Transcript The Major Transitions in Evolution

Towards and Extended
Evolutionary Synthesis
Eörs Szathmáry
München
Collegium Budapest
Eötvös University
What I am omitting
• VERY mathematical aspects, such as
– Adaptive dynamics
– Statistical mechanics as applied to multilocus
and quantitative genetics
• Evo-Devo (too much for this talk)
• Most of epigenetic inheritance
• Astrobiology (so far only hunches)
J. Huxley (1942) Evolution: the
Modern Synthesis
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Can hardly be modern
Is it wrong?
No, BUT
It is INCOMPLETE
Units of evolution
1. multiplication
2. heredity
3. variability
Some hereditary traits affect
survival and/or fertility
Von Kiedrowski’s replicator
Autocatalytic peptide networks
Chemical evolution was a race
between tar formation and life
formation
Chemical networks
Life
Tar
What fraction of planets would end
up with just tar?
The major transitions (1995)
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* These transitions are regarded to be ‘difficult’
Molecular hypercycle (Eigen,
1971)
autocatalysis
heterocatalytic
aid
Parasites in the hypercycle (JMS)
short circuit
parasite
The stochastic corrector model
for compartmentation
Szathmáry, E. &
Demeter L. (1987)
Group selection of early
replicators and the
origin of life. J. theor
Biol. 128, 463-486.
Grey, D., Hutson, V. &
Szathmáry, E. (1995) A
re-examination of the
stochastic corrector
model. Proc. R. Soc.
Lond. B 262, 29-35.
The structure of the genetic code
• Amino acids in
the same
column of the
genetic code
are more
related to each
other physicochemically
The RNA world may have preceded
the RNA-protein world
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Easy optimisation (with limits)
Many artifical ribozymes (BUT no replicase)
Coenzymes
Ribozyme doing peptidyl transfer during
protein synthesis in ribosomes
• Amino acyl-tRNA synthetases are NOT the
most ancient proteins
• 20 residues are better than 4 in catalysis
Amino acid binding RNA aptamers
(Yarus, 2009)
Why is language so interesting?
• Because everybody knows that only we talk
• …although other animals may understand a
number of words
• Language makes long-term cumulative
cultural evolution possible
• A novel type of inheritance system with
showing “unlimited hereditary” potential
What is so special about human
language?
• Basically, it is the fact that we make
sentences out of words, using grammar
• Languages are translatable into one another
with good efficiency
• Some capacity for language acquisition
seems to be innate
Recuerdos de mi vida (Cajal, 1917,
pp. 345–350)
“At that time, the generally accepted idea that the
differences between the brain of [non-human]
mammals (cat, dog, monkey, etc.) and that of
man are only quantitative, seemed to me unlikely
and even a little offensive to human dignity. . .
but do not articulate language, the capability of
abstraction, the ability to create concepts, and,
finally, the art of inventing ingenious
instruments. . .
seem to indicate (even admitting fundamental
structural correspondences with the animals) the
existence of original resources, of something
qualitatively new which justifies the
psychological nobility of Homo sapiens?. . . ’’.
Understanding language
evolution is difficult
Challenges: a simple experiment
(Hauser & Fitch)
• Habituation experiments
• Finite state grammar
(AB)n is recognizable by
tamarins
• Phrase structure grammar
AnBn is NOT.
• Human students
recognize both
Recursive syntactic pattern learning
in birds?
• European starlings (Sturnus vulgaris) accurately
recognize recursive syntactic patterns
• They are able to exlude agrammatical forms
• Centre-embedding is not uniquely human?
An unpleasant problem
Counting
Real embedding
Evolution OF the brain
The coevolutionary wheel
Intermediate
capacities: e.g.
analogical
reasoning
A neglected process?
• "A wonderful exploration of this strangely neglected topic,
opening new vistas on how organisms - including humans
- construct ecological niches over evolutionary time…. I
think this book is a 'must read'." Robert May
Niche construction
• Confounded vocabulary?
• More than the extended phenotype?
• Niche construction is the process in which
an organism alters its own (or other
species') environment, often but not always
in a manner that increases its chances of
survival.
Niche construction II
• Not only does the environment cause changes in
species through selection, but species also cause
changes in their environment through niche
construction
• The effect of niche construction may be especially
pronounced in situations where the alterations
persist for several generations, introducing .
Organisms inherit two legacies from their
ancestors, genes and a modified environment.
The „traditional view”
The revised view