Mi öröklődik a géneken kívül? Szathmáry Eörs Eötvös University Collegium Budapest

Units of evolution hereditary traits affecting survival and/or reproduction 1.multiplication 2.heredity 3.variation

The formose ‘reaction’ formaldehyde glycolaldehyde autocatalysis Butlerow, 1861

The reductive citric acid cycle

Von Kiedrowski’s replicator

Peptide replicator networks

Classification of replicators Limited heredity Unlimited heredity Holisticformose ModularVon Kiedrowski genes Limited(# of individuals)  (# of types) Unlimited(# of individuals) << (# of types)

King (1980): evolution of the coenzymes He looked at the metabolic maps then Coenzymes looked auto- and cross-catalytic BUT the situation is slightly more complicated The idea nicely links to the assumed primitive ancestry of coenzymes (related to the idea of the RNA world)

An autocatalytic cycle in the given environment

Although A is autocatalytic, it is not strictly needed Dependent on the environment!

Autocatalysis of the pair (A, B) is more complicated, but easy to see

If this is big, you may not realize the autocatalysts

The basic question Could one kick-start metabolism just with external molecules and macromolecules (genes an enzymes)? Influx  buildup of metabolism?

Metabolic networks

Membrane heredity

Principle of membrane heredity

Prions

Strain-specific prion propagation

Yeast and fungal amyloid prions

Epigenetic inheritance 1.Structural inheritance (e.g. cortical inheritance in ciliates) 2.Autocatalytic gene activity 3.Chromatin marking (e.g. methylation)

Genetic and epigenetics

Regulation of gene expression by constitutive expression of a protein After division the state is inherited because enough protein is around

Stable and unstable epigenetic markings

Inheritance of DNA methylation patterns

Linaria flower inheritance

Linaria (gyújtoványfű) A naturally occurring mutant of Linaria vulgaris, originally described more than 250 years ago by Linnaeus, in which the fundamental symmetry of the flower is changed from bilateral to radial. The mutant carries a defect in Lcyc, a homologue of the cycloidea gene which controls dorsoventral asymmetry in Antirrhinum. The Lcyc gene is extensively methylated and transcriptionally silent in the mutant. This modification is heritable and co-segregates with the mutant phenotype. Occasionally the mutant reverts phenotypically during somatic development, correlating with demethylation of Lcyc and restoration of gene expression. It is surprising that the first natural morphological mutant to be characterized should trace to methylation, given the rarity of this mutational mechanism in the laboratory. This indicates that epigenetic mutations may play a more significant role in evolution than has hitherto been suspected.

Somatic instability of peloric plants

Types of transmitted variation

Language is not Weismannian germ soma germDNA protein DNA protein germ Neural representation sentence Neural representation

Chimpanzee culture Each chimpanzee community has its own unique array of traditions that together constitute the local ‘culture’. ‘Customary’ acts are those typical in the community, ‘habitual’ ones are less common but consistent with social transmission, and ‘absent’ acts are those missing with no apparent straightforward environmental explanation. Traditions are defined as behaviour patterns that are customary or habitual in at least one site but absent elsewhere. Transmission is attributed to social learning on the basis of a complex of circumstantial evidence, ranging from intense observation by juveniles to distributions inconsistent with alternative explanations.

The cultures of wild chimpanzees

The different social conventions of neighbours: the grooming hand-clasp

Tool-set for harvesting termites

Selective copying

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

Design features of language Compositionality (meaning dependent on how parts are combined) Recursion (phrases within phrases) Symbolicism (versus icons and indices) Cultural transmission (rather than genetic) SYMBOLIC REFERENCE and SYNTAX

Three interwoven processes Note the different time-scales involved Cultural transmission: language transmits itself as well as other things, has its own dynamics