Exam 20: Human Evolution

Which of the following organisms is NOT considered a great ape?

Green and colleagues assessed the degree of past interbreeding between modern Homo sapiens populations and extinct premodern populations by looking at an aspect of genetic diversity known as ________.[three words]

"Robust australopithecines," now classified in the genus Paranthropus,are distinctive as compared to other hominins because of their ________.

The accompanying figure shows that humans have thicker thumb metacarpals than chimpanzees or bonobos,with broader heads.This is directly correlated with humans' ________.

The only hominid skeletal feature that is fairly clearly correlated with the ability to speak is the shape of the ________.

Which genus or genera of hominin is/are most consistently associated with stone tools?

The first close human relative known to have dispersed out of Africa was ________.[two words]

Which piece of evidence BEST supports the "out of Africa" model of the evolution of modern humans?

The accompanying figure shows the percentage of pairwise genetic comparisons within sample populations of living hominids,graphed against the percentage of sequence divergence for each pair.We can conclude from the figure that ________.

Both the "out of Africa" hypothesis and the "multiregional evolution" hypothesis agree that the last common ancestor of all modern humans lived in Africa.Overwhelming fossil and genetic evidence confirms an African origin for modern humans―but that isn't enough,by itself,to decide between the two hypotheses.Explain one of the lines of evidence that does tend to support one or the other of these hypotheses.

The earliest style of stone tools,dating as far back as 2.6 million years,is called ________.

The fossil Sahelanthropus tchadensis from the Djurab Desert of Chad,dated at 6 to 7 million years ago,may be a hominin (i.e.,share more recent common ancestry with humans than with any other ape because of ________.

In 1912,parts of a skull and jawbone were found in a gravel pit near the English town of Piltdown,about 40 miles south of London.These were claimed to belong to a human ancestor with a brain about two-thirds the size of a modern human brain,and a large,protruding jaw."Piltdown Man," or Eoanthropus dawsoni as it was named,was conclusively shown to be a hoax in 1953―pieces of a human skull braincase and an orangutan jaw,stained to look old and to have the same color.(The perpetrator's identity is still not certain.)However,almost from the start,a growing number of scientists were skeptical of Piltdown Man.Discuss two facts about Piltdown Man that would have been increasingly difficult to reconcile with the emerging picture of human evolution in the first half of the twentieth century.

Judging by the nature of modern humans,chimpanzees,and bonobos,which of these traits did the last common ancestor of all three probably NOT show?

Although attempts to date the divergence between humans and chimpanzees using molecular sequence data do not perfectly agree,a rough consensus from multiple analyses would place the divergence date at ________.

Your textbook,and many (but not all)paleoanthropologists,refer to a species more closely related to humans than to chimps as a(n)________.

Vincent Sarich and Allan Wilson estimated that humans diverged from their closest living primate relatives about 5 million years ago.What line of evidence did they use initially?

The accompanying figure shows how levels of a microRNA called miR-320b change with age in the prefrontal cortex of the brains of humans,chimps,and macaques (African monkeys).This may be important for understanding the genetic features that make us human,because microRNAs ________.

________ are fragmentary hominids 30,000 to 50,000 years old,found in a Siberian cave,who astonishingly appear to have interbred with the ancestors of modern Melanesian human populations.

Chimpanzees and gorillas share the trait of knuckle-walking,which humans do not generally have.Why do most scientists NOT classify chimpanzees and gorillas as each other's closest relatives?