How do the life of our ancestors differ from the way of life of the 21st century

Well, depends which period we are discussing about, but in general our ancestors didn't have technological improvements as we do today that could enable them to live easier. Also, people lived in different types of buildings, ate different food, their immune system wasn't developed, were dying at young age...

Explanation:

Technological improvements throughout history led us to what we are today.

In prehistory our ancestors lived in caves, in the open, had to fight every day to survive, to have enough resources.

In the Middle Ages average life expectancy was around 25 to 35 years. Today it goes even above 80.

We have mobile phones, computers, airplanes, our ancestors sometimes had to wait to obtain certain information even for months.

b. africa to the americas

explanation:

consider an orange peel: if you want to try and lay it flat, you have to stretch it, we know exactly how things are being stretched or squashed at any given point. we have many different map projections because each has different patterns of some projections can even preserve certain features of the earth without