Aim & scope of Malthusian relativity

Malthusian relativity is a theory of evolution where the life history diversity of the major lifeforms is naturally selected from the origin of replicating molecules.

The theory follows the Darwinian principle that the naturally selected life history of a descendant is naturally selected from the naturally selected life history of its ancestor. This develops selection beyond the life history theory of the population genetic synthesis that selects species---not from ancestors and nor further towards descendants but---only locally towards measured peaks in a fitness landscape.

To select descendants further than ancestors we include the intra-population ecology of interactive competition, changing our natural selection concept from 'a selection increase in average fitness' to 'a selection change in relative fitness'.

Intra-population interactive competition is commonly observed, and by including it, Malthusian relativity develops natural selection theory from its origin on September 28, 1838. Here, Darwin (1887) read Malthus (1798) and realised that 'a struggle for existence' that is 'most severe between the individuals of the same species' 'follows from the high rate at which all organic beings tend to increase' (Darwin, 1859).

Malthusian relativity shows how this density-dependent interactive competition selects necessary and sufficient changes in relative fitness to select the life histories of the major lifeforms from net energy selected for replication. The selected net energy generates population growth and interactive competition that reallocation-selects the increase in replication-energy into larger, more cooperatively organised slower replicating units. This predicts an essentially inevitable evolution of large multicellular organisms with inter-specific allometries and sexual reproduction by a diploid genome with fair meiosis.

The original 1997 version of Malthusian relativity covered the natural selection transition from small asexual self-replicators to large sexually reproducing animals with body mass allometries, and eusocial colonies as special cases. Twenty years later I included the natural selection of metabolism, explaining evolutionary transitions from replicating molecules over prokaryote and eukaryote like unicells to multicellular animals. By 2024, the framework was used to estimate life histories and population dynamics across the birds and mammals of the world.

The mrLife.org webpage describes the essential concepts, predictions, and evidence. It includes free downloads of the original scientific work and allows for population dynamic simulations of birds and mammals.