Related Experiment Video
Updated: Apr 30, 2026
15:00
Daily Transfers, Archiving Populations, and Measuring Fitness in the Long-Term Evolution Experiment with Escherichia coli
Published on: August 18, 2023
5.1K
Bioenergetic constraints on the evolution of complex life
1Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom.
Cold Spring Harbor Perspectives in Biology
|May 3, 2014
Summary
Eukaryotic complexity arose from endosymbiosis, where mitochondria provided energy, enabling larger genomes and unique traits. This evolutionary event overcame prokaryotic energetic constraints, driving eukaryotic evolution and diversification.
Area of Science:
- Cell biology
- Evolutionary biology
- Genomics
Background:
- All complex life is eukaryotic, originating from a single-celled ancestor.
- Prokaryotes, despite biochemical diversity, rarely evolve complex traits or large genomes.
- Eukaryotic evolution is linked to unique cellular structures and energy metabolism.
Purpose of the Study:
- To explain why prokaryotes are energetically constrained and do not evolve eukaryotic traits.
- To propose that endosymbiosis, leading to mitochondria, was the key event enabling eukaryotic complexity.
- To link the energetic advantage of mitochondria to the evolution of the nucleus, sex, and other eukaryotic innovations.
Main Methods:
- Comparative genomics analysis.
- Bioenergetic modeling.
- Origin of life research review.
Main Results:
- Prokaryotes are limited by membrane bioenergetics, hindering the evolution of large genomes and complex traits.
- Endosymbiosis between prokaryotes created mitochondria, breaking these energetic constraints.
- Mitochondria provide eukaryotes with significantly higher energy per gene (3-5 orders of magnitude) compared to prokaryotes.
- This energetic advantage facilitated the evolution of massive nuclear genomes and unique eukaryotic features.
Conclusions:
- Endosymbiosis and the resulting mitochondrial energy boost are fundamental to eukaryotic cell evolution.
- The genomic asymmetry between mitochondria and the nucleus is a direct consequence of endosymbiotic gene loss.
- The energetic liberation by mitochondria likely drove the evolution of key eukaryotic traits such as the nucleus, sexual reproduction, and aging.
Related Concept Videos
01:23Characteristics of Life
233.0K
Biology is a natural science that studies life and living organisms, including their structure, function, development, interactions, evolution, distribution, and taxonomy. The field's scope is extensive and divided into several specialized disciplines, such as anatomy, physiology, ethology, genetics, and many more. All living things share a few key traits, including cellular organization, heritable genetic material and the ability to adapt/evolve, metabolism to regulate energy needs, the...
233.0K
01:24Origin of Cellular Life
116
The origin of life on Earth is a complex and enigmatic event rooted in ancient biochemical processes and geological conditions. Experimental evidence supports the hypothesis that life began with the spontaneous formation of organic molecules such as RNA nucleotides, amino acids, and lipids under early Earth conditions. Factors like volcanic activity, intense UV radiation, and a reducing atmosphere without free oxygen likely facilitated these reactions. Hydrothermal vents on the ocean floor are...
116
01:22Entropy within the Cell
8.6K
A living cell's primary tasks of obtaining, transforming, and using energy to do work may seem simple. However, the second law of thermodynamics explains why these tasks are harder than they appear. None of the energy transfers in the universe are completely efficient. In every energy transfer, some amount of energy is lost in a form that is unusable. In most cases, this form is heat energy. Thermodynamically, heat energy is defined as the energy transferred from one system to another that...
8.6K
01:16Non-equilibrium in the Cell
4.0K
An important concept in studying metabolism and energy is that of chemical equilibrium. Most chemical reactions are reversible. They can proceed in both directions, releasing energy into their environment in one direction, and absorbing it from the environment in the other direction. The same is true for the chemical reactions involved in cell metabolism, such as the breaking down and building up of proteins into and from individual amino acids, respectively. Reactants within a closed system...
4.0K
01:24Evolution of New Traits in Microbes
199
Microorganisms evolve rapidly due to their large population sizes and short generation times, often exhibiting measurable changes within days under laboratory conditions. Natural selection acts on standing genetic variation, enabling the retention and amplification of beneficial traits that confer fitness advantages in changing environments.Adaptive Pigment Regulation in RhodobacterIn Rhodobacter, a genus of purple non-sulfur bacteria, light-harvesting pigments such as bacteriochlorophyll and...
199
02:06Conditions on Early Earth
67.0K
Around 4 billion years ago, oceans began to condense on earth while volcanic eruptions released nitrogen, carbon dioxide, methane, ammonia, and hydrogen into the primordial atmosphere. However, organisms with the characteristics of life were not initially present on earth. Scientists have used experimentation to determine how organisms evolved that could grow, reproduce, and maintain an internal environment.
67.0K