Biology • Year 11 • Module 3 • Lesson 8

Human Evolution

Lock in the core vocabulary, the key morphological trends, the major hominid species, and the evidence types used to reconstruct human evolutionary history.

Build · Vocab & Recall

1. Term–definition match

The eight definitions below are shuffled. In the right-hand column write the matching term from this list: hominin, bipedalism, cranial capacity, prognathism, Australopithecus, foramen magnum, mosaic traits, ancient DNA. 8 marks

#Definition (shuffled)Matching term
1.1Walking upright on two legs.
1.2The volume of the interior of the cranium, used as a proxy for brain size.
1.3A member of the tribe Hominini, including modern humans and their ancestors.
1.4A protruding jaw characteristic of early hominins and great apes.
1.5An early hominin genus that lived approximately 4–2 million years ago; includes the famous specimen known as Lucy.
1.6The opening at the base of the skull through which the spinal cord passes; its position indicates posture.
1.7A combination of both primitive and more derived features in the same organism, seen in Homo naledi.
1.8Preserved genetic material extracted from fossil specimens that can test relatedness and reveal interbreeding between lineages.
Stuck? Revisit the Key Terms panel and Cards 1–3 of the lesson.

2. Hominid species recall

Complete the table by filling in the missing information. Use the lesson’s species summary table as your source. 8 marks (1 each)

SpeciesApproximate dateKey significance
Australopithecus afarensis
Homo habilis~2.4–1.4 MYA
~1.9 MYA–117,000 years agoUsed fire, made Acheulean tools, first Homo to leave Africa.
Homo naledi
Homo sapiens~300,000 years ago to present
Stuck? Revisit Card 2 of the lesson.

3. True or false — with correction

For each statement, circle T or F. If the statement is false, write the corrected version on the line below. 8 marks (1 for T/F, 1 for correction where needed)

3.1 Humans evolved directly from modern chimpanzees.    T  /  F

3.2 A more centrally positioned foramen magnum is evidence that a hominid walked upright on two legs.    T  /  F

3.3 Lucy (Australopithecus afarensis) had a larger brain than modern humans.    T  /  F

3.4 Homo naledi has a mosaic of primitive and more modern features, challenging simple linear models of human evolution.    T  /  F

Stuck? Revisit the Misconceptions box and Cards 1–2 of the lesson.

4. Function recall

Answer each question in 1–2 sentences using precise terms from the lesson. 8 marks (2 each)

4.1 State two anatomical features used as evidence for bipedalism in hominid fossils.

4.2 Why is Australopithecus afarensis important evidence against the idea that large brains evolved first?

4.3 What can ancient DNA reveal about human evolution that fossil bones cannot?

4.4 Why is human evolution described as branching rather than a single straight line?

Stuck? Revisit lesson Cards 1, 2 and 3.

5. Cloze — complete the paragraph

Fill each blank with the correct word from the word bank below. Use each word once only. 8 marks

Word bank:   ancestor  |  bipedalism  |  branching  |  chimpanzees  |  fossils  |  interbreeding  |  mosaic  |  prognathism

Humans are one of the great apes, and we share a common          with            rather than descending from them. Several morphological trends appear in the hominid record:            (upright walking on two legs) appears early, followed by a general increase in brain size and a reduction of            (jaw projection). Homo naledi is particularly important because it shows a          of primitive and more modern traits, demonstrating that the record is            rather than linear. Human evolution is reconstructed from         , tools and ancient DNA. Ancient DNA confirmed            between modern humans and Neanderthals.

Stuck? Revisit the lesson Key Terms panel and Cards 1–3.
Answers — Do not peek before attempting

Q1 — Term–definition matches

1.1 bipedalism • 1.2 cranial capacity • 1.3 hominin • 1.4 prognathism • 1.5 Australopithecus • 1.6 foramen magnum • 1.7 mosaic traits • 1.8 ancient DNA.

Q2 — Hominid species table

A. afarensis: ~3.2 MYA | Lucy; clearly bipedal but small-brained, showing upright walking came before large brains.

H. habilis: “Handy Man”; associated with regular stone-tool use and a larger brain than Australopithecus.

Species: Homo erectus.

H. naledi: ~335,000–236,000 years ago | Announced 2015; mosaic of primitive and modern features, challenging simple linear stories.

H. sapiens: Modern humans; African origin, Out of Africa dispersal, interbreeding with Neanderthals and Denisovans confirmed by ancient DNA.

Q3 — True / False with correction

3.1 False. Correction: Humans and chimpanzees share a common ancestor; neither evolved from the other. The two lineages diverged approximately 6–7 million years ago.

3.2 True.

3.3 False. Correction: Lucy had a much smaller brain than modern humans (approximately 450 cc). She was bipedal with a relatively small brain, which is why she is important evidence that bipedalism appeared before large brains.

3.4 True.

Q4.1 — Anatomical evidence for bipedalism

Any two of: a more centrally positioned foramen magnum (skull balanced over upright spine); a broader pelvis; an inward-angled femur; development of a foot arch.

Q4.2 — Why A. afarensis matters

Lucy was clearly bipedal (shown by pelvis, femur angle and foramen magnum) but had a cranial capacity of only about 450 cc — far smaller than modern humans. This directly contradicts the idea that large brains were the first feature to evolve; bipedalism appeared before brain enlargement.

Q4.3 — What ancient DNA reveals

Ancient DNA can test relatedness directly and reveal interbreeding between lineages. For example, it showed that modern non-African populations carry Neanderthal and Denisovan ancestry — something impossible to detect from fossil morphology alone.

Q4.4 — Why human evolution is branching

Multiple hominid species coexisted at various points and showed different combinations of features. Homo naledi’s mosaic traits, and evidence that several Homo species overlapped in time, show that evolution was not a neat ladder from primitive to modern but a branching pattern of related lineages.

Q5 — Cloze answers (in order of blanks)

ancestorchimpanzeesbipedalismprognathismmosaicbranchingfossilsinterbreeding