How does evolution by natural selection work?

Introduction

Evolution by natural selection is a fundamental concept in biology that explains how species adapt and change over time. This process involves the differential survival and reproduction of individuals due to differences in phenotype, which are often influenced by genetic variations. The following synthesis presents key insights from multiple research papers on how natural selection operates and its implications for evolution.

Key Insights

Genetic Variation and Mutation:
- Mutations are not entirely random; intrinsic variations in genetic change can be influenced by natural selection, making some mutations more probable and potentially favorable.
- The probability of beneficial mutations occurring is a critical factor in the rate of evolution, with natural selection acting as a mechanism to transfer environmental information to genetic storage.
Adaptive Evolution:
- Adaptive changes can occur without the obligatory role of natural selection through mechanisms like plastic adaptive changes followed by genetic changes, making the transformation irreversible.
- In cancer biology, natural selection explains the adaptation and evolution of tumor cells, highlighting the role of selection in both somatic and organismal evolution.
Natural Selection in Natural Populations:
- Direct demonstrations of natural selection in various animals and plants show that selection can be strong and is a significant component of evolution, although it primarily explains the change in frequencies of variants rather than their origins.
- Soft selection, where survival and reproduction depend on population density, genotype, and genotype frequencies, plays a crucial role in how organisms adapt to natural environments.
Ecological Mechanisms:
- Evolutionary processes are influenced by local ecological dynamics, such as resource availability and predator-prey interactions, which affect the fitness and survival of different genotypes.

Conclusion

Natural selection is a complex and multifaceted process that drives evolution by favoring certain genetic variations over others. While mutations and genetic changes are fundamental to this process, the probability and type of these changes can be influenced by natural selection. Adaptive evolution can occur through various mechanisms, including those independent of natural selection. In natural populations, selection can be strong and is influenced by ecological factors and population dynamics. Overall, natural selection remains a central mechanism in understanding how species evolve and adapt over time.

How does evolution by natural selection work?

Summary

Introduction

Key Insights

Conclusion

Sources and full results

Natural selection and the emergence of a mutation phenotype: an update of the evolutionary synthesis considering mechanisms that affect genome variation.

Natural selection can make potentially beneficial mutations more likely than random ones, improving survival chances in various organisms.

Adaptive evolution without natural selection

This paper presents a mechanism of evolution that ensures adaptive changes without the obligatory role of natural selection, involving plastic adaptive changes followed by stochastic genetic changes, which makes the transformation irreversible.

Natural selection: an information-transmission mechanism for evolution.

Natural selection effectively transfers information from the environment to genetic storage, with a very small probability of mutating into beneficial genes in a given number of trials.

Natural Selection in Cancer Biology: From Molecular Snowflakes to Trait Hallmarks.

Adaptation through natural selection is a useful framework for understanding cancer's defining characteristics and explains why diverse pathologies share the "cancer" label and become life-threatening.

Natural selection in the wild

Natural selection is a significant component of evolution, with a broad range of observed magnitudes and a strong overlap with artificial selection.

Hard and Soft Selection Revisited: How Evolution by Natural Selection Works in the Real World.

Soft selection, influenced by population density and genotype frequencies, plays a crucial role in shaping organisms' adaptation to natural environments and shaping both evolution and ecology.

Ecological mechanisms of evolution by natural selection: causal processes generating density-and-frequency dependent fitness.

Natural selection in local populations occurs through dynamic shifts in equilibria, with invasive species causing extinctions or reducing the survival rate of old ones.

Natural selection and evolution

Natural selection is a key mechanism for evolution, and students apply this knowledge to a laboratory investigation examining the impact of food availability on bird beak frequency.

The Genetical Theory of Natural Selection. A Complete Variorum Edition . By R. A. Fisher (edited with foreword and notes by J. H. Bennett). Oxford University Press. 1999. ISBN 0-19-850440-3. xxi+318 pages. Price £25.00.

Fisher's The Genetical Theory of Natural Selection is a crucial book on evolution, integrating transmission genetics and evolutionary theory, and remains influential in contemporary research.

Testability of the Role of Natural Selection within Theories of Population Genetics and Evolution

Natural selection plays a crucial role in both population genetics and evolution theories, but its testability in these fields remains a matter of debate.

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