During the period when living things appeared on Earth, the surface level of ultraviolet (UV) radiation is believed to have been much higher than current levels, because oxygen levels were too low to form an ozone layer. This UV radiation would have damaged living cells that were not protected, suggesting that the earliest life was in warm water around deep-sea volcanic vents.
However, some scientists have theorized that a hydrocarbon haze in the atmosphere could have compensated for the lack of upper level absoption, while providing the surface heat necessary for living organisms.
A. Protista:Objective evidence of their existence dates back to 1.5 billion years ago in the fossil record. Bacteria, the first group of organisms to have evolved on Earth, are not included in the list of options.
The first eukaryotic organisms on earth were likely single-celled organisms such as protists, which are a diverse group of organisms that have a nucleus and other membrane-bound organelles. These organisms are thought to have evolved around 1.6-2.1 billion years ago.
The scientific explanation for how life began on Earth is through a process called abiogenesis, where simple organic molecules combined and evolved into more complex structures over time, eventually leading to the first living organisms.
i think that the first planet existed 4.7billion years ago. Because the Sun's age is thought to be 5billion years ago and the earth 4.5billion, scientists know that Earth was not the first planet.
During the Ordovician period, the first land plants evolved, as well as the first jawless fish, jawed fish, and arthropods like trilobites. This period also saw the emergence of the first coral reefs.
To Much UV Radiation! :)
They didn't come to earth they evolved here
eff the time in wich life first evolved on earth!!
The first human on Earth is believed to be Homo sapiens, who evolved around 300,000 years ago in Africa. There is no single identifiable first person to have arrived on Earth as humans evolved over time.
Impossible to say. Comets have been striking the earth since before life evolved on the earth
Cat didn't "come to Earth". They evolved here about 25 million years ago.
It is not possible to determine the first person to walk on Earth as walking evolved over time as a means of mobility for early humans. Archaeological evidence suggests that bipedalism (walking on two legs) emerged in hominids approximately 4-6 million years ago.
No, the first vertebrates evolved long before the Mesozoic. The first vertebrates, small jawless fish, evolved around 520 million years ago. Land animals had even evolved long before the Mesozoic Era.
Oxygen evolved for first time. Many compounds were oxidised
It is believed that the first humans evolved from apelike ancestors in Africa around 200,000 years ago. There is no specific "first person" who landed on Earth since humans have existed on this planet for thousands of years.
I believe Echinoderms evolved first.
Scientists think that the first life forms appeared on Earth about 3.6 billion years ago. These were simple cells that eventually evolved into the abundance of life we see today.