Extinction of species: what it is, causes and consequences

The extinction of species is the process by which all members of a species disappear or group of living things. In general, it is a natural process of evolution, by which new species appear and others disappear, which in general are not able to adapt to changes in their way of life or are displaced by new competitors. Thus, natural selection plays a relevant role in this process.

We recommend you read these other articles on the Origin and evolution of animals , the Origin and evolution of plants , What is natural selection and examples and Mass extinctions: what they are, what causes and what they are .

The reasons why species can disappear are diverse, but in general, the most common is the disappearance of the habitat where they live. There have also been many species extinct by humans ; in fact, today, humans are the main responsible for these changes with various activities, for example, with the destruction of natural habitat (for example, climate change is affecting the ice sheets where the polar bear lives), illegal hunting (to which the African rhinoceros is subjected due to its ivory horns) or the introduction of invasive species with which other endemic species cannot compete or alter its ecosystem (such as, for example, the beaver in Argentina and Chile, which are one of the causes of the destruction of forests in Tierra del Fuego).

The doubts are not so much in the causes of the extinction of species, which most people know better, but in the consequences of their disappearance. The most palpable is the loss of biodiversity in a habitat, that is, the lack of members of that species. This, in turn, has consequences since, in an ecosystem, all its members are interrelated to a greater or lesser extent. The disappearance of one of them causes changes, which end up affecting the rest and causing, in turn, that they are more vulnerable to invasive species . This can be seen with the following example:

The kelp forest is a system made up of otters, hedgehogs, and kelp (a type of giant algae). Otters feed on hedgehogs and other crustaceans, which in turn feed on kelp. In turn, the kelp provides shelter for otters and food for other species. In the event that the otters disappear, the urchin populations would increase uncontrollably, in turn causing the disappearance of the kelp and the complete collapse of the entire system. Therefore, in this interrelation, all the participants are necessary for the coexistence of the rest.

The biggest problem with the consequences of the disappearance of a species is the fact that we are not sure how this will affect the system where it lives and there will be an ecological imbalance in the ecosystems that nature will have to readjust, which takes a long time. Herein lies the need for the conservation of biodiversity.

Here are some examples of species that have become extinct throughout evolution:

• The dodo , a flightless bird, extinct during the 18th century, one of the best known examples of extinction of a species caused by man.
• The baiji, a Chinese dolphin endemic to the Yangtze River, declared extinct in 2008.
• The western black rhinoceros, declared extinct in 2011, by poaching.
• The Formosan Clouded Panther, endemic to the island of Taiwan, was declared extinct in 2013, although there was a sighting in 2019.
• Caribbean monk seal, declared extinct in 1952, due to man-made hunting.
• Mexican grizzlie bear, extinct in 1964. Endemic to Mexico, it was one of the largest carnivores in its habitat.
• Javanese tiger, endemic to Indonesia, was abundant until the late 19th century. It is considered extinct as of 1979.
• Giant Pinta tortoise, endemic species of the Galapagos Islands. It became permanently extinct in 2012, when its last specimen, Lonesome George, died at around 100 years old.
• Bucardo, a species of ibex endemic to the Pyrenees, became extinct in 2000.
• The passenger pigeon, the most abundant bird in North America, extinct in 1914.
• Franklin’s tree, native to the United States, became extinct in 1840.
• Flor de Chocolate, although it has been cloned, this Mexican plant cannot be introduced into nature.
• Sandalo by Juan Fernández, from Chile, its extinction dates from 1978.
• Sophora toromiro , a clear example of extinction due to the human species.
• Aeonium mascaense , native to China, this plant suffered a natural extinction.
• Cooksonia, recognized as one of the first plants present on Earth.
• Trapa natans , aquatic plant known as water chestnut.
• The toromiro bush, native to Easter Island, in Chile.
• Araucaria mirabilis , from Argentina.
• Franklinia, although extinct, is kept alive for ornamental purposes.

Here you can discover more Animals extinct by man and 20 extinct plants .

Have you ever wondered how many animals are in danger of extinction? The answer is that today there are more than 5,000 species in danger of extinction and, even more, this data does not stop growing. These are some of the currently endangered species :

• The Amur leopard , endemic to the border between North Korea and Russia, of which between 20 and 35 specimens remain in the wild.
• The Chinese giant salamander, the largest amphibian.
• The blue macaw, which inspired the movie Rio, of which only specimens remain in captivity.
• The Okarito kiwi, endemic to southern New Zealand, of which 250 specimens remain.
• The mountain gorilla, of which there are less than 500 specimens.
• The common sturgeon, which formerly populated all of Europe, and of which today there are only populations in France and the Iberian Peninsula.
• The white oryx, an antelope that inhabited the north of the Sahara, which has recently been reintroduced in Morocco.
• The South China tiger, of which 68 specimens remain in captivity.
• The Californian condor , of which 400 copies remain.
• The leatherback turtle , the largest of the sea turtles.
• Passion flower or passion flower, owes its name to the Passion of Christ.
• Cornflower, its beautiful lily-blue flowers stand out.
• Dionaea muscipula or Venus flytrap, a plant that arouses great curiosity for humans as it is a death trap for flies.
• Populus canescens , the gray poplar, is a rare species typical of the mountain.
• Quecus ilex , the oak.
• Hieracium snowdoniense , endemic to North Wales.
• Sorbus aria , the mostard, with extensive applications and ornamental characteristics.
• Attraylis preauxiana , endemic shrub of the Canary Islands.
• Heliconia brenneri , typically present in mountains that reach 2000 m above sea level.
• Heliconia brenneri , characterized by its lack of chlorophyll.

As it is a natural process, it is difficult to avoid the extinction of species . However, there are many actions that we can take to lessen our impact on this process and to slow down its acceleration. These are some of the measures we can take:

• Prohibit sport hunting of animals.
• Reduce our impact on nature and our ecological footprint and carbon footprint .
• Reduce the exploitation of natural resources.
• Avoid illegal activities in nature and report if any are detected.
• Better invasive species controls.
• Creation of nature reserves .
• Collaboration between entities, administrators, and countries.

In addition, after learning all this about the extinction of species, we recommend you read this other article about Why it is important to protect animals in danger of extinction .

If you want to read more articles similar to Extinction of species: what it is, causes and consequences , we recommend that you enter our Biology category .