Surely you've heard about the evolution of species, haven't you? Although it often seems confusing, the concept of evolution is quite simple, and some theories try to explain how this happens.
→ What is evolution?
Evolution is a process in which living things change over time, often leading to the emergence of new species. These modifications are passed on to descendants, which is why many define evolution as descent with modification as well.
→ How can the study of evolution help to understand Earth's history?
As we study evolution, we realize that the life forms we know today are not the same ones that lived thousands of years ago. This means that species have an evolutionary history and that many changes take place in them until the characteristics we observe today exist.
The species, therefore, are not fixed, have undergone changes throughout their history on the planet and continue to change. Man, for example, did not appear on Earth as we see it today, as there were several ancestral species.
→ What evidence is there that evolution occurs?
Several evidences support the idea of species evolution, among them:
Fossil Evidence: You fossils they are remnants or traces of organisms that lived in the past and are preserved. We know that dinosaurs existed in the past, for example, because ofthe presence of bones, eggs, skin, feces and other materials preserved from these animals. This shows that animals and other organisms that lived in the past are different from today.
homologies: Homologies are common features that indicate a certain relationship between species. The forelimbs of mammals, such as humans, bats and whales, are homologous structures, since, even though they perform different functions, they have the same skeletal elements. This means that, at some point in evolutionary history, these animals had a common ancestor.
Trace structures: Trace structures are those with little or no function for a given organism. They symbolize structures left over from others that were important in the ancestors. As an example, we can mention the presence of bones under the scales of blind fish species that live in caves.
Cellular and molecular evidence: It is possible to observe common cellular and molecular characteristics in different species. Many species, like us and the bonobo monkey, have DNAextremely similar, which indicates kinship.
Heads up: Also read about the natural selection, one of the mechanisms that lead à evolution of species.
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