Question

What do artificial selection and natural selection have in common and how do they differ?

Short answer

Both artificial and natural selection are mechanisms of evolution that lead to changes in species over time, based on favourable traits. Their key commonality is that they both drive evolution and adaptation in species. However, they differ on who or what determines the favourable traits: for artificial selection, it is human decisions while for natural selection, it is environmental factors that ultimately result in an organism's ability to survive and reproduce.

Step-by-step solution

Define Artificial Selection

Artificial Selection is a process in which humans consciously select for or against particular features in organisms. For example, farmers choose to breed cows that produce more milk, or dog breeders may select for particular physical traits in dogs.

Describe Natural Selection

Natural Selection on the other hand is the process in which organisms that are better adapted to their environment tend to survive and produce more offspring. Charles Darwin famously termed this process as 'Survival of the fittest'.

Explain What They Have in Common

Both artificial and natural selection are forms of biological evolution. In both cases, the driving force is the selection of traits that increase an organism’s chances of survival or productivity.

Elucidate How They Differ

The key difference between the two lies in who or what decides which traits are favourable. In artificial selection, humans make this decision often based on their needs or desires. In natural selection, the environment 'decides' based on which traits lead to survival.

Key concepts

Biological Evolution

Biological evolution is the gradual development of species over time. It occurs through changes in the inherited traits of populations from one generation to the next. These changes can result from various factors including mutations, genetic drift, and, importantly, natural and artificial selection. Evolution helps explain the diversity of life on Earth, by accounting for how species adapt to their environments and how complex organisms can arise from simpler ancestors.

Both natural and artificial selection are mechanisms of biological evolution. Although they are driven by different forces, they both result in changes that can lead to the development of new species or the extinction of others. In essence, biological evolution is the backbone of understanding how life forms have progressed and been refined over millions of years.

It's essential to note that biological evolution doesn't work towards a perfect solution. Instead, it works with available genetic diversity to optimize an organism's chance of survival in their specific environment.

Adaptation

Adaptation is a key concept in understanding biological evolution. It refers to the process through which organisms become better suited to their environment. These adaptations can be structural, like the long neck of a giraffe, which allows it to reach tall trees; behavioral, like birds migrating to warmer climates during winter; or physiological, such as the ability to conserve water in desert animals.

Adaptations result from the natural selection process, where advantageous traits become more common within a population over time. The organisms best fitted to their environment tend to survive longer and reproduce more, passing on those advantageous traits to the next generation.

Human influence through artificial selection can also cause adaptations, albeit in a less natural context. Selective breeding in domesticated animals for certain traits, such as faster racehorses or higher-yield crops, showcase adaptation influenced by human preference rather than environment. These adaptations can increase an organism's productivity or appeal, further illustrating the dynamic nature of adaptation in evolution.

Survival of the Fittest

"Survival of the fittest" is a phrase commonly associated with natural selection, although it is not one coined by Darwin himself. It means that individuals best-suited to their environment tend to survive and reproduce more successfully. This concept emphasizes not physical strength alone but fitness, which can include a range of factors such as resilience, reproductive success, and efficient use of resources.

In natural selection, there is a continual "testing" of organisms against their environment. Those with beneficial traits are better at overcoming challenges and therefore are more likely to pass these genes on to their offspring. Over time, this process leads to the distribution of these successful traits within the population.

In artificial selection, "fitness" is defined by human needs. For example, cows bred for higher milk production are considered "fit" not because they naturally thrive better but because they meet agricultural productivity demands. While natural selection fosters "fitness" to natural environments, artificial selection fosters "fitness" to human preferences. Both processes demonstrate how "survival of the fittest" can apply differently depending on the forces at play, natural or human-driven.