Category Science

Why do moles build hills?

Moles spend a large part of their lives in a self-dug burrow system below the ground. The animals push the loose earth that is a result of digging to the earth’s surface after every 50-100 cm. The result is a typical molehill, about 20 cm high. Sometimes we also come across huge hills with air holes all around. Below these molehills the moles make a nest in which they give birth to their young ones. 

Which animals live in our gardens?

A lot of activities are carried out in our gardens by animals and insects living underground, such as moles, rats, and earthworms. Upon a closer look, we can also find animal tracks on the leaves of the spherical oak-apple tree or the fine webs with which spiders catch their prey. Besides the animals hidden underground, there are birds that chirp and fly around in the gardens. 

 

 

 

 

What does ‘survival of the fittest’ mean?

‘Survival of the fittest’ describes the evolution theory of Charles Darwin. In the struggle to survive, the species that are healthy, strong, and have adapted themselves best to their environment will win. They ensure their survival through healthier genetic material that is passed on to their offspring. Thus, a giraffe with a longer neck can reach leaves high on the trees to feed himself. While a giraffe with a shorter neck may stay hungry, since he has access only to the leaves lower on the tree. Eventually, the hungry giraffe may become so weak that he falls prey to lions. 

Who was Charles Darwin?

Charles Darwin (1809-1882) was a British naturalist. At a time, when people still believed that each living creature was created by God, he began his research on finches on the Galapagos Islands to the west of South America. He found that all finches originated from a single species. This turned the prevalent picture of nature as God’s creation upside down and he faced a lot of opposition from the Church. However, his theory was accepted quickly by his colleagues, and when he published his ‘theory of evolution’, the book was quickly sold out. 

 

Why did dinosaurs become extinct?

Dinosaurs existed on Earth 65 million years ago. Today, the scientists believe that their mass extinction was triggered by a huge meteorite hit to the east of Mexico. The meteorite impact caused blasts and flood waves. Huge quantities of poisonous gases filled the Earth’s atmosphere. Then there was acid rain that polluted the seas and the plants died. Huge dust clouds blocked the heat from the sun and it became cold. The cold-blooded dinosaurs became sluggish and starved. Young ones did not hatch from their eggs. Only the small animals, which adapted themselves quickly and did not need a lot of food, survived.