Species

A species is a group of living organisms that are similar to each other and can have babies, or offspring, together. These offspring can also grow up and have their own babies. For example, all domestic dogs belong to the same species because they can breed with one another, even if they look very different. On the other hand, dogs and cats are not the same species because they cannot have offspring together.

Scientists use the idea of species to organize and understand the great variety of life on earth. There are millions of known species, from tiny bacteria to giant whales. Every species has its own scientific name, often written in Latin, such as Homo sapiens for humans or Panthera leo for lions. These names help scientists all over the world identify exactly which living thing they are talking about.

Members of a species usually share similar body structures, behaviors, and genetic information. However, individuals can still be different from each other. For example, there are many colors and sizes of flowers in the same species, or many shapes of dogs within the same species. These differences come from small changes in genes, which help species adapt to their environments over time.

Over long periods, one species can change into another through a process called evolution. When groups of the same species become separated—such as by mountains or oceans—they may slowly become so different that they can no longer reproduce with each other. At that point, they become new species. This is how life on Earth has grown and diversified over millions of years.

Scientists estimate there may be over 8 million species on Earth, but many have not yet been discovered. Some live deep in the ocean or hidden in rainforests. Sadly, some species are in danger of disappearing forever due to loss of habitat, pollution, or climate change. When a species dies out completely, it is said to be extinct. Protecting endangered species helps keep Earth’s ecosystems balanced and healthy for all life forms.