Section 31.5 (Exam 3) Flashcards
Humans Evolved Among the Primates
What was a major adaptation to arboreal life and distinguished the primates?
Grasping limbs with opposable digits
What are two major clades of primate?
Wet-nosed primates and dry-nosed primates
What groups are wet-nosed primates?
Lemurs and lorises
What groups are dry-nosed primates?
Tarsiers, monkeys, and apes
What are two groups of monkeys?
New World monkeys and Old World monkeys
What features distinguish New World monkeys?
All of them are arboreal and have a long prehensile tail
What features distinguish Old World monkeys?
Some are arboreal, some are terrestrial, and none of them have prehensile tails
What lineage arose from the Old World monkeys?
The lineage leading to modern apes and humans
What are the two groups of apes that came from Old World monkeys?
Asian apes and African apes
What animals are included within Asian apes?
Gibbons and orangutans
What did one lineage of African apes split into about 6 million years ago?
Chimpanzees and the hominin clade
What animals are included within African apes?
Gorillas, chimpanzees, and humans
How are chimpanzees related to humans?
They are our closest relatives
What does the clade hominin include?
modern humans and extinct relatives
What feature did early hominins have?
bipedal locomotion
What advantages did bipedal locomotion afford early hominins?
More energetically economical than quadruped locomotion
Frees forelimbs to manipulate and carry objects
Elevates eyes to look for prey
What genus did the hominin lineage give rise to?
Homo
Which was the first hominin to leave Africa, and spread as far as eastern Asia?
Homo erectus
Describe some characteristics of Homo erectus.
They were as large as modern humans, but with smaller brains and thicker skulls.
Why did Homo erectus have a thicker skull than modern humans?
Because it afforded better protection
What tools did Homo erectus use to survive?
fire and stone tools
What evolutionary trend regarding structures near the skull ocurred in lineages leading to Homo sapiens?
Brain size rapidly increase and jaw muscles decreased in size
What is an example of neoteny in humans?
adult human skull stays about the same shape as the baby skull and is large relative to other features
How does the skull change shape in chimpanzees?
The skull shape changes dramatically with maturation
Why was increasing brain size evolutionarily favored for hominins?
Due to an increasingly complex social life, features that increased communication between individuals would have been favored
What era did several homo species coexist within, and what did they hunt?
The Pleistocene; they hunted large mammals
Which hominin was widespread in Europe and Asia?
Homo neanderthalensis
Name some characteristics of Homo neanderthalensis.
Short and stocky, with large brains
Who were the Denisovans?
A lineage related to Homo neanderthalensis
What did the development of large brains, complex behaviors, and language lead to within Homo sapien culture?
Cultural transmission facilitated domestication of animals and transformation of most societies from hunting and gathering to agriculture and herding
This led to sedentary lives, cities, and occupational specialization
