Biochemical Evolution
Ibarra Jonatanh
Ouředničková Veronika
Faculty of chemistry, Brno University of Technology
Vocabulary
EN
CZ
EN
CZ
Acquire
Získat
Enabling
Umožnující
Pass on
Předat
Response
Odezva
Traits
Vlastnosti
Requiring
Požadující
Diversity
Rozmanitost
Allow
Dovolit
Vast
Obrovský
Remarkably
Pozoruhodně
Rate
Poměr
Ancestor
Předek
Increasingly
Zvýšeně
Paths
Cesty
Biological Evolution

The process by which
populations of organisms
acquire and pass on
novel traits from
generation to
generation. Its action
over large stretches of
time explains the origin
of new species and
ultimately the vast
diversity of the biological
world.
Biochemical Evolution


Chemosynthesis:
hypothesis to explain how life might
possibly have developed from nonlife.
Three stages:
1st Stage of Evolution



The initial generation
of some of key
molecules of life
(nucleic acids,
proteins,
carbohydrates, lipids)
by non-biological
processes.
The prebiotic world.
Urey-Miller experiment
1st Stage of Evolution


The Earth´s early atmosphere
was probably highly reduced,
rich in CH4, NH3, H2O, H2 +
large amounts of solar radiation
and lightning.
Urey-Miller
experiment (1950).
Prebiotic „lake“ – cold (under
0°C; clays); polymer synthesis
rate must be higher than their
hydrolysis (slow at low
temperature).
2nd Stage of Evolution


The transition from prebiotic
chemistry to replicating
systems; with the passage of
time, these systems became
increasingly sophisticated,
enabling the formation of living
cells; membrane formation.
Formation of replicating
molecules, variation and
selective pressure = beginning
of evolution.
2nd Stage of Evolution




RNA – an early replicating molecule;
some RNA molecules possess
catalytic activity, this was transferred
to proteins
RNA directed the synthesis of
proteins and still does in modern
organisms through the development
of a genetic code.
RNA lost its role as the gene to the
chemically similar but more stable
DNA
Evolution of membranes
(hydrophobic barriers) – first
unicellular organisms.
3rd Stage of Evolution

The biological evolution; energy-conversion
processes (photosynthesis) and pathways for
synthesizing the components of biopolymers from
simpler molecules; evolution of unicellular
organisms; colonies; differentiation and formation of
multicellular organisms; response to
environmental changes
3rd Stage of Evolution

The final transition was the
evolution of sensing and
signaling mechanisms that
enabled a cell to respond to
changes in its environment;
cell-cell communication
allowed the development of
more-complex organisms.
Evolutionary tree – “the tree of life”


Organisms are
remarkably uniform
at the molecular
level.
Uniformity life have
come into
existence only
once (Darwin).
Evolutionary tree – “the tree of life”


This uniformity reveals
that all organisms on
Earth have arisen from a
common ancestor
(bacteria are no direct
ancestors of higher
organisms)
Evolutionary paths from
a common ancestor to
modern organisms can
be developed and
analyzed on the basis of
biochemical information
Thank you for your attention