Quiz 8 Flashcards
Describe a trait of Homo habilis that it shares with later Homo and that distinguishes it from australopithecines? Describe a trait of Homo rudolfensis that it shares with later Homo and that distinguishes it from australopithecines?
Homo habilis shares reduced teeth and jaw, especially molars, with later Homo species, suggesting that it could be an ancestor for these later species.
Homo rudolfensis possessed a brain larger than that of other apes, which is characteristic of other Homo species but was not found in australpithecines.
Habilis = reduced teeth, rudolfensis = large brain
Of the following which changed in the transition from australopithecines to Homo?
a. Size of molars b. Size of canines c. Stature d. Brain size
a, c, d changed
size of molars decreased, size of canines stayed small, stature favored obligate bipedalism, brain size increased
Describe one anatomical trait and one cultural development that likely contributed to the first migration of hominins out of Africa. When did this migration occur? Name two regions (not just continents) outside of Africa where ergaster/erectus fossils have been found.
Erectus was able to spread out of Africa because the use of stone tools was not limited to a single local ecology. Also, their large brains and reduced molars predisposed them to hunting, so they likely followed moving herds out of Africa. The migration occurred around
Ergaster/erectus fossils have been found in Indonesia and Central Asia.
What form of transportation enabled the earliest hominins get to the island of Java? When did they first arrive? What hominin was first to arrive there?
The earliest hominins to arrive in Java, Homo erectus, were able to make this journey because of low sea levels at various periods over a long 2-million-year period in large plains that would have otherwise been submerged. They likely first arrived approximately 1.7 million years ago.
What species of hominin was first to reach central Asia? When did they arrive? What tool technology did they use?
Homo erectus/ergaster was the first to reach Central Asia approximately 1.7 million years ago. They used Acheulean tool technology, which was sharp and made from carefully selected stone materials, sometimes even volcanic glass.
What form of transportation enabled the earliest hominins get to the island of Australia? When did they first arrive? What hominin was first to arrive there?
Modern humans arrived in Australia approximately 70,000 years ago. They arrived by boat.
Does hominin brain size increase beyond that of apes before or after the discovery of stone tools? With what species of ape or hominin do brains reach their largest average size?
Hominin brain size increased beyond that of apes 3 million years ago, before the rise of Oldowan technology (2.5 million years ago).
Homo sapiens reached the largest average brain size.
Describe a skull feature that is found in all the archaic Homo sapiens (e.g. including the archaic species heidelbergensis, antecessor, and neanderthalensis) and is also shared with anatomically modern Homo sapiens. Describe a skull feature that distinguishes all these archaic species from anatomically modern humans and a skull feature that justifies calling all these species archaic Homo sapiens.
A skull feature found in all Homo sapiens: large brain size, vertical skull
A skull feature found in archaic but not modern Homo sapiens: highly robust skulls
A skull feature that justifies calling archaic Homo sapiens archaic:
What explains our ability to recover DNA from Neanderthals but not from Homo erectus?
Neanderthal bones have not yet been fully fossilized, so mtDNA can still be extracted from them.
Recently the study of head, body, and pubic lice has provided clues to three important events in human pre history:
a) the point at which hominids lost most body hair
b) the point in prehistory when clothing started to be habitually worn.
c) a possible interaction between H. sapiens and H. erectus in the far east
Give the argument used to support one of these claims.
b - Since body lice live and reproduce in clothing and only contact skin to feed, a large recent clade of body lice that began around 72,000 years ago suggests that clothing began to be worn around this time, correlating with human migrations out of Africa at the time.
Even though there are often distinct groups of genes that distinguish populations from the different continents, most of the genetic variation found in the human species can be found within any given population, rather than distinguishing between populations. Explain how this could have evolved?
The presence of the largest amount of genetic variation within a population as opposed to between populations is likely due to the fact that a single group of hominids migrated out of Africa and spread throughout different continents based on the same initial population. All of the present genetic variation evolved within the last 70,000 years and is therefore fairly recent.
