Biologists revive Lamarck’s theory to fill gaps in Darwin’s evolution framework

More than two centuries after Jean-Baptiste Lamarck proposed that organisms could pass on traits acquired during their lifetimes, a growing body of scientific evidence is breathing new life into the long-dismissed theory. In an essay published in The Conversation on July 28, Prof Pim Edelaar, a professor of evolutionary biology at the Universidad Pablo de Olavide in Spain, argued that Lamarckism can explain evolutionary observations that standard Darwinian theory cannot.studyfinds+1

"It is time to embrace Lamarckism again," Edelaar wrote, pointing to examples ranging from worms that pass stress adaptations to their offspring to killer whales whose learned hunting behaviors shape speciation.studyfinds

Epigenetic Evidence

The revival centers on epigenetics — heritable molecular changes that do not alter the DNA sequence itself. When the worm C. elegans is exposed to viral infections, starvation, or extreme temperatures, it produces small RNA molecules that help it cope. These molecules are transferred to eggs during reproduction, meaning offspring are born with the same advantages — a process that persists across multiple generations.studyfinds

Similar effects have been documented across dozens of species. Rice plants exposed to cold develop permanent resistance through chemical tags on their genes, enabling their spread northward from tropical origins. The findings challenge the long-held assumption that epigenetic marks are always erased during reproduction.telegraph+1

Complementing, Not Replacing, Darwin

Edelaar, whose new book The Selective Organism was published this year by Oxford University Press, argues that Lamarckian inheritance operates alongside natural selection rather than contradicting it. In his framework, organisms are not merely passive targets of selection but active agents that develop certain traits in response to environmental demands.academic.oup+1

Prof Richard Buggs, a professor of evolutionary genomics at Queen Mary University of London, told The Telegraph there is "growing acceptance" within the field. "Many school textbooks are out of date on this issue," he said, noting that major conferences have discussed the evidence.telegraph

Practical Applications

Researchers say the implications extend beyond theory. Scientists in Australia are already exposing coral to heat stress in laboratories to trigger epigenetic responses that make them more resilient to warming oceans. In agriculture, exposing crops to specific soil conditions or parasites could benefit future generations of plants. And if parental behaviors influence conditions like obesity or addiction in children, prevention programs could carry benefits across generations.studyfinds