Determining the dominant animal on Earth is not a straightforward question, as there are many ways to define “dominance” when it comes to animals. However, if we look at measures like biomass, number of individuals, and impact on ecosystems, a clear frontrunner emerges: humans.
What does it mean for an animal to be “dominant”?
There are a few key factors we can look at to determine which animal is dominant on Earth:
- Biomass – The total weight or mass of a species across its global population. The animal with the highest total biomass could be considered the most dominant.
- Number of individuals – The species with the highest number of individual organisms could also be deemed the most dominant.
- Impact on ecosystems – An animal that has an outsized influence on other species and shapes ecosystems could be seen as dominant.
- Range/territory – A species with the widest global distribution and largest geographic range could be considered dominant.
- Intelligence/cognition – An animal with high intelligence and advanced cognitive abilities could potentially leverage those traits for dominance.
There are good arguments for different species when looking at each factor. But one species stands out when we consider them together: humans.
By biomass, humans dominate
According to estimates, the total global biomass of humans is approximately 287 million tons. This far exceeds that of any other animal species on land or in the sea. The animal kingdom with the next highest biomass is domestic poultry (chickens) at around 175 million tons.
Here are estimated global biomass figures for some major animal groups:
|Animal||Estimated global biomass (million tons)|
Based on pure biomass which takes into account the combined weight of all individuals, humans dominate by a significant margin over all other animal species.
Humans number in the billions
There are approximately 7.9 billion humans on Earth as of 2021. This gives us the highest global population of all terrestrial vertebrate species.
No other mammal even comes close in terms of number of individuals. The animal with the next largest population is likely the domestic cow, with around 1 billion currently alive around the world.
Here’s how human numbers compare to some major mammal species worldwide:
|Species||Estimated global population|
No single insect species rivals human numbers either – even abundant insects like ants likely only have populations in the trillions, still well below the multiple trillions of humans.
Humans have an outsized ecological impact
Humans have played a major role in shaping ecosystems across the planet, having significant and often detrimental impacts on many other plant and animal species.
Some examples of substantial human ecological impacts include:
- Conversion of natural habitats like forests, grasslands, and wetlands into agricultural land and cities. Over 50% of the Earth’s land surface has been converted or substantially modified by human activity.
- Overfishing of the oceans, leading to crashes in populations of many marine species.
- Hunting and poaching driving declines in large mammals, predators, and other wildlife. Many megafauna extinctions have been attributed to early human hunters.
- Alteration of global biogeochemical cycles like the carbon, nitrogen, and phosphorus cycles through activities like fossil fuel burning and fertilizer use.
- Spread of invasive species by human travel and trade that outcompete and displace native plants and animals.
- Climate change driven largely by greenhouse gas emissions from human activities like energy production.
No other contemporary species has matched the sheer scale and impact of human ecological change across the planet.
The human range spans the entire globe
The only terrestrial animal found on every continent, humans have managed to expand our geographical range to encompass the entire planet. Even in remote areas like Antarctica, permanent and seasonal research stations showcase a persistent human presence.
While some species like brown rats have spread to most continents and remote islands via human travel and trade, no other wild animal species has achieved truly global distribution without human assistance. Even highly mobile species like some bird and fish populations are localized and restricted compared to the planetary-scale spread of Homo sapiens.
Our adaptability as a species has allowed humans to inhabit diverse environments from Arctic tundra to tropical rainforests, making the human range the widest of any mammalian organism.
Advanced cognition gives humans unique dominance
While intelligence and cognition are difficult concepts to quantify, humans possess mental capabilities like complex language, abstract thought, self-awareness, and problem-solving skills that are unparalleled in the animal world.
Our sophisticated brains have enabled innovations like agriculture, industry, medicine and technology that provide humans with unmatched abilities to manipulate and thrive in our environments. No other animal species exhibits culture, social structure, or knowledge transmission on the scale of human civilizations.
Our cognitive gifts equip humans with the capacity to dramatically shape not just ecosystems, but the entire planet – for good or for ill. When considering the totality of human thought and ingenuity, we stand apart from all other life on Earth.
Examining factors like biomass, population, ecological impact, distribution, and intelligence paints a clear picture of humans as the dominant animal species on Earth today. Our massive numbers, global spread, and outsized influence on nature speak to the unprecedented dominance of Homo sapiens on the planet.
While humans may not be the strongest, fastest, or largest animals, our cognitive gifts and adaptability have enabled us to thrive and assume a controlling role across Earth. For better or worse, the planet is now in the age of the human animal. Our future dominance will depend on learning to wield our influence wisely as responsible stewards of the world we inhabit and share with all life on Earth.