18. What makes us human?
Humans are mammals
Vertebratic animals include
- fish,
- amphibians,
- reptiles,
- birds and
- mammals.
Mammals are animals that give birth to living offspring. These offspring are fed milk from the mother's mammary glands. This separates mammals from other kinds of animals, which do not have mammary glands and do not give birth to living, developed offspring.
Like birds, mammals are warm-blooded animals. This means that they maintain a steady body temperature, even when the air temperature outside is extremely cold or hot.
Many mammals have a protective fur layer and a fat layer. These features help the mammal to maintain their body temperature in cold environments. Humans do not have fur, which is why we need to wear clothes to stay warm.
Mammals have powerful circulatory systems. This makes it possible for mammals to move at great speeds and maintain their body temperature.
Mammals are warm-blooded animals, which means that their body temperature is steady. A gorilla also has a thick fur.
Humans are primates
Humans are primates. Primates are a taxonomic and evolutionary group that also contains species such as the gorilla and the chimpanzee.
Humans can therefore be classified in the following way:
- Humans are vertebrates.
- Humans are mammals.
- Humans are primates.
Primates differ from other mammals in various ways. Most importantly, they have highly developed hands and brains. Humans share these features with other primates, such as gorillas.
Humans consist of cells
Look at your classmates. What are they made of?Like all living organisms, humans consist of cells.
Cells are the building blocks of life. The cell's nucleus contains its genome, or hereditary information. The nucleus is surrounded by cytoplasm, which consists mainly of water.
The cell can contain various organelles. Organelles are structures that fulfill various functions inside the cell. Some organelles can produce energy, whereas others can break down waste material.
The cell is separated from its surroundings by a cell membrane.
Similar cells form tissues
There are different kinds of cells. For example, muscle cells are long, and they have specialized in contracting and relaxing. A nerve cell can sense things and transmit information. Blood cells are small cells that transport materials through the circulatory system. Skin cells are durable and help to protect your body from the outside world.
Usually, similar cells are located next to each other. When similar cells are joined together, they create tissues. For example, your muscles are made of muscle tissue, which in turn consists of muscle cells.
Together, different tissues form organs. Organs are structures that fulfill specific functions in the body. For example, the heart is an organ that consists of muscle tissue, supporting tissue and nerve tissue.
Humans are a unique species
Although humans are similar to other animals, we also differ from other species in various ways.One of the features that make humans unique is our ability to walk upright. This frees up our front limbs, meaning that we can use them to complete various tasks. Other primates, such as chimpanzees, can walk upright only for brief distances.
The human hand is also different from those of other primates. Because human thumbs are located opposite to our other fingers, we are capable of grabbing objects with a precision grip. The precision grip has made it possible for us to build and use all kinds of tools that other animals cannot
Humans are different from other animals in terms of our highly developed brains. The human brain is relatively large and complex. We use our brains to remember, learn and think.
Humans need other people
The cooperation of our brains and mouths make it possible for us to speak and understand what others are saying. Humans can transmit information from one generation to the next by talking. Nowadays, we can also transmit information in all kinds of other ways, such as by writing or making videos.
However, the most important form of communication for us humans is still face-to-face interactions with other people.
How have you communicated with other people during the past week?
Terminology
| Term | Explanation |
|---|---|
| vertebratic animal | An animal that has an internal supporting structure known as a backbone. |
| primate | A kind of mammal with highly developed hands and brains. E.g. chimpanzees, gorillas and humans. |
| cell | Cells are the building blocks of all living organisms. |