Exam 6: The Origin and Evolution of Life on Earth

The most common isotope of carbon is

Which approach is currently proving to be the most promising way of determining how life on Earth originated?

The Carboniferous Period began about

The oldest hominid so far discovered dates back to

One theory for the origin of life suggests that life formed spontaneously from increasingly complex chemical reactions on the Earth. This is referred to as

A sample of an ancient sedimentary rock contains slightly less of the isotope carbon-13 than normal. One possible explanation for this is that

Which of the following are possible causes for mass extinctions on Earth?

In 2010, scientists discovered an RNA strand capable of catalyzing biochemical reactions made of

The study of 2-3 billion year old banded iron formations shows that

The earliest Homo sapiens appeared about

Why is the claim of the discovery of microfossils controversial?

What is one reason that early life formed cells?

The first living organisms probably resembled

What is the main potential concern regarding the creation of artificial life?

The probability of Earth being hit by a large asteroid in the next few hundred million years is

How long did it take for oxygen to build up in the Earth's atmosphere to its present levels?

The LEAST significant evolutionary changes in human beings over the past 40,000 years have been

The layered colonies of microbes found in western Australia that resemble some of the Earth's earliest living organisms are called

A large piece of debris that only partially burns up in the atmosphere, leaving a fragment to hit the surface, is called a

Impacts of large asteroids on the Earth's surface generally result in