PART 1 OF 3: INTRODUCTION & MOLECULAR PATHWAYS (HALLMARKS 1-4)

A Comprehensive Research Review

Author: Alice Frolov

Field: Aging Biology, Molecular Biology, Biotechnology

Date: February 2026

Document Type: Comprehensive Scientific Review

TABLE OF CONTENTS - PART 1

I. INTRODUCTION

1.1 Defining Aging: From Phenomenology to Molecular Mechanisms

1.2 The Hallmarks Framework: Organizing Principles

1.3 Aging as a Tractable Biological Problem

1.4 From Lifespan Extension to Healthspan Extension

1.5 Epigenetic Clocks: Quantifying Biological Age

1.6 Scope and Objectives of This Review

II. MOLECULAR PATHWAYS OF AGING

II.A GENOMIC INSTABILITY

2.1 Sources of DNA Damage

2.2 DNA Repair Mechanisms and Their Age-Related Decline

2.3 Accumulation of Somatic Mutations