The evolution of episodic memory

TLDR

A prevailing view holds that episodic memory emerged recently in humans and lacks a Darwinian evolutionary basis. The authors review evidence for a long evolutionary history of episodic memory, propose a shared neural circuit across mammals and birds, and outline potential emergence time points. They discuss the advantages of episodic memory and species‑specific divergences built upon a fundamental memory architecture. They find that core episodic memory features and key brain regions exist in mammals and birds, implying a shared neural ancestry rather than convergent evolution.

Abstract

One prominent view holds that episodic memory emerged recently in humans and lacks a “(neo)Darwinian evolution” [Tulving E (2002) Annu Rev Psychol 53:1–25]. Here, we review evidence supporting the alternative perspective that episodic memory has a long evolutionary history. We show that fundamental features of episodic memory capacity are present in mammals and birds and that the major brain regions responsible for episodic memory in humans have anatomical and functional homologs in other species. We propose that episodic memory capacity depends on a fundamental neural circuit that is similar across mammalian and avian species, suggesting that protoepisodic memory systems exist across amniotes and, possibly, all vertebrates. The implication is that episodic memory in diverse species may primarily be due to a shared underlying neural ancestry, rather than the result of evolutionary convergence. We also discuss potential advantages that episodic memory may offer, as well as species-specific divergences that have developed on top of the fundamental episodic memory architecture. We conclude by identifying possible time points for the emergence of episodic memory in evolution, to help guide further research in this area.