Evolution of human lifespan: Past, future, and present.

Area of Science:

• Evolutionary biology
• Genetics
• Gerontology

Background:

• The evolutionary theory of aging posits aging results from declining natural selection post-reproduction.
• This theory is supported by experimental data altering selection forces in populations.

Purpose of the Study:

• To review the evolutionary genetics of aging.
• To discuss the implications for human lifespan evolution and extension.

Main Methods:

• Review of evolutionary genetics principles.
• Analysis of experimental breeding studies manipulating natural selection.
• Examination of human demographic data and evolutionary trends.

Main Results:

• Aging is driven by reduced natural selection after reproduction begins.
• Experimental manipulation of selection can delay aging.
• Late-life mortality plateaus are predicted by zero natural selection.
• Human lifespan has increased due to reduced ecological vulnerability from larger brain size.

Conclusions:

• Evolutionary theory provides a robust framework for understanding aging.
• While fundamental biological barriers to lifespan extension are few, practical barriers exist.
• Future human lifespan increases may be limited by practical, rather than biological, constraints.