29.05.2015 - 14:25
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Information in Evolution (Michael Lachmann)

The group leader Michael Lachmann has moved to the Santa Fe Institute:

The main interest of the group is understanding evolutionary phenomena associated with evolutionary transitions of the selected units. Examples for such transitions include the evolution of multicellularity, the evolution of eusocial groups, such as ant and wasp colonies, the evolution of human culture, and the origin of Darwinian selection. Such transitions raise very interesting evolutionary questions, and we try to address some of them.

Currently, we are working on the following directions:

Evolution of differentiation

Multicellular organisms follow a developmental plan leading them from the fertilized egg to an adult organism. Different cells in the adult can perform different functions, and express different genes. These are the different cell types that are part of the various tissues of the multicellular organism.

Some of the questions that interst us are:

  • How does differentiation evolve?
  • How did the control of differentiation evolve when multicellulars evolved?
  • What are cell-types, and how does gene-expression in the various cell-types change over evolutionary times?
Evolution of ant colony behavior

Some of the evolutionary processes that occur at the evolution of eusociality are similar to the processes that occur in the evolution of multicellularity. In the evolution of eusociality the main selective drives switched from functions that concern the behavior of single organisms, e.g. single wasps, to functions that concern the coordination of the whole colony. Similarly in the evolution of multicellularity selection switched from selection of functions that concern the single cells to functions that concern the functioning of a whole multicellular colony. There are some important differences, though. One is that in an ant colony the different ants are not genetically identical, whereas in an animal most of the cells contain the same genes. A second difference is that in eusocial colonies the units (i.e ants, wasps, etc) are free to move around. No long-term physical connections between the units exist. because of this, control of the behavior of the colony has to occur through different means.

Evolution of meaning and deception in signalling systems

Many organisms use signals. These signals influence their behavior, or influences the behavior of other organisms. When a signal is employed between two organisms, one might ask if the benefit of the transaction is to the sender or the receiver. Responding to a signal opens up the possibility that the receiver will be manipulated by the sender. Is such manipulation equivalent to deception? With human language two new concepts appear: truth and meaning. How do these evolve? When in the evolution of signalling did truth and meaning evolve?

Rates of information accumulation during evolution

The genome of an organism contains information. This information is used by the organism in order to construct a phenotype that is adapted to the environment. It is also used by scientists to reconstruct the organism's evolutionary history. How does the information get into the genome? What is the relation between selective pressures, uncertainty that the organism might experience, signals that the organism might give to others, and that the organism might receive from others?