Evolutionary Biology Maps the Human Journey

What is Evolution?

Evolution is the process of change in organisms over time. In biology, evolution refers to the change in the heritable characteristics of biological populations over successive generations. Evolutionary processes give rise to new species, modify existing species, and/or determine the relative abundance of various species. Simply put, evolution is a change in the genetic makeup of organisms over time. To understand evolution, it’s important to know that all organisms have an inheritance. This inheritance comes in the form of genes and is passed down from parent to offspring. Over time, these genes can change, which can lead to new traits in organisms. It’s important to note that evolution is not the same as devolution. In devolution, organisms regress to an earlier, less-evolved state over time. While both processes are forms of change over time, they operate on different principles.

The History of Evolutionary Theory

The concept of the theory of evolution traces its roots back to the 18th century. In 1794, English naturalist and physician Erasmus Darwin published Zoonomia, an analysis of the origins of life that laid the groundwork for the theory of evolution. While Darwin’s work was an important precursor to evolutionary theory, the theory of evolution was not fully formed until the work of British naturalist Charles Darwin. Darwin’s research in the mid-19th century laid the foundations for modern evolutionary theory. In his most famous work, On the Origin of Species using Natural Selection, Darwin outlined the concept of natural selection and its role in the process of evolving species. In the past century, evolutionary biology has expanded to incorporate research in genetics. Today, evolutionary biology is a broad, interdisciplinary field that covers the origins of life, mechanisms of changes in organisms and biodiversity, and the relationships between living organisms.

Key Contributors to Evolutionary Theory

18th-19th Century, Erasmus Darwin and Jean-Baptiste Lamarck. These were the first two scientists to provide a fully-fledged evolutionary theory. While they were incorrect in some ways, they laid the foundation for future evolutionary researchers.

Early 20th Century. Thomas Hunt Morgan, Ronald Fisher, Theodosius Dobzhansky, and J.B.S. Haldane. These scientists contributed to the study of genetics and the development of evolutionary theory. They combined Darwin’s theory with the field of genetics and advanced the field of evolutionary biology.

Later 20th Century - Edward O. Wilson, Stephen J. Gould, and E. O. Wilson. These biologists focused on the biodiversity of different organisms and how the environment affects them. They also studied the relationships between different organisms, leading to a more in-depth understanding of evolutionary theory.

Basics of Evolutionary Biology

Darwin’s Theory of Natural Selection - This is the idea that organisms with traits that suit their environment will thrive, while organisms with weaker traits will die out. This process will cause changes in the genetic makeup of the surviving organisms over time.

Heredity - This is the process by which organisms pass along traits to their offspring. In other words, the genes of parent organisms are passed on to the next generation.

Mutation - This is the process by which genes change over time. Mutations occur naturally over time, and they are often a source of genetic variation.

Stabilizing Selection - This is a type of natural selection in which a change in the environment leads to a change in the genetic makeup of a population. In this case, there is no change in the genetic makeup of the population.

Disruptive Selection - This is a type of natural selection in which a change in the environment leads to a change in the genetic makeup of a population. In this case, there is no change in the genetic makeup of the population.

Importance of Evolution in the Natural World

Evolution is the reason that there are many different species of living things in the world. Evolution is the process by which species change over time. For example, goats have been around since before humans existed. However, they are not the same goats that were around in ancient times. Goats have evolved and changed over time. Through the process of evolution, goats have adapted to the environment in which they live. They have also changed in ways that help them survive. Evolution causes these changes in species. Different species of living things have different adaptations. For example, hummingbirds have long beaks that help them drink nectar from flowers. Kangaroos have strong legs and large pouches that help them survive in the Australian Outback. Evolution explains how these traits developed in different species.

Evolving Through Natural Selection

Natural selection is the process by which organisms with traits that help them survive and reproduce are more likely to pass on their genes to the next generation. Over time, this causes changes in the genetic makeup of the species. For example, let’s say a group of beetles live in a place where there are lots of predators, like birds. Some beetles have traits that protect them from the birds, like camouflage coloring. Out of all the beetles in the group, only the ones that have camouflage coloring will survive and pass on their genes to the next generation. This means that the next generation of beetles will have camouflage coloring, too. This process will continue until there are no more birds in the area. At that point, the camouflage coloring will no longer offer any benefits to the beetles.

Evolving Through Genetic Drift

In this process, changes in the genetic makeup of organisms occur as a result of random events, rather than natural selection. These events are unlikely to happen in a way that changes the genetic makeup of a species. For example, let’s say that a massive flood occurs in an area where a species of bird lives. All the birds in the flood die, except for the ones who live in the highest trees. Over time, the population of birds who were spared by the flood will grow. This means the birds who survived the flood will pass on their genes to the next generation. This is an extreme example of genetic drift, but it illustrates how it works.

Evolving Through Genomic Change

Genomic change occurs when one species evolves into another species. This is a very rare process that can take millions of years to occur. For example, let’s say that a species of fish swims up a river to a place where there’s not a lot of water. The fish might die because there’s not enough water for it to survive. However, some of the fish might survive. They might be smaller because they don’t need as much water to survive. This is an example of a species evolving into another species. The fish are no longer the same fish that they used to be. They have evolved into a new species.

Conclusion

Evolutionary biology is the scientific study of the origins of life, biodiversity, and relationships between organisms. It is also the process by which species adapt over time due to changes in the environment, a process of natural selection, and changes in genes. This process has led to a wide variety of different species that can be studied by scientists. While evolutionary biology studies the origins of species and how they relate to one another, it also details how these species have adapted to their environment. These adaptations are the result of a long process of change over time, known as evolution.