Summary: A new mathematical model reveals why different animals evolve different learning rates and memory capacities. The research, conducted by scientists at the Complexity Science Hub and Santa Fe Institute, shows that optimal learning rates follow a universal square root law relative to environmental changes, with creature size and lifespan playing crucial roles in memory development.
Journal: Proceedings of the Royal Society B: Biological Sciences, October 30, 2024, DOI: 10.1098/rspb.2024.1606
Reading time: 4 minutes
The Mathematics of Memory
In a changing world, every organism must learn and adapt to survive. But how fast should they learn? According to the new research, there’s a mathematical sweet spot for learning – too fast wastes energy on meaningless changes, too slow means falling behind crucial environmental shifts.
The researchers developed a model that predicts a universal law: an organism’s learning timescale should scale as the square root of environmental change. For example, if the environment changes twice as slowly, the optimal learning rate decreases by a factor of 1.4 (the square root of 2).
Size Matters
The study reveals that body size and lifespan significantly influence memory capabilities. For small, short-lived creatures like insects, the energy costs of learning and memory are paramount. However, for larger, longer-lived animals, these learning costs become less significant compared to their basic metabolic needs.
As CSH PostDoc Eddie Lee explains: “In contrast, larger organisms like elephants have longer memories, but exactly how long they retain information may have more to do with non-learning costs or other types of environments such as social groups which impose further cognitive demands.”
Reshaping Their World
The research also explores how some animals actively modify their environment – a process called niche construction. This ability can provide evolutionary advantages, but only if the organism can maintain exclusive benefits from these changes. The researchers use beavers as an example – while they create stable pond habitats by building dams, this advantage can diminish if other species exploit the created environment.
Glossary
- Niche construction: The process by which organisms modify their environment
- Learning timescale: The rate at which an organism processes and retains new information
- Metabolic overhead: The basic energy costs of maintaining body functions
- Square root scaling: A mathematical relationship where one variable changes as the square root of another
Reader Quiz
- Q: What happens to optimal learning rate if environmental change slows by a factor of 2?
A: It decreases by a factor of 1.4 (square root of 2) - Q: Why do small creatures like insects have well-tuned memory for their environments?
A: Because the costs of learning and memory are paramount for them - Q: What determines memory length more in larger animals like elephants?
A: Non-learning costs and social group demands - Q: What is required for niche construction to provide an evolutionary advantage?
A: The organism must be able to maintain exclusive benefits from the environmental changes
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