Events Detail

Speaker:
Kevin Lala

Kevin Lala, Professor, Biology, University of St Andrews

The future of inheritance
Until recently, for biologists, the term ‘inheritance’ has been almost completely synonymous with genetic transmission. However, the last decades have witnessed an explosion of interest in animal culture, whereby numerous species of vertebrates and some invertebrates acquire adaptive knowledge and skills from conspecifics and heterospecifics, which inform collective decision-making. Supplementing that already replete and challenging literature is an avalanche of investigations into other disparate aspects of extra-genetic inheritance, including epigenetics, where the transmission of epigenetic marks across generations has quite literally ripped up the rule books as to what is biologically possible, and inherited bacteria and other symbionts that collectively make up the inherited microbiome. This literature has generated considerable excitement and debate, but little consensus. Biologists know there is more to inheritance than genes, but how much more, and how important other forms of inheritance are to evolutionary adaptation, remains a matter of dispute. In truth, extra-genetic inheritance has been shrouded in a murky unintelligibility for over a century. Its abstruseness results from a combination of nightmarish complexity and mechanistic diversity which, compared to Mendelian genetics, can leave it looking chaotic, transient, and idiosyncratic.  Here I suggest that extra-genetic inheritance does an important job in evolution, but that job is, in the main, distinct from that of genetic inheritance. Understanding this role requires thinking differently about the processes of adaptation and the capacity to evolve, moving away from a gene-centric perspective. Drawing on examples of cultural inheritance in animals, epigenetic inheritance in animals and plants, and the inherited microbiome, I will illustrate how extra-genetic inheritance is best regarded as an essential tool for short-term, rapid-response adaptation. Inheritance is not a single discrete package of genes and other cytoplasmic resources, but a time-distributed developmental process that primarily functions to match descendants to anticipated conditions. Like-begets-like parent-offspring correspondences are nothing more than a side effect of this adaptive reconstruction: the ultimate function of heredity is not stable transmission but accurate prediction.