Predation and the origin of neurones

Area of Science:

• Evolutionary Biology
• Neuroscience
• Paleontology

Background:

• Spiking neurons, fundamental to animal nervous systems, exhibit conserved designs across diverse species.
• Understanding the evolutionary pressures that shaped these neurons is key to interpreting their modern functions.

Purpose of the Study:

• To investigate the timeline and selective forces behind the evolution of spiking neurons in animals.
• To integrate fossil, ecological, and molecular data for a comprehensive evolutionary analysis.

Main Methods:

• Review of fossil records to establish timelines for nervous system and predation emergence.
• Analysis of ecological data on early animal feeding strategies.
• Examination of genetic evidence to determine the timing of nervous system evolution relative to major animal splits.

Main Results:

• Fossil evidence suggests nervous systems evolved around 550 million years ago, coinciding with the advent of animal-on-animal predation.
• Early animals (pre-550 MYa) were likely filter feeders or grazers, utilizing simpler mechanisms than spiking neurons.
• Genetic data indicates nervous systems evolved before the protostome-deuterostome split, with independent evolution in cnidarians and bilaterians being a possibility.

Conclusions:

• Animals likely evolved spiking neurons shortly after the emergence of predation.
• The earliest sensory neurons may have functioned as proximity detectors, triggering essential escape or attack responses.