Future Darwinism- The Lamarckian Landscape

There is an elephant in the Darwinian room and that elephant is named ‘Lamarck’. The mechanisms of traditional evolutionary Darwinism are now being rewritten and in the process raise again the spectre of the Lamarckian paradigm.

This alternate route to evolutionary selection, initially pioneered by Jean-Baptiste Lamarck in 1800, has much to offer science and civilisation.

Standard Darwinism places its adaptive bets on two processes- the recombination and mutation of genetic information. But the time taken to achieve adaptation in times of rapid change, such as today’s global warming, is just too slow to enable organisms to survive.

Nature has therefore taken a shortcut.

The search for the full majesty of the processes guiding evolution has dramatically advanced over the last decade, with an emerging understanding of the multilayered controls of gene expression and direct feedback from the wider environment. These complex intertwined multi-layered processes can be best understood in terms of networked patterns, invoking information, systems and graph theory. They have now exposed a whole new post Darwinian roadmap for researchers.

Accelerated adaptation is quite readily accepted in behavioural and cultural evolution. It is recognised that changes in the social landscape can provide almost immediate feedback to humans and institutions allowing them to flexibly and efficiently alter their responses to new situations.

The process of a frog needing to adapt to temperature rises in its traditional habitat, caused by global warming and GM needing to respond to consumer pressure for more fuel efficient cars, are in fact identical. They both depend on the system sensing information signals from its environment- natural or social- and then modifying its behaviour to best fit the environment’s demands; maximising the odds of its survival.

This is similar to the Lamarck’s thesis, which suggested that direct feedback from the environment could play an active role in altering an animal’s future genetic traits. But until recently the mechanisms enabling this type of fast track response were neither understood nor accepted by mainstream biologists.

The process of natural system evolution has evolved several biological mechanisms for fast tracking itself- via transposon editing and epigenetic inheritance.

Transposons are short sequences of DNA that contain their own promoters enabling them to position next to a host gene and alter its activity. This provides genomes with the capability to engineer themselves by moving around, cutting and pasting themselves into different parts of the genome and allowing evolution to proceed faster than by random mutation.

There are 13,000 human genes associated with transposons, including rapidly evolving genes such as those responsible for the immune system. Transposons can alter the course of evolution by altering the expression of genes and also the structure of proteins. For example, cells can produce either the altered protein or a normal backup, allowing evolutionary experimentation by shuffling the building blocks around.

The host organism is forced to build immunity to transposons in a competitive cycle, which drives increasing complexity. The spin-off may have been the evolution of the DNA methylation process to suppress transposons but also allow them to silence their own genes. This allows either maternal or paternal genes to be turned off in the developing embryo in a process known as imprinting. It also ensures that only one of two x chromosomes in females is active.

Epigenetic inheritance through gene silencing, provides a way for populations of animals to quickly adapt to their environment, creating a fast track supplement to Darwinian selection. There is also now evidence that epigenetic changes can pass from one generation of mammals to the next. Two genes in mice had been methylated and the offspring also had both genes methylated and switched off. A gene can therefore be defined by both its DNA sequence and epigenetic instructions or degree of methylation.

This also changes the debate relating to the insulation of sperm and egg genes from their external environment, which are not as isolated as previously thought. Normally the slate is wiped clean during egg and sperm formation and all epigenetic changes are reset. However it is possible that the methylation pattern on some genes does not get reset, so that the effect can be permanent. This explains how environmental impacts of cancer-causing agents such as pesticides can be passed on to three or four future generations.

This new Lamackian landscape is likely to be of profound significance to the understanding of life and the science of evolution; leading for example to the development of more powerful computer evolutionary algorithms and to the design of systems capable of self-reproduction and self-programming; delivering true artificial life and intelligence.

In the past biologists who proposed alternatives to traditional Darwinian mutation such as Paul Kammerer in the 1920s, were marked as frauds and heretics. Now it is seen that the two approaches to environmental adaptation and inheritance are in fact complementary, expanding on the power of Darwin’s original theory.

It is also a timely reminder, particularly in the year of Darwin, that our understanding of the mysteries of life are far from complete and that the creative research outsider still has much to offer.