Earth Lost 2.5 Billion Years’ Worth of Evolutionary History in Just 130,000 Years (2024)
Humans have only been around for some 130,000 years, but a new study published in the Proceedings of the National Academy of Sciences concludes that in this relatively brief time period, we’ve managed to erase a staggering 2.5 billion years of evolutionary development by driving more than 300 mammal species into extinction.
These findings, led by paleontologist Matt Davis of Denmark’s Aarhus University, paint a grim portrait of Earth’s future—especially in light of a recent United Nations report that predicts widespread drought, flooding, extreme heat and poverty will overtake the planet if drastic action isn’t taken immediately.
As Damian Carrington reports for The Guardian, Davis and his colleagues foresee similarly dire straits for Earth’s non-human residents, many of whom are threatened by poaching, pollution and habitat destruction. Even if humans curbed these destructive actions within the next 50 years, it would take between five to seven million years for mammals to repopulate the world with the same level of biodiversity seen before the advent of modern humans and three to five million years to return to the level of biodiversity Earth currently boasts.
If this timeframe is difficult to visualize, consider a helpful piece of context provided by The Atlantic’s Ed Yong: The time needed for mammals to recover is at least ten times as long as humans have existed as a species. This makes the healing process, according to Davis, incomprehensible “on any kind of time scale that’s relevant to humans.”
To calculate mankind’s toll on the world’s wildlife, researchers relied on a metric known as phylogenetic diversity. Cosmos’ Samantha Page explains that this figure takes into account the amount of time an endangered or extinct species took to evolve, whereas the more commonly cited measure of biodiversity simply tracks the number of species present on Earth.
Take shrews and elephants, for example. As Davis tells The Guardian’s Carrington, there are hundreds of varieties of the mole-like critters but just two elephant species. If elephants went extinct, the effect on phylogenetic diversity would be equivalent to chopping off a large branch on the tree of life. Losing a single shrew species, on the other hand, would be like trimming a small twig.
Page offers another way of looking at extinction, comparing the pygmy sloth, which split off from its closest relatives just 8,900 years ago, to the aardvark, which split off 75 million years ago. As the sole remaining species of the Tubulidentata order, the aardvark represents a singular lineage that will be difficult to replace if the animal goes extinct.
According to The Atlantic’s Yong, modern humans wiped out two billion years of mammals’ evolutionary history by the 16th century. Since then, the pace of destruction has rapidly sped up. We lost another 500 million years between 1500 C.E. and the present, and if scientists’ projections prove correct, we’ll lose another 1.8 billion years within the next five decades.
Previous studies have found that early human activity disproportionately affected megafauna, or huge mammals such as giant beavers, armadillos and deer. As Davis tells Yong, these losses are particularly devastating because mega mammals tended to be Earth’s “most evolutionary distinct,” often forming their own branches on the tree of life.
Today, rhinoceroses and elephants are two of the last remaining animal giants, but an Aarhus University press release states that black rhinos are at a high risk of going extinct within the next 50 years, while Asian elephants have less than a 33 percent chance of lasting beyond the 21st century.
All in all, the new findings offers little hope for animal lovers. Prioritizing conservation of phylogenetically diverse creatures, including the black rhino, the red panda and a large lemur species called the indri, could stem the loss of evolutionary history, but as Duke University’s Stuart Pimm, a conservation ecologist who was not involved in the study, tells Carrington, such targeted conservation is difficult in practice.
“It is hard to imagine that a full recovery or either phylogenetic or functional diversity [a measure of the role animals play in their environment] can be achieved within human time-scales,” Shan Huang, an ecologist at the Senckenberg Biodiversity and Climate Research Center who was also not involved in the study, tells Yong. “But by prioritizing conservation for unique and distinctive lineages, we can at least slow down the losses.”
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Meilan Solly||READ MORE
Meilan Solly is Smithsonian magazine's associate digital editor, history.
Around 97 percent. The most important epoch in human history is lost with time. It's the period in time where a bunch of our ancestors ,so accustomed to traveling in small packs realised it's superior to co-operate and help each other, giving rise to civilization.
Answer and Explanation: Modern humans (hom*o sapiens) have existed on Earth for approximately 300,000 years. Human history began to be recorded approximately 5,000 years ago. Using these numbers, we can estimate that only about 1.6% of human history is recorded!
Fossils and DNA suggest people looking like us, anatomically modern hom*o sapiens, evolved around 300,000 years ago. Surprisingly, archaeology – tools, artefacts, cave art – suggest that complex technology and cultures, “behavioural modernity”, evolved more recently: 50,000-65,000 years ago.
Civilization describes a complex way of life that came about as people began to develop networks of urban settlements. The earliest civilizations developed between 4000 and 3000 B.C.E., when the rise of agriculture and trade allowed people to have surplus food and economic stability.
Archaeologists have discovered written records in Egypt from as early as 3200 BCE, which is the accepted date at which history "begins" there. Written records give historians resources to deal with that are more detailed in some ways than other records, such as archaeological or biological remains.
People in power made and make choices to erase knowledge and deprive certain groups from shaping the historical record and sharing their stories with future generations. We can keep searching for this information, but to call it “lost” is to remove the human action that led to its disappearance in the first place.
In relation to the rest of our history, the prehistoric era makes up 99% of our past! Some of the best known monuments in Britain were built during this time, including Stonehenge. Prehistory is split into three main categories, based on developing technologies and the materials they used: Stone, Bronze and Iron.
Humans first evolved in Africa, and much of human evolution occurred on that continent. The fossils of early humans who lived between 6 and 2 million years ago come entirely from Africa.
Kushim (Sumerian: 𒆪𒋆 KU. ŠIM) is supposedly the earliest known recorded name of a person in writing. The name "Kushim" is found on several Uruk period (c. 3400–3000 BC) clay tablets used to record transactions of barley.
Concerning the age of the Earth, the Bible's genealogical records combined with the Genesis 1 account of creation are used to estimate an age for the Earth and universe of about 6000 years, with a bit of uncertainty on the completeness of the genealogical records, allowing for a few thousand years more.
The biblical description of man's approximately 1,700 years of existence before the great Flood is brief, primarily occupying the first seven chapters of the Bible. One of the particularly curious features about the antediluvian world is the immense ages to which the population lived.
In biology, the most recent common ancestors of humans, when traced back using the Y chromosome for the male lineage and mitochondrial DNA for the female lineage, are commonly called the Y-chromosomal Adam and Mitochondrial Eve, respectively. Anatomically modern humans emerged in Africa approximately 300,000 years ago.
From the origin of hairlessness and exposure to UV-radiation to less than 100,000 years ago, archaic humans, including archaic hom*o sapiens, were dark-skinned.
The first encounters began about 8000 generations ago in the Paleolithic era when approximately 75% of deaths were caused by infection, including diarrheal diseases that resulted in dehydration and starvation. Life expectancy was approximately 33 years of age.
No! After the dinosaurs died out, nearly 65 million years passed before people appeared on Earth. However, small mammals (including shrew-sized primates) were alive at the time of the dinosaurs.
The first written records date back a little more than 5,000 years in Egypt and ancient Sumer. The earliest Sumerian records were made using reeds cut at an angle to make wedge-shaped (cuneiform) marks on clay, which was then baked hard.
The span of recorded history is roughly 5,000 years, beginning with the development of Sumerian cuneiform script and continuing until the expansion of Islam in late antiquity. Ancient history covers all continents inhabited by humans in the period 3000 BC – AD 750.
Key takeaways: The world's population is larger than it has ever been, but the total number of people alive today makes up only around 7% (or 1 in 14) of people who have ever lived.
Introduction: My name is Barbera Armstrong, I am a lovely, delightful, cooperative, funny, enchanting, vivacious, tender person who loves writing and wants to share my knowledge and understanding with you.
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