smc-4312-07-Rock structure/formation

Ancient cave drawings contribute evidence of cognitive changes that are unique to modern humans, Homo sapiens. Biologists argue that these unique cognitive changes in H. sapiens allowed cultural evolution that would have been impossible in other hominin species.

Describe how ancient cave drawings contribute evidence of cultural evolution in H. sapiens. (2 marks)

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Cave drawings depicting animals have been found on stalagmites in the Ardales Cave in south-west Europe. A stalagmite is a rock formation that grows upwards from a cave floor, as shown in the image below. Over a long period of time, water, containing minerals, dripped from the cave roof, solidified and formed a transparent layer on top of the drawings on the stalagmites.

A team of scientists dated the mineral deposits in the solid, transparent layer using uranium-thorium dating. They found that some of the mineral deposits are 65 000 years old.

What conclusion can be made about the age of the ancient drawings on the stalagmites? Justify your response. (2 marks)

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The table below shows the arrival dates of some hominin species to the European continent as well as their extinction dates. The dates are the best estimates based on fossil evidence from multiple sites and genetic data.

\( \textbf{Hominin species} \)	\( \textbf{First appearance in Europe} \) \( \textbf{(years before present)} \)	\( \textbf{Time of extinction} \) \( \textbf{(years before present)} \)
\( \text{Homo sapiens} \)	\(45\ 000\)	\( \text{not extinct}\)
\( \text{Homo neanderthalensis} \)	\(130\ 000\)	\(30\ 000\)
\( \text{Homo heidelbergensis} \)	\(800\ 000-600\ 000\)	\(400\ 000-200\ 000\)
\( \text{Homo erectus} \)	\(1\ 200\ 000-600\ 000\)	\(143\ 000\)

How does the discovery of the drawings in the Ardales Cave challenge the view that the art of cave drawing first arose in H. sapiens? In your response, refer to the evidence provided in the table and above. (2 marks)

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a. Answers could include two of the following:

→ Cave drawings show information being passed through generations.

→ The paintings often depict changing hunting techniques or dreaming stories over time.

→ Increasing complexity of these cave drawings over time shows the development of complex thought and symbolic relationships in H. sapien tribes.

b. → The drawings must be a minimum of 65,000 years old.

→ This is because they must be at least as old as the mineral layer on top of them.

c. → H. sapiens are believed to have arrived in Europe 45,000 years ago.

→ The dating shows the drawings are a minimum of 65,000 years old.

→ Therefore the data suggests that either H. neanderthalensis drew the art, or H. sapiens arrived earlier than currently believed.

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a. Answers could include two of the following:

→ Cave drawings show information being passed through generations.

→ The paintings often depict changing hunting techniques or dreaming stories over time.

→ Increasing complexity of these cave drawings over time shows the development of complex thought and symbolic relationships in H. sapien tribes.

b. → The drawings must be a minimum of 65,000 years old.

→ This is because they must be at least as old as the mineral layer on top of them.

♦ Mean mark (b) 49%.

c. → H. sapiens are believed to have arrived in Europe 45,000 years ago.

→ The dating shows the drawings are a minimum of 65,000 years old.

→ Therefore the data suggests that either H. neanderthalensis drew the art, or H. sapiens arrived earlier than currently believed.

Distinguish between relative dating and absolute dating of fossils. (2 marks)

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Students found three fossils (A, B and C) at an archaeological site.

The students concluded that their data were conflicting and they could not determine the relative ages of the fossils.

Evaluate the students' conclusion with reference to the data presented. (4 marks)

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i. Relative vs absolute dating:

→ Relative dating is used to compare fossils, giving scientists data to determine if one fossil is older/younger than another.

→ Absolute dating can provide a quantitative value for the actual age of individual fossils.

ii. Evaluation of conclusion:

→ Fossil B is located at a lower depth than fossil A, however, the strata that contains fossil A is below the strata that contains fossil B.

→ This has occurred because the landscape was folded via geological processes, pushing up some of the strata containing fossil A and pushing down the strata containing fossil B. Therefore, fossil A is the older of the two.

→ Fossil C is younger because it is located in a higher strata than the other two fossils.

→ In Figure 2, fossil A is shown to have an age of four half-lives of \(\ce{C^{14}}\), fossil B three half-lives and fossil C one half-life. This evidence suggests fossil A is the oldest and fossil C is much younger.

→ Therefore the students’ conclusion is incorrect as the graphical data is consistent with the mapped data.