How Adaptation Leads to Evolution

Introduction:

The continuous and gradual process of change that occurs over a period of time is referred to as evolution. Scientists have predicted that the Earth is around 4.6 billion years old. Scientists believe that life originated on Earth around 3 billion years ago. It was predicted to be a tiny unicellular prokaryotic cell. Later on, around 2 billion years ago, these tiny prokaryotic cells evolved into larger cells that contained a nucleus. Scientists have predicted that these smaller prokaryotic cells resided in larger cells and got transformed into organelles over the course of evolution. Around one billion years ago, multicellular organisms evolved. It is also anticipated that various animals and plants have been evolving for the past 500 million years.

History of Evolutionary Theory:

It is anticipated that the emergence of thoughts about the process of evolution of species began during the fourth century BC. Several theories of evolution have been proposed by various scientists. Most importantly, Greek philosophers Plato and Aristotle provided their views on the evolution of species on Earth. They believed that each organism on Earth had been created in its present form and remains unchanged. Various evolutionary theories have been proposed by different scientists at different time periods. French biologist, Jean Baptiste Lamarck (1744-1829), has proposed that living things could transfer the acquired traits to their offspring. Later on, this idea was opposed by biologists.

Darwinism:

Darwinism is the most widely accepted theory of biological evolution. It was proposed by Charles Darwin (1809 – 1882), the British naturalist. He coined the phrase “descent with modification.” Darwin’s theory of evolution is based on natural selection. Darwinism states that every species has descended from pre-existing species by reproduction. It also states that species undergo change over time.

Concepts of Darwinism:

The following are the important concepts of Darwinism.

1. Overproduction
2. Struggle for survival
3. Variations
4. Natural selection
5. Speciation

Adaptation and Natural Selection

Natural selection refers to the process that causes populations to change over time. Darwin explained the mechanism of evolution through natural selection. According to Darwin, the evolution of living organisms takes place in such a way that over a period of time, populations adapt themselves to their living environment. Adaptation refers to the difference in characteristics between individuals of a population. Living organisms with variations that are favorable for their survival in a particular environment continue to live. Whereas other organisms which do not have variations do not survive.

Adaptation and Its Significance:

Adaptation refers to variations that make an organism survive better in an environment. In other words, adaptation refers to the changes in behavioral or physical characteristics of an organism that makes it better suited for survival and reproduction in an environment. Only those organisms that are better adapted to their environment are more likely to survive, whereas other organisms without adaptations do not survive.

 Adaptations of Various Organisms to Their Environment:

Living organisms adapt themselves in order to survive better in their living environment. Different organisms exhibit different types of adaptations according to their living environment.

Skunks protect themselves from their predators by emitting bad odors out of their anal glands.

Giraffes adapt themselves with long necks in order to get food from tall trees.

Darwin observed different species of finches on the Galapagos Islands. He observed that finches had adapted different shapes of their beaks according to the type of food they consume.

Types of Adaptations:

The following are the different types of adaptations:

1. Structural
2. Behavioral
3. Physiological

Structural Adaptation:

In order to survive in an environment, some living organisms undergo changes in their structural/physical features. These visible changes are referred to as structural adaptation.

Example: Camouflage

Behavioral Adaptation:

Some organisms undergo changes in their behavior to survive in an environment. These changes are referred to as behavioral adaptation. These changes occur due to changes in their environment or the actions of other organisms.

Example: Migration of birds, mimicry

Physiological Adaptation:

Some organisms undergo changes in their body process for better survival in an environment. These changes are referred to as physiological adaptations.

Example: In a hot environment, camels produce less urine to conserve water.