolution.
III
Concomitant probabilistic evolution in PO2
P.A.L.
increase in the atmosphere and in animal evolution
According to the probabilistic model, the PO2
P.A.L. the rate evolution in the atmosphere, from the Archaean to our days, is
a prevalent parameter, probabilistic, of the living organisms evolution, from
procaryotes to the "upper" Vertebrates. We noted (II) that the
vegetable evolution had considerably modified, primarily by photosynthesis,
since the earth origin until today, the PO2 P.A.L. rate. Reciprocally, the
organisms reacted, while evolving, with this chemical parameter rate
modification of their free molecular oxygen environment. Just as the calcium,
iodine elements, or others like C, S, P... or like the electromagnetic, sound
waves..., oxygen can be regarded as an environment stimulus to which react the
organisms. We propose that, in accordance with our model, the animal evolution
is correlated, chronologically, in a probabilistic way, during geological
times, with the free molecular oxygen content present in the hydrosphere and
the earth's atmosphere. PO2 P.A.L. having passed, from Archaean to our days
from 0 to 1 (I), it results from it that the the organisms reaction evolved,
concomitantly with this free molecular oxygen stimulus variation, this
evolution appearing primarily by a modification of the respiratory systems.
Oxygen is not essential to the life. In the
anaerobiose, there is hydrogen transfer of an organic molecule to another
(fermentative mode) whereas in aerobiosis, this transfer passes by oxygen. The
breathing significant result is less the water and carbon dioxide formation
that of A.T.P. By glycolysis and the fermentative way, the anaerobic cells
manufacture, starting from glucose, 2 A.T.P. molecules, whereas the same
reaction, continuing with breathing in the aerobic cells, produces 32 A.T.P.
molecules (Krebs cycle oxydative phosphorylation) that is to say 16 times more
energy (Mason 1992, Robert J.Huskey 1998).
As we evoked above (Chapter VI: The cambrian
explosion), the relations which exist between free molecular oxygen and the
organisms are complex. We pointed out the two principal respiratory modes:
watery breathing (cutaneous and branchial) and air breathing (cutaneous,
trachean and pulmonary) just as the mixed systems (tracheangills, " water
pulmonary "), breathing various physical and chemical parameters
(capitance, temperature, Fick law, etc...), the multiple morphological and
physiological devices which improve it (lashes, whips, gills, circulatory
apparatus, blood or hemolymph, respiratory pigments, etc...) (Turquier 1994).
An animal energy consumption analysis results in
its oxygen uptake. This one depends, at the Vertebrates, on the heart size and
the cardiac beats frequency. It is admitted that the cardiac flow is correlated
with the animal oxygen uptake at rest (Turquier 1994). In the following table,
we indicated, for various animals groups, the heart weight, in % of the body
weight, the cardiac flow and the average oxygen consumption:
Heart weight, in % of the body weight: Fishes 0,2 -
Amphibia 0,5 - Reptiles 0,5 - Mammals 0,6 - Birds 0,8 (2,56 for the Thrush -
Grassé 1992).
Cardiac flow, in ml kg-1 min-1: Fishes: Teleosts
9,3, Selacia 22 - Amphibia (Urodela, Anoura) 30 - Reptiles: Iguana 44, Tortoise
55 - Mammals: Man 85, Dog 150 - Birds (Duck): 287.
Consumption O2, in ml kg-1 H-1: Cephalopods 60/120
(much less by Nautile) - Fishes (Trout) 100 - Amphibia (Frog) 70/170 - Reptiles
50 - Arachnida 13/356 - Mammals, from 210 (Man) to 7400 (Shrew) - pulmonary
Gastropods (Limax flavus) 360 - Birds, hen egg 200, average 700 (Rahn, Ar,
Paganelli 1986) (Turquier 1994).
With this table reading, one can make the following
observations:
1) At the Vertebrates, the heart weight in % of the
body weight varies in the same direction as the cardiac flow (from 0,2 to 0,8
and 9 to 287).
2) the oxygen uptake is, on average, parallel with
the cardiac flow and grows, from the Invertebrates with branchial breathing to
the organisms, Invertebrates and Vertebrates, with air or mixed breathing
(Amphibia, Reptiles, Arachnida, Mammals, Birds and even pulmonary Gastropods).
3) It is necessary to moderate these observations
by noting that, at the Vertebrates, with equal weight, the average oxygen
consumption is 14 times more significant at Homeotherms than at Poikilotherms (with
20 ° C): 700 ml H-1 for a Mammal of one kg for 50 ml H-1 for a Reptile of one
kg (Turquier 1994).
4) In addition, at the homeotherm Vertebrates, the
oxygen quantity consumed per weight unit is all the more large since the animal
is smaller: of 210 ml O2 kg-1 H-1 at the Man to 7.400 ml O2 kg-1 H-1 at the
Shrew (body mass 5 g).
The evolution, the increase in PO2 P.A.L., during
geological times, from Hadean to the Present one, that the preceding analyses
made it possible to highlight, were not without having a determining influence
on the animal life evolution. We indicated that this PO2 P.A.L. rate,
environment parameter, can be regarded as a stimulus to which reacted the
organisms, following the example calcium, iodine, etc... or physical factors
like the electromagnetic waves, the sound waves, etc... While increasing, the
PO2 P.A.L. rate opens biological process possibilities, starting from certain
thresholds. Thus the 0,01 PO2 P.A.L. threshold for the protists aerobic
breathing (Holland 1998) is it necessary, like the collagen, muscles production
and the cutaneous respiration requires a 0,07 PO2 P.A.L. minimum (Towe 1970 -
Bruce Runnegar 1982 - date of Rudolf, Elizabeth Raff).
In the table which follows, we tried to establish
the correlation between 1) the earth age (of billion years), 2) the PO2 P.A.L.
corresponding rate, 3) biological and respiratory processes permitted by the
PO2 P.A.L. rates, 4) animal groups appearance (and protophytes) attested by
their fossils. Given the documentation gaps and uncertainties, the PO2 P.A.L.
rates must be considered, as we indicated higher, more like reference marks and
magnitude orders than like rigorous data, and more particularly at Archaean and
Proterozoic. This table is not exhaustive and can be only simplifying, given
the biological phenomena complexity. It counts the chronology of the apparition
of new biological and respiratory processes as its most significant species
correlation. We will be able to note that this appearance of the species is not
fortuitous. It is contemporary or posterior on its biological possibility date.
This, which could be regarded as a self-evident truth, expresses, in fact, the
relation which exists between a biological process possibility permitted by the
PO2 P.A.L. rate and the organisms probabilistic reaction to the oxygen
stimulus, as we proposed higher.
Hadean
4,6: PO2 P.A.L. = 0 - abiotic earth's crust
- earth constitution, intense volcanicity, primitive atmosphere by coat
degazification, rich in methane, hydrogen and ammonia, probably carbon dioxide
and water vapor (Brack, Raulin 1991).
Archaean
3,80-3,85: PO2
P.A.L. = 0 - possible anaerobic biological processes - bacterial synthetic
activity in the carbonated Isua sediments (Schidlowski 1988) (Mason 1992),
Akilia island (Mojzsis and Arrhenius 1996), reduced carbon, autotrophic and
chimiotrophes organisms, methanogenese, photosynthetic sulphur bacteria golden
age (Nisbet 1987), archaebacteria (Woese 1981), unicellular (or acellulars?)
organisms, ARN world? LUCA (Last Universal Common Ancestor) hyperthermophile
archae? (Forterre 1997), or alive tree with primitive cells generating three
primitive groups: bacteria, archaebacteria and eucaryotes (Carl Woese 1998 ;
W.Ford Doolittle,1999) - procaryotic cells.
3,5: PO2
P.A.L. = 0 - possible anaerobic biochemistry and fermentation - anaerobic
autotrophic microbial forms, archaebacteria, purple anaerobic photosynthetic
bacteria (Margulis, Sagan 1989), first Warrawoona Australia stromatolites
(North Pole) (Mason 1992), filamentous microfossils from blue and green algae
(Awramik 1977), (Schopf 1991), thermoacidophiles organisms and photosynthetic
eubacteria ? (Nisbet 1987), - procaryotic cells.
3,0: PO2
P.A.L. < = 0,002-0,003 - fermentation, possible aerobic biochemistry at
the 0,002 pressure (Chapman, Schopf 1983) - aerobiosis beginning, oxygenates
produces by photosynthesis (Schidlowski, Eichman 1977), collected by the
dissolved iron in water to form ferric oxides (Wilson 1993), procaryotic
microbes age who are flourishing (cyanobacteria), for the majority obligatorily
photoautotrophic (Rambler, Margulis, Barghoorn 1977), (Nisbet 1987), coccoids
(Boureau 1986) - procaryotic cells..
2,8-2,6: PO2 P.A.L. < 0,01 -
stromatolites, blue and green photoautotrophic algae cyanobacteria precursors
(Schidlowski, Eichman 1977), possible aerobic organisms (Chapman, Schopf 1983)
- anaerobic photosynthesis (chemosynthesis) and aerobic with oxygen release
(Schidlowski, Eichman 1977), (Schopf 1977), (Whitaker, Klein 1977), (Brack,
Raulin 1991), (Holland 1998), chlorophyllian photosynthesis (Boureau 1986),
ribboned iron formations, ozone layer beginning, first aerobic organisms
(unicellular procaryotes), (Holland 1984), (Mason 1992), (Wilson 1993), many
aerobic photosynthetic species (Margulis, Sagan 1989), photosystème II
appearance (Holland 1998) - procaryotic cells.
Proterozoic
2,5-2,3: PO2 P.A.L. < 0,01 - (B.I.F.,
Banded Iron Formation), uraninites; 58 spheroids microfossiles genera were
listed at the Proterozoic beginning (Holland 1984), (Boureau 1986), (Mason
1992) - procaryotic cells. .
2,0: PO2 P.A.L. = > 0,01 - possible
anaerobic and aerobic organisms with fermentation and breathing (Krebs cycle),
(Chapman, Schopf 1983) - stromatolites, ozone layer reinforcement (Margulis
1977), anaerobic and aerobic organisms Gunflint Chert B.I.F., filamentous
procaryotic cells (Gunflintia minuta) and coccoids, (Tyler, Barghoorn 1954),
abundant aerobic procaryotic blue algae, 10 microns in diameter, similar to
present Nostocs , 18 species known flora arranged in 14 genera (Boureau 1986),
purple and green photosynthetic microbes, with oxygen optional production,
A.T.P. production by the present cyanobacteria aerobic ancestors (Margulis,
Sagan 1989), (Holland 1984), (Mason 1992) - procaryotic cells.
1,9-1,5: PO2 P.A.L. > 0,01 - the hematite
red layers, (FeO3) appearing towards 2,00 indicate oxydative atmosphere
conditions and lead to the B.I.F. disappearance towards 1,8-1,7 and the ozone
layer O3 development (Levin). The increase in the molecules O2 in the
atmosphere allows the oldest known aerobic eucaryote cells emergence,
approximately 1,9 B.Y. old (Gryptania spiralis - Pan Terra 1996); 0,01 PO2
P.A.L. threshold for the protists aerobic breathing (Holland 1998); cells
increase, acritarchs (40 to 60 microns in diameter), mitosis and meiosis
appearance, A.T.P. production by Krebs cycle oxydative phosphorylation, genetic
recombinations (Boureau 1986), endosymbiose?, (Schopf 1977), (Margulis, Sagan
1989), (Danchin, Debrenne 1992), eucaryote algae (Wilson 1993) - eucaryote
cells.
1,5-0,565: PO2
P.A.L. > 0,01 = < 0,07 - acritarchs radiation towards 0,900-0,850
then quasi-disappearance towards 0,600; unicellular green eucaryote algae first
fossils equipped with distinct chloroplasts; multicellular plants first fossils
with structures similar to salads and kelps (1,4-1,2 Butterfield 1998);
increase in the eucaryote microflore and reduction in the procaryotic
microflore, in particular because of the eucaryotes greatest capacity to use
available phosphate (Lehman, Botkin, Likens 1975), (Holland 1984); Montana
multicellular algae, tracks and burrows traces (Coelomates?) (Babin 1991) - eucaryote
algae era.
0,565-0,544
(Vendian): PO2 P.A.L. > 0,07 = < 0,10 - phytoplankton dynamic
evolution involving an increase in the atmospheric oxygen level right before
the metazoa macroscopic fauna appearance with soft body of Ediacara at the
Precambrian end (Knoll 1996), (Hoffmann, Kaufman, Halverson 1998), (Heinrich D.
Holland 1998); ediacarian metazoa fauna production possibility with soft body
which requires, for the collagen, the muscles production and the cutaneous
respiration (marine worm Dickinsonia: 1 meter length for a 6 mm maximum
thickness), a 0,07 PO2 P.A.L. minimum (Towe 1970 - Bruce Runnegar 1982 -
Rudolf, Elizabeth Raff); symbiotic relations between photosynthetic algae and
animal organisms (Hallock-Muller) - 25 species and 15 genera Ediacara fauna
belonging to 3 phyla: Cnidae majority (Coelenterata 67 % of which the three
quarters are medusoids organisms, " jellyfishes era "), Annelida (25
%, Dickinsonia), Arthropoda (5 %) and incertae sedis (Cloud, Glaessner 1982),
stromatolites built by the blue and green algae regression (Avramik 1977);
metazoa with soft bodies, first metazoa with calcium phosphate and carbonate
shells among the most recent fossils - diploblastic and triploblastic metazoa.
Paleozoic
0,544 to 0,505 (Cambrian) PO2 P.A.L. = > 0,10 : possible cutaneous and
branchial watery breathing; many biological innovations, coelomic circulation,
hemal or blood circulatory apparatus, respiratory pigments, calcium phosphate
and/or carbonate exoskeleton secretion, intense phosphogenese; Cambrian
"fossiliferous explosion", from Tommotian to middle Cambrian, with
the sub-kingdoms and faunas diversification with increasingly varied shells and
exoskeletons, rich in calcium carbonates and phosphates (Spongiae, Archeocyata,
Cnidae, Brachiopods, Molluscs, Arthropoda, Echinodermata, etc...), cf Chapter
VI "the cambrian explosion" (Stanley 1976, Rhoads, Morse 1971,
Brasier 1979, Conway Morris 1982, Valentine 1986, etc...); possible first
terrestrial spores, (Brasier 1979), (Bengtson, Conway 1984); " Thallophyta
era " (British Columbia, Conway Morris and Robinson 1988); radiations:
approximately 400 genera, 120 families (Devillers and Chaline 1989).
0,505 to 0,438 (Ordovician): PO2 P.A.L. = > 0,10 : The terrestrial life first
appearance would go up in middle Ordovician where terrestrial spores traces are
found (0,449/0,458 B.Y. Jane Gray) but not from vascular plants.The first
spores would be perhaps dated from Cambrian. The first terrestrial vascular
plants Crytogames, the Protopsylophytes, would date from higher Ordovician
(Auboin, Brousse, Lehman 1985), (Babin 1991). Many plants and animals species
adaptive radiations; at the Ordovician end one counts approximately 1400 genera
and 470 primarily marine metazoa families (Devillers and Chaline 1989). The PCO2
P.A.L. level before 0,440 B.Y. would have been higher 16 to 18 times its
present level (Crayton J.Yapp 1998). First marine scorpions (Eurypteride -
Petrunkevitch 1960, Wills, Briggs and Fortey 1994). First established
Vertebrates (Sacabambaspis, Agnatha of higher Ordovician - Gagnier 1986).
0,438 to 0,408 (Silurian): PO2 P.A.L. > 0,13 : If the terrestrial plants and
animals possibility is problable in Ordovician, their obviousness is
established in higher Silurian. The terrestrial vascular plants development and
the O2 terrestrial photosynthetic production supplants the primarily marine
photosynthetic production former to Silurian (Holland 1984). First vascular
plants fossils, the Psylophytes (Cooksonia) and the Lycopodophytes
(Baragwanathia?) attest increase in the photosynthesis which grows considerably
on the continents (Theobald, Gama 1969), (Auboin, Brousse, Lehman 1985), (Babin
1991). Development in Silurian then explosion in Devonian of the Pteridophyta
vegetable cover, " vascular Cryptogams era ", primarily terrestrial
plants, with photosynthetic productivity double that of the sea plants
(Whittaker, Likens 1975; Mc Lean 1978); fall fast of PCO2 P.A.L. (Berner 1994)
and concomitant increase in PO2 P.A.L. (Crayton J.Yapp 1998). Air breathing
possibilities (atmospheric gas oxygen absorption and not only dissolved in
water) with the increase in PO2 P.A.L. Mushroom fossils are counted
(ascomycete) (Taylor and Taylor 1993). Pulmonary and tracheans apparatuses
first appearance at the Vertebrates and the Invertebrates. First Invertebrates
fossils with air breathing, Arachnida (oldest known, a trigonotarbide gone back
to 0,414 with pulmonary respiration - Petrunkevitch 1960), marine scorpions
(higher Silurian Palaeophonus) (Moret 1966), (Theobald, Gama 1969), (Grassé
1993), (Taylor and Taylor 1993); myriapoda. Exoskeletons and endoskeletons
secretion, swim bladder acquisition at Actinopterygia (higher Silurian) which
will become a pulmonary at Dipnoi in Devonian (Babin 1991), (Grassé 1992).
0,408-0,360
(Devonian): PO2 P.A.L. 0,65 to 0,74 - Antiquated Pteridophyta
Development (Rhynia - Aglaophyton major) in the Scottish marshes (Jean Broutin
2000). Various modes of air, cutaneous, pulmonary, trachean, mixed breathing
simultaneous diversification. " Explosion ", starting from Devonian,
of air breathing in the Metazoa groups majority and particularly at the
Arthropoda and the Vertebrates (Turquier 1994). Air breathing develops at the
same time on earth and in the aquatic environments.
In the Arthropoda, at Chelicerata as at Antennata,
4 classes out of six adapt to air breathing: 1) Arachnida (Acarina, Protocarus
Crani of Devonian, Theobald, Gama 1969; Spiders with tracheo-pulmonary
respiration of Devonian, Babin 1991, Grassé 1993); 2) Shellfishes
(Malacostraceous: Isopoda, Woodlice, Old Red Sandstones Praearcturus with
pseudo-tracheas, Theobald, Gama 1969, Grassé 1993); 3) Myriapoda (Diplopoda,
devonian Archipolypoda, probably amphibia, Grassé 1993; Archidesmus, Moret
1966); 4) Apterygota Insects (Collemboles with transtegumentary breathing,
Grassé 1993; middle Devonian Rhyniella of Rhynie, Moret 1966); Pterygota
Insects (middle Devonian Rhyniognatha hirsti of Rhynie, Theobald, Gama 1969);
Devonian marine pulmonary Gastropods (Moret 1966).
In the Vertebrate sub-kingdom, among Gnathostoma,
in 2 classes, organisms will develop with a mixed breathing (gills and
pulmonary) in Devonian. The 3 other classes, with entirely air breathing, will
appear later, when the atmospheric PO2 P.A.L. rate increases: 1) Fishes : Selacia,
Arthrodians Placodermi of middle Devonian (Coccosteus) and superior
(Phyllolepis) with gills and pulmonary breathing; middle Devonian
Crossopterygii (Latimeria chalumnae with ossified swim bladder and
nonfunctional pulmonary outline, Grassé 1992); lower Devonian Rhipidistians
with manners amphibia (Osteolepis, Theobald, Gama 1969); Sarcopterygii (lower
Devonian Dipnoi, Maisey 1996; Dipnorhynchus with gills and pulmonary breathing
, Theobald, Gama 1969); 2) Amphibia (higher Devonian Old Red Sandstones, Stegocephalia,
Ichthyostega with air breathing, oldest tetrapode known, Theobald, Gama 1969,
Babin 1991, Pamela Gore 1997). The tetrapoda, equipped with air breathing,
start to conquer the earth from 0,360. Close relations of pulmonary fishes,
they are divided into 2 groups, the Amphibia with mixed and cutaneous breathing
and Amniotes (Reptiles, Mammals and Birds) with entirely air breathing.
0,360-0,295 (Carboniferous) PO2 P.A.L. 0,93 : trachean and pulmonary respiratory
possibilities blooming - Among Amniotes with entirely pulmonary breathing,
Vertebrates class appearance , the Reptiles (Cotylosauria - superior
Carboniferous Diadectes, middle Carboniferous Hylonomus; Pelycosauria -
superior Carboniferous Varanosaurus - Theobald, Gama 1969, Babin 1991). Among
the Invertebrates, Pterygota Insects with trachean breathing rise (Paleopteran:
Paleodictyoptera, Ephemeroptera, Odanotoptera, Stephanian Megasecoptera;
Neoptera: Stephanian Protorthopteroids, inferior and middle Westphalian
Blattopteroids, Theobald, Gama 1969). The Insects presently represent 80 % of
the alive animal species. In the Molluscs, terrestrial Gastropods with
pulmonary respiration emergence which will develop until the Present one
(Stylommatophores, Dendropupa, Zonites, Theobald, Gama 1969). Nemathelminthes
remainders are known with Carboniferous (Theobald, Gama 1969) - certain
Nematodamorpha with cutaneous air breathing have teguments with exoskeleton
(Turquier 1994).
0,295-Present (Permian, Mesozoic, Cenozoic): PO2 P.A.L. 1 - Complete present air respiratory
possibilities - "superior" Vertebrates: Mammals (terminal Triassic,
Rhetian, pulmonary respiration with intense bronchial and alveolar
ramifications, Grassé 1992), Birds (superior Jurassic, Archaeopteryx, complex
bronchial system and air bags), more powerful air breathing at these amniote
homeotherm Vertebrates, in connection with their needs more significant than at
amniote poikilotherm Vertebrates (Reptiles) (see higher). Invertebrates:
Annelida (terricol Oligochaeta, Lombric or Earth Worm, transtegumentary air
breathing, superior Jurassic?; Achaeta, Hirudinea of the Eocene) (Turquier
1994), (Theobald, Gama 1969). Arthropoda, land Decapoda Crustacean (Coenobita,
Birgus latro, Cretaceous, mixed, gill and pulmonary breathing) Theobald, Gama
1969), (Turquier 1994).
IV The
arguments of a probabilistic model
Certain PO2 P.A.L. thresholds make possible the
emergence of biological innovations , new anatomical structures and
physiological processes. This emergence is contingent. The eucaryote cells
aerobic breathing simple possibility does not involve necessarily their
appearance. It is the probability, i.e. the events prevalence where the
mathematical chances are high which transforms the contingency into the most
probable event and, by extension, actually. We propose that the probabilistic
interaction model between the environmental evolution and the biological
evolution is this transformation vector. It is the probability theory which
modifies the simple possibility into reality. The favorable factors existence
to the aerobic breathing or the cutaneous respiration emergence involves thus,
according to the probabilistic model, their appearance, in accordance with
their high chances.
1)
General arguments
a) The PO2 P.A.L. rate growing enrichment during
geological times is concomitant with the different animal taxa chronological
appearance, in connection with the requirements out of O2 for their metabolism,
from the protists to the most demanding metazoa, the Birds. We will specify
low, in chapter 2, this chronology with the PO2 P.A.L. principal thresholds
examination.
b) The darwinian theory accounts for the evolution
by the couple mutations/selection. This couple relates to primarily the
micro-evolution, i.e. the specific evolution, with random transfers and the
favorable transfers to the species selection. This model does not have the
capacity to bring a organisms macro-evolution valid explanation, parallel with
the PO2 P.A.L. rate growth.
c) The macro-evolution, concomitant with the PO2
P.A.L. rate evolution, concerns, simultaneously, taxa, from the very distant
sub-kingdoms, Invertebrates like Vertebrates, protozoa as well as metazoa. It
is about a collective macro-evolution. Nothing, in the darwinian model, makes
it possible to give an account of these simultaneous collective phenomena.
d) The collective macro-evolution in time,
concomitant with the PO2 P.A.L. rate evolution, is also in space. Indeed, the
taxa evolve as well on earth as in water with the PO2 P.A.L. rate growth: in
Devonian, marine scorpions, amphibious myriapoda, marine pulmonary gastropods,
terrestrial arachnida and insects; fishes with gills and pulmonary breathing,
Arthrodians, Rhipidistians, Sarcopterygii, Amphibia with air breathing,
Stegocephalia, Ichthyostega. Here either, the darwinian model does not have
sufficient explanatory capacity.
2)
Biological thresholds
According to the probabilistic model, the
biological evolution proceeds under the environmental factors probabilistic
influence and, in the event, under that of the PO2 P.A.L rate increase, during
geological periods,.The evolution passes by a certain decisive stages number,
conditioned by what one can indicate under the thresholds term. These
thresholds are the minima from which the organisms, protozoa or metazoa, have
the possibility to appear. This emergence possibility is transformed into
reality by the means of the mathematical chances of the probability theory.
These mathematical chances are objective, neutral, contrary to the darwinian
advantages, utilitarian and anthropocentric. In the following diagram, the
correlation between the PO2 P.A.L. biological thresholds appearance (chronology
in million years) and the morphological and/or physiological innovations or organisms
emergence is highlighted.
PO2 P.A.L. = > 0,01 - 2.000 - 0,01 PO2 P.A.L. threshold for the protists
aerobic breathing (Holland 1998) - oldest known aerobic eucaryote cells
emergence towards 1.900 (Gryptania spiralis - Pan Terra 1996).
PO2 P.A.L. > 0,07 = < 0,10 - 565 - 544 (Vendian): Metazoa production threshold
with soft body which requires, for the collagen, muscles production and the
cutaneous respiration (marine worm Dickinsonia), a 0,07 PO2 P.A.L. minimum
(Towe 1970 - Bruce Runnegar 1982 - Rudolf, Elizabeth Raff); metazoa ediacarian
fauna with soft body, first metazoa with calcium phosphate and carbonate shells
among the most recent fossils - diploblastic and triploblastic metazoa.
PO2 P.A.L. = > 0,10 - 544 to 505 (Cambrian): Watery cutaneous and gill
breathing threshold, many biological innovations, coelomic circulation, hemal
or blood circulatory apparatus, respiratory pigments, biomineral respiratory
pigments threshold, calcium phosphate and/or carbonate biomineralization and
exoskeleton secretion threshold (Bacescu 1963), (Emery, Hülsemann 1961),
(Hartman 1955, 1966), (Rhoads, Morse 1971), (Tunnicliffe 1981); Cambrian
"fossiliferous explosion", from Tommotian to middle Cambrian, with
the sub-kingdoms and faunas diversification and increasingly varied shells and
exoskeletons, rich in calcium carbonate and phosphate (Spongiae, Archeocyata,
Cnidae, Brachiopods, Molluscs, Arthropoda, Echinodermata, etc...), (Stanley
1976, Rhoads, Morse 1971, Brasier 1979, Conway Morris 1982, Valentine 1986);
radiations: approximately 400 genera, 120 families (Devillers and Chaline
1989).
PO2 P.A.L. > 0,13 - 438 to 408 (Silurian) - PO2 P.A.L. 0,65 to
0,74 - 408 to 360 (Devonian): Air breathing threshold (oxygen
atmospheric gas absorption and either only dissolved in water) with the
increase in PO2 P.A.L. in Silurian. Pulmonary and trachean apparatuses first
appearance at the Vertebrates ones and the Invertebrates. Invertebrates with
air breathing first fossils, arachnida (oldest known, a trigonotarbide gone
back to 414 with pulmonary respiration - Petrunkevitch 1960), marine scorpions
(higher Silurian Palaeophonus) (Moret 1966), (Theobald, Gama 1969), (Grassé
1993), (Taylor and Taylor 1993); myriapoda. Swim bladder acquisition at
Actinopterygia (higher Silurian) which will become a pulmonary at Dipnoi in
Devonian (Babin 1991), (Grassé 1992).
In Devonian, with a PO2 P.A.L. rate carried with
0,68/0,74, the air various modes, cutaneous, pulmonary, trachean, mixed
breathing simultaneous diversification, become possible. " Explosion
", starting from Devonian, of air breathing in the metazoa groups majority
and particularly at the Arthropoda and the Vertebrates (Turquier 1994). Air
breathing develops at the same time on earth and in the aquatic environments.
In the Arthropoda, at Chelicerata as at Antennata, 4 classes out of six are
adapted to air breathing: 1) Arachnida 2) Shellfishes 3) Myriapoda 4) Insects.
In the Vertebrates sub-kingdom, in 2 classes,
organisms will develop with a mixed breathing (gills, cutaneous and pulmonary)
in Devonian: 1) Fishes 2) Amphibia. The 3 other classes, with entirely air
breathing, will appear later, when the atmospheric PO2 P.A.L. rate increases
again.
PO2 P.A.L 0,93 - 360 to 295 (Carboniferous): Trachean and pulmonary
respiratory possibilities blooming - Among Amniotes with entirely pulmonary
breathing, a Vertebrates class appearance, the Reptiles. Among the
Invertebrates, Pterygota Insects with trachean breathing rise. In the Molluscs,
terrestrial pulmonary Gastropods emergence with pulmonary respiration which
will develop until the Present one.
PO2 P.A.L. 1 - 295 - Present (Permian, Mesozoic, Cenozoic):
Complete present air respiratory possibilities - "superior"
Vertebrates chronological emergence, according to their requirements level out
of O2: Mammals at higher Triassic (Rhetian), pulmonary respiration with intense
bronchial and alveolar ramifications, Birds at superior Jurassic
(Archaeopteryx), complexe bronchial system and air bags. Air breathing, more
powerful at these homeotherm amniote Vertebrates, is in connection with their
needs more significant than at poikilotherm amniote Vertebrates (Reptiles)
appeared at Carboniferous.
3)
Arguments a contrario
a) Taxa with air or mixed breathing phyla seniority and late
emergence
The probabilistic correlation, between the PO2
P.A.L. thresholds and biological and respiratory processes that they make
possible, and the taxa concomitant or posterior appearance using these new
processes is clearly highlighted in the preceding table. This correlation
between the PO2 P.A.L. evolution, that of the biological processes and the
respiratory systems that it allows, and the animal evolution, is corroborated
by the taxa with air breathing examination. If the watery Vertebrates
appearance possible in Cambrian and is proven in Ordovician (Ostracodermi), the
forms with mixed or air breathing (Fishes, Amphibia, Reptiles, Mammals and
Birds) are known only from Devonian and later on (0,67 to 1 PO2 P.A.L.).
Concerning the Invertebrates, the correlation is also obvious. The sub-kingdom
adapted best to air breathing, that of the Arthropoda, is known in the aquatic
environment since basal Cambrian (Trilobites, Crustacean Ostracods,
Malacostraceous - Cambrian Ceratiocaris and Hymenocaris) (Theobald, Gama 1969),
whereas 4 classes out of 6 are adapted to air breathing only since Devonian
(Arachnida, Isopoda Crustaceous, Myriapoda and Insects). One does not count air
breathing Annelida (Oligochaeta or Achaeta) (Theobald, Gama 1969) that since
Mesozoic whereas the sub-kingdom exists since the Precambrian one (Ediacara
fauna) (Cloud, Glaessner 1982). Among Molluscs, the Gastropods class is known
since lower Cambrian (Amphigastropoda, Tryblidiata, Bellerophontata), whereas
pulmonary Gastropods, with air breathing, are it only since Devonian (marine)
or the Carboniferous (terrestrial) (Theobald, Gama 1969).
b) Taxa with mixed breathing in the intertidal mediums
The intertidal systems exist since the Precambrian
and the Gastropods and Shellfishes classes with watery breathing since lower
Cambrian. However, the intertidal organisms with mixed, watery and/or air
breathing, are listed only since Devonian and later on (Molluscs:
Prosobranchia, Opisthobranchia and Pulmonary Gastropods; Arthropoda: Decapoda
Paguroide Shellfishes of Mesozoic) (Theobald, Gama 1969), (Turquier 1994).
Thus, even in this very particular ecological system, only a significant
increase in the PO2 P.A.L. rate at Devonian allows the release, starting from a
certain threshold, by the probabilities, the emergence of the taxa with air
breathing.
V
Conclusion
The examination of the biological evolution,
concomitant with the increase in PO2 P.A.L., during various geological times,
enabled us to note, thanks to many facts, the probabilistic model explanatory
and predictive capacity.
This model highlighted chronological emergence of
certain groups of animals, from what we proposed to call the thresholds rule:
this rule expresses the relation which exists between the biological process
possibility permitted by the PO2 P.A.L. rate and the organisms probabilistic
reaction to the oxygen stimulus.
At the superior Archaean, the oxygen absence in the
atmosphere authorizes only the anaerobic procaryotic organisms existence.
Later, the beginning of the presence of a small atmospheric oxygen quantity
(0,002 to 0,003), makes possible aerobiosis with the emergence of obligatory or
optional aerobic procaryotic organisms.
The 0,01 PO2 P.A.L rate, reached towards 2 B.Y.,
seems necessary to the aerobic eucaryote cells operation, which appear roughly
at that moment.
The 0,07 to 0,10 PO2 P.A.L. rate, reached towards
565 M.A., necessary to the soft body organisms construction (conditioned by the
collagen fibres, sterols, fatty acids, and muscles development) then
exoskeletons organisms (conditioned by the biomineralization threshold)
corresponds to the vendian fauna appearance followed by the "cambrian
explosion".
The PO2 P.A.L. rate reached at the Silurian end
(0,408 B.Y.), > 0.13 < 0.67, seem to start to allow absorption, by the
organisms, until there strictly watery, of the atmosphere oxygen (marine
Scorpions). In Devonian (0,408 to 0,360 B.Y.), where the PO2 P.A.L. rate
reaches approximately the 2/3 of the present rate, air breathing can open out
in 2 principal respiratory systems: the pulmonary system at the Vertebrates
(still mixed, watery and air breathing at Fishes - Dipnoi - and the Amphibia -
Stegocephalia -) and the trachean system in the Invertebrates (particularly at
the Arthropoda, 4 classes out of 6). These 2 great systems can be combined
(trachean - Arachnida pulmonary breathing) or be reversed (Pulmonary Gastropods
pulmonary at Carboniferous).
From Devonian dates rise from the air breathing
organisms, which will develop until the Present one, parallel to the increase
in the PO2 P.A.L rate which grows from 0,67 to 1. The organisms have the
present pulmonary and trachean posssibilities. The Vertebrates with entirely
air breathing emerge, in their increasing oxygen consumption chronological
order (Reptiles to the terminal Carboniferous, Mammals at higher Triassic,
Birds at the superior Jurassic). The Invertebrates, with trachean breathing,
open out from Carboniferous (Insects, which represent 80 % of the present
animal species). In the same way, pulmonary terrestrial Gastropods, listed from
Carboniferous, develop until our days. From Annelida, Oligochaeta (Lombrics),
with cutaneous air breathing, would date from the superior Jurassic. In the
same way, from Hirudinea would date from the Eocene. In the decapoda
Shellfishes, Paguridae, with mixed breathing, are represented from the
Cretaceous.
The respiratory systems development chronology,
aerobic, watery (cutaneous and gills) then air (cutaneous, trachean and
pulmonary) among protists (eucaryote cells) then the metazoa (vendian fauna,
Vertebrates and Invertebrates with air breathing) cannot be regarded as fortuitous.
As it could be noted in the preceding chapters, it is parallel and concomitant
with the PO2 P.A.L. evolution. It concerns, simultaneously, most of the taxa.
One can thus consider, rightly, that the emergence of the various respiratory
systems common denominator is the PO2 P.A.L. rate. Maybe, probably, around 0,01
for the breathing protists, approximately 0,07 for cutaneous watery breathing,
from 0,10 to 0,16 for gill breathing and probably towards 0,67 for air
breathing.
In conclusion, the whole of the preceding facts
validates our probabilistic interaction model third application between the
environment parameters evolution and the animal taxa evolution. The molecular
oxygen free rate PO2 P.A.L. is one of these parameters. It can be regarded as a
stimulus to which the organisms react. Parallel to its increase, in a
probabilistic way, the biological (procaryotic cells, eucaryote cells,
protozoa, metazoa, exoskeletons and endoskeletons) and respiratory (cutaneous,
gills, pulmonary and trachean) systems are evolving.
Next : X General conclusions
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