All life forms have one essential purpose:
survival
. This is even more important than reproduction. After all, babies and grannies are alive but don’t reproduce. To be alive is more than passing genes along.
Does life exist under the earth?
This unidentified nematode was found living in the Kopanang gold mine in
South Africa
, nearly one mile below Earth’s surface. The dark, high-pressure depths of Earth’s interior is an unexpected place to find life.
Does life exist?
Evidence suggests that
life on Earth has existed for at least 3.5 billion years
, with the oldest physical traces of life dating back 3.7 billion years; however, some hypotheses, such as Late Heavy Bombardment, suggest that life on Earth may have started even earlier, as early as 4.1–4.4 billion years ago, and the …
How long did life exist on Earth?
The earliest life forms we know of were microscopic organisms (microbes) that left signals of their presence in rocks
about 3.7 billion years old
. The signals consisted of a type of carbon molecule that is produced by living things.
Can life be defined?
Life is defined as
any system capable of performing functions
such as eating, metabolizing, excreting, breathing, moving, growing, reproducing, and responding to external stimuli.
How do we live on Earth?
What makes the Earth habitable? It is the
right distance from the Sun
, it is protected from harmful solar radiation by its magnetic field, it is kept warm by an insulating atmosphere, and it has the right chemical ingredients for life, including water and carbon.
What is life in the world?
There is currently
no consensus
regarding the definition of life. One popular definition is that organisms are open systems that maintain homeostasis, are composed of cells, have a life cycle, undergo metabolism, can grow, adapt to their environment, respond to stimuli, reproduce and evolve.
Who was the first human on earth?
One of the earliest known humans is
Homo habilis
What was the first animal on earth?
Earth’s first animal was
the ocean-drifting comb jelly
What came before dinosaurs?
The age immediately prior to the dinosaurs was called
the Permian
. Although there were amphibious reptiles, early versions of the dinosaurs, the dominant life form was the trilobite, visually somewhere between a wood louse and an armadillo. In their heyday there were 15,000 kinds of trilobite.
Is death absence of life?
Death is not mere absence of life
, and eing dead is not the same as being nonliving. Life and death are like green and red: you can’t be both, but you can be neither. So we know that death is the end of life.
What is needed for life?
Life as we know it requires
biogenic elements
, a source of energy, liquid water, and a suitable, reasonably stable environment for evolution to take place.
Why do we live?
We live
because there are people who love us
, and people we love back. We live because we want to find out things, and learn, and become able to do things that we would like to do. We live because others want us to, and we want them to live along with us. We live because we have hope, and want to see what happens next.
Which planet do we live?
Earth
, our home planet, is a world unlike any other. The third planet from the sun, Earth is the only place in the known universe confirmed to host life. With a radius of 3,959 miles, Earth is the fifth largest planet in our solar system, and it’s the only one known for sure to have liquid water on its surface.
Which planet has most oxygen?
Answer: From the table we see that
Mercury
has the greatest percentage of oxygen in its atmosphere.
What is inside the Earth?
The Earth’s interior is
composed of four layers, three solid and one liquid—not magma but molten metal
, nearly as hot as the surface of the sun. The deepest layer is a solid iron ball, about 1,500 miles (2,400 kilometers) in diameter. Although this inner core is white hot, the pressure is so high the iron cannot melt.
