Biology Reference
In-Depth Information
Table 15.8 The history of symmetry breakings in the Universe
Concentric
circles in
Fig.
15.8
Time since
time after the
Big Bang
Temperature
(degrees)
“Mattergy” (Sect.
2.3.1
)
10
43
s
10
32
1
Radiation (i.e., energy), matter, antimatter
10
34
s
10
27
2
Radiation, matter, antimatter, quarks, gluons,
W- and Z-particles
10
10
s
10
15
3
Radiation, matter, antimatter, quarks, anti-
quarks, electrons, positrons
10
5
s
10
10
4
Radiation, electrons, positrons, protons,
neutrons, mesons
10
9
5
3 min
Radiation, electrons, H, D, He, Li
3
10
5
years
6
10
3
6
Radiation, H and other atoms
10
9
years
7
18
Radiation, atoms, galaxies
15
10
9
years
8
3
Radiation, stars, planets, DNA,
Homo sapiens
cases, the algorithmic complexity of the systems involved (defined as the number of
bits in the shortest string of symbols needed to describe an object or situation; see
Sect.
4.3
) increases, ultimately is driven by the increase in universal thermody-
Bang and biological development (and biological evolution as well) can be viewed
as examples of symmetry-breaking processes in space and time.
The cosmological symmetry breaking is generally known to be caused by the
lowering of the temperature secondary to cosmological expansion (thus reducing
the kinetic energy or momenta, i.e., velocity x mass, of particles) (see Fig.
15.12
and Table
15.8
). However, biological symmetry breakings occur at constant
temperatures (e.g., all the morphological changes shown in Fig.
15.1
occur within
a narrow range of physiological temperatures), thus without slowing down thermal
fluctuations or the Brownian motions of molecules and ions. Thus, we may associ-
ate
cosmogenesis
with “non-isothermal” or “cooling-driven” symmetry breakings
(which will decrease
kinetic
energies of particles) and
morphogenesis
with
“isothermal” or “constant temperature” symmetry breakings. In morphogenesis
what is reduced may be construed to be the average distance between cognate
binding surfaces of particles (including ions, molecules, biopolymers, and cells),
thereby affecting their
potential
energies. Just as
momenta
(i.e., kinetic energies)
and
positions
(affecting potential energies) are
complementary conjugates
in phys-
are also fundamentally related. There may be two (and only two) basic mechanisms
of symmetry breakings in the Universe.
1. The “kinetic” mechanism where increased order results from reduced
kinetic
energy
of binding partners, and
2. The “position” mechanism where increased order is caused by the reduction in
the average distances between cognate particles (accompanied by decreased
potential energies
) in two ways - (a) via “passive” Brownian motions of binding
partners and (b) via “active” translocation of binding partners driven by free
energy dissipation.
