3.5 billion years ago
There have been many scientists that have worked on the theory of emergence over the years. Emergence theory has been written about by scientists such as Julian Huxley and John Stuart Miller.
They lacked a definitive answer.
You didn't say what scientists, but science today is built on the contributions of scientists from long ago. There are many examples but prominent among them Is Isaac Newton.
False
Accumulating data, especially proof of sea floor spreading.
Scientists theorize that the universe began with the Big Bang around 13.8 billion years ago, when all matter and energy were concentrated into an extremely hot and dense point. This point rapidly expanded, leading to the formation of stars, galaxies, and everything we see today.
Scientists theorize that the first living cells appeared spontaneously. They believe the process took place around four billion years ago.
200 million years
Human habitation of the Americas began approximately 15,000 years ago, with evidence pointing to early human migrations from Asia across the Bering land bridge. This is supported by archaeological findings of early civilizations such as the Clovis culture in North America and the ancient indigenous cultures of Mesoamerica and South America.
There is no specific number of years as it can vary depending on the location and the specific aspect being considered. However, in general, many scientists agree that the Earth was cleaner in the past before industrialization and widespread human activity began to significantly impact the environment.
Which theory states that Homo sapiens began in a single geographical area and spread out from there
Which theory states that Homo sapiens began in a single geographical area and spread out from there
By looking at the fossil records, scientists were able to say approximately when life began. They used radiometric dating of rock layers as one method. See links below for further information:
Scientists estimate that people have been living in the Arctic for at least 30,000 years, with some evidence suggesting a presence as far back as 50,000 years ago. This is based on archaeological findings of ancient human settlements and remnants of tools and artifacts.
Most scientists believe that the first early human beings evolved from a species called Australopithecus around two million years ago. This transition marked the emergence of the Homo genus, which eventually led to the development of modern humans.
Scientists who decided it would be a good idea to make a ratio between how long dogs live and how many human years old they are so that humans could compare their dogs age to what a human would act like at that age.
Scientists estimate that the universe began forming around 13.8 billion years ago during an event known as the Big Bang. This marks the beginning of the expansion of space and the creation of all matter and energy in the universe.