primates

What order do lemurs, tarsiers, monkeys, and apes belong to?

Primates

What type of digits do primates have?

Digits with flat nails instead of claws

What is a key adaptation of primate fingers?

Skin ridges that form fingerprints

What sensory adaptation do primates have for depth perception?

Forward-looking eyes close together on the face

What is one reason many primate traits evolved?

Adaptations to living in trees

What does a fully opposable thumb enable?

Touching the ventral surface of all four fingers for better dexterity

What are the three main groups of living primates?

Lemurs and lorises/bush babies, tarsiers, and anthropoids

Where are lemurs found?

Madagascar

Tarsiers are more closely related to what group?

Anthropoids

When do the oldest known tarsier fossils date back to?

About 55 million years ago

Where did monkeys first evolve?

Old World (Africa and Asia)

When did New World monkeys first colonize South America?

About 25 million years ago

What caused New and Old World monkeys to diverge?

Separate adaptive radiations over millions of years

When did apes diverge from Old World monkeys?

25–30 million years ago

What genus includes orangutans?

Pongo

Which apes are primarily arboreal?

Gibbons and orangutans

What distinguishes apes from other primates in terms of body?

Long arms, short legs, and no tail

What is a notable trait of apes’ brains?

High brain-to-body-size ratio

When did Homo sapiens arise?

About 200,000 years ago

What are two distinguishing traits of humans?

Upright posture and bipedal locomotion

What is the function of regulatory genes?

They turn other genes on and off

What is the study of human origins called?

Paleoanthropology

What are hominins?

Extinct species more closely related to humans than chimpanzees

What is the oldest known hominin?

Sahelanthropus tchadensis

When did Sahelanthropus tchadensis live?

6.5 million years ago

What feature suggests bipedalism in early hominins?

Foramen magnum positioned under the skull

What is the average brain size of early hominins?

300–400 cm³

Who was Ardipithecus ramidus?

A 1.2 m tall early hominin from 4.4 million years ago

Do humans descend from chimpanzees?

No

What group includes Australopithecus afarensis and A. africanus?

Australopiths

What does the term "gracile" refer to in australopiths?

Lighter feeding structures adapted for soft foods

What are "robust" australopiths characterized by?

Powerful jaws and large teeth

When did hominins begin walking long distances on two legs?

About 1.9 million years ago

When is the oldest evidence of tool use dated?

2.5 million years ago

Who is Homo habilis?

An early Homo species known for tool use ("handy man")

What are two features of Homo ergaster?

Long legs and smaller teeth

What change in Homo ergaster indicated social behavior evolution?

Reduced sexual dimorphism

Who was the first hominin to migrate out of Africa?

Homo erectus

Where did Neanderthals live?

Europe and the Near East

What is one cultural behavior of Neanderthals?

Burying their dead

Did modern humans descend directly from Neanderthals?

No

When did humans and Neanderthals diverge from a common ancestor?

About 600,000 years ago

What does interbreeding evidence between humans and Neanderthals include?

Human fossils containing Neanderthal DNA

What is Homo naledi known for?

Bipedalism and fine motor skills

When did Homo naledi exist?

About 1–2 million years ago

Where was Homo floresiensis discovered?

Indonesia

What are two characteristics of Homo floresiensis?

Short stature and small brain

How old are the oldest Homo sapiens fossils?

195,000 and 160,000 years

When did Homo sapiens first reach the New World?

About 15,000 years ago

What evidence shows symbolic thought in early Homo sapiens?

77,000-year-old artistic carving from South Africa