Final answer:
Domestication of plants and animals occurred primarily through option a)artificial selection, where humans selectively bred organisms with desirable traits. This led to morphological changes in domesticated species, which occurred gradually over generations.
Step-by-step explanation:
Domestication and Artificial Selection:
The process of domestication of plants and animals primarily occurred through artificial selection, a mechanism by which humans selectively breed organisms with desirable traits(option a).
This practice has been fundamental for agricultural development, transforming the morphological characteristics of species as well as their genetic makeup. As humans observed and valued certain traits in plants, like larger seeds or less husk, they began to selectively breed plants to enhance these characteristics. Similarly, animals that exhibited favorable traits, such as cows producing more milk, were chosen for breeding over those with less desirable traits.
These changes did not happen overnight. They were gradual, occurring over many generations, leading to significant morphological differences between domesticated species and their wild ancestors. This process was not just limited to directly desirable traits; other attributes such as reduced aggression and increased sociability also became more prevalent in domesticated populations. Interestingly, this interaction with domesticated species also had a feedback effect on human behavior, encouraging traits like cooperativeness and docility as agricultural practices developed. Hence, the concept of human self-domestication arises, suggesting we might have adapted ourselves to better fit into the agricultural lifestyle.
The physical and morphological changes brought about by humans in the domestication process are a testament to the power of selective breeding. Crops like wheat and barley became easier to harvest and more nutritious, while the rise of agriculture itself catalyzed a major shift in human civilization, paving the way for settled life and advancements in various crafts and trade.