Estimates of the size of these populations are a topic of paleoanthropology. A late human population bottleneck is postulated by some scholars at approximately 70,000 years ago, during the Toba catastrophe, when Homo sapiens population may have dropped to as low as between 1,000 and 10,000 individuals.
The fossil record indicates that Homo sapiens has been around for 315,000 years or so, but for most of that time, the species was rare—so rare, in fact, that it came close to extinction, perhaps more than once.
Historic growth of world population
1000 years BCE the world population was 50 million people. 500 years BCE it was 100 million, and in the year 0 around 200 million people were estimated to live on Earth.
There are three times in history during which humans nearly went extinct. Here's what threatened us, and how we survived.
Assuming a constant growth rate and birth rates of 80 per 1000 through 1 A.D., 60 per 1000 from 2 A.D. to 1750, and the low 30s per 1000 by modern times, 105 billion people have lived on earth, of whom 5.5% are alive today.
By 10,000 B.C., the world's population was around 1 million. 2,000 years later there were about 5 million people on Earth—the same number that live in Finland today.
It is supported by some genetic evidence suggesting that today's humans are descended from a very small population of between 1,000 and 10,000 breeding pairs that existed about 70,000 years ago.
Just as our planet existed for more than 4 billion years before humans appeared, it will last for another 4 billion to 5 billion years, long after it becomes uninhabitable for humans. Shichun Huang is an associate professor of Earth and planetary sciences at the University of Tennessee.
Broadly speaking, evolution simply means the gradual change in the genetics of a population over time. From that standpoint, human beings are constantly evolving and will continue to do so long as we continue to successfully reproduce.
Today, oxygen makes up roughly 21 per cent of our air, but it was virtually non-existent in Earth's early atmosphere. Soon after the advent of photosynthesis 2.4 billion years ago, oxygen levels crept up to 1 or 2 per cent – if you were to breathe this air, you would die almost immediately.
Earth's capacity
Many scientists think Earth has a maximum carrying capacity of 9 billion to 10 billion people.
Vatican City
Also regarded as the “Holy See”, this place holds the smallest population globally. Vatican City is not only the world's smallest entirely independent nation-state but is even one of the least populated countries in the world.
Lower literacy rates are found mostly in South Asia and Sub-Saharan Africa. The world's largest ethnic group is Han Chinese, constituting over 19% of the global population in 2011. In terms of the largest number of native speakers, Mandarin is the world's most spoken language.
Humans in the year 3000 will have a larger skull but, at the same time, a very small brain. "It's possible that we will develop thicker skulls, but if a scientific theory is to be believed, technology can also change the size of our brains," they write.
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.
More reproduction followed, and more mistakes, the process repeating over billions of generations. Finally, Homo sapiens appeared. But we aren't the end of that story. Evolution won't stop with us, and we might even be evolving faster than ever.
There are humans (Bajau Laut- sea nomads) who can hold their breath for longer durations (up to some minutes) underwater. However, it is biologically impossible to evolve (or devolve) to live underwater in a short period.
Part of Hall of Human Origins. Humans are primates–a diverse group that includes some 200 species. Monkeys, lemurs and apes are our cousins, and we all have evolved from a common ancestor over the last 60 million years. Because primates are related, they are genetically similar.
How are humans and monkeys related? Humans and monkeys are both primates. But humans are not descended from monkeys or any other primate living today. We do share a common ape ancestor with chimpanzees.
Climate change is definitely at the top of practically every list of the most important issues facing our planet today. While this issue primarily focuses on global warming, changes in precipitation, air quality, biodiversity, “habitable” zones and many other areas are part of and affected by climate change.
According to a US report, the sea level will increase by 2050. Due to which many cities and islands situated on the shores of the sea will get absorbed in the water. By 2050, 50% of jobs will also be lost because robots will be doing most of the work at that time. Let us tell you that 2050 will be a challenge to death.
Global temperature is projected to warm by about 1.5 degrees Celsius (2.7° degrees Fahrenheit) by 2050 and 2-4 degrees Celsius (3.6-7.2 degrees Fahrenheit) by 2100.
The planet has experienced five previous mass extinction events, the last one occurring 65.5 million years ago which wiped out the dinosaurs from existence. Experts now believe we're in the midst of a sixth mass extinction.
Add all of us up, all 7 billion human beings on earth, and clumped together we weigh roughly 750 billion pounds. That, says Harvard biologist E.O. Wilson, is more than 100 times the biomass of any large animal that's ever walked the Earth.
As of July 2023, Metaculus users estimate a 3% probability of human extinction by 2100. In a 2010 interview with The Australian, Australian scientist Frank Fenner predicted the extinction of the human race within a century, primarily as the result of human overpopulation, environmental degradation and climate change.