Evolution takes place because we successfully adapt to changes in our environments over vast amounts of time, leading to the false belief that evolution occurs only when the environmental change is stable over time so that the adaptive changes can take hold and the species can flourish. After all, if the adaptative pressure goes in one direction and then reverses course, the adaptive changes might never happen or become maladaptive and cause extinction. But the climatic record during human evolution has been extremely variable, especially in the recent past, so it does not support the idea that environmental stability produced our adaptation. This post will discuss the accepted definition of ice ages, glaciations, interglacials, and their effect on human evolution.
Read MoreLanguage is the one thing that truly sets us apart from the rest of the animal kingdom. It has enabled us to adapt to new environments and situations much faster than evolution allows. Indeed, many aspects of language act in parallel with evolution. Since speech leaves no physical clues for archeologists to find, little is known regarding when and how we acquired it. Christine Kenneally explains the problem of exploring the advent of language in her book The First Word. She states, "For all its power to wound and seduce, speech is our most ephemeral creation; it is little more than air. It exits the body as a series of puffs and dissipates quickly into the atmosphere. ... there are no verbs preserved in amber, no ossified nouns, and no prehistorical shrieks forever spread-eagled in the lava that took them by surprise." Scientists have had a difficult time piecing together the story of how we developed language. This post will cover some of their findings.
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