1. 1
   For most of the twentieth century all giraffes were classified as one species, Giraffa camelopardalis, with several subspecies. In 2016 a study comparing DNA from giraffes across Africa found large genetic differences between some populations and proposed that there are four separate species. Other biologists continue to treat giraffes as a single species. One of the proposed species, the northern giraffe, would have fewer than 6000 individuals in the wild.

   (a)

   Comparing DNA from giraffe populations across Africa measures which level of biodiversity?

   [1 mark]

   • AEcosystem diversity
   • BSpecies evenness
   • CGenetic diversity
   • DHabitat diversity

   (b)

   Which statement best describes the disagreement about giraffe classification?

   [1 mark]

   • A"Splitters" recognise four species and "lumpers" one, because the same observations can be classified in different ways
   • BIt shows that DNA evidence is unreliable
   • C"Lumpers" recognise four species and "splitters" one, because lumpers rely on DNA evidence
   • DIt proves that giraffes are evolving into four species at the present time

   (c)

   Suggest how classifying giraffes as four species rather than one could affect their conservation.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   The North Island giant moa (Dinornis novaezealandiae) was a large, flightless bird up to about 2 m tall that lived in New Zealand, where there were no land mammals other than bats before humans arrived. Moas laid few eggs and took several years to reach maturity. Polynesian settlers reached New Zealand around 1300 CE, and moas were extinct within about 150–200 years. The Caribbean monk seal (Neomonachus tropicalis) was hunted from the 1700s for the oil in its blubber; it was last reliably seen in 1952 and was declared extinct in 2008.

   (a)

   Which cause of extinction is common to both case studies?

   [1 mark]

   • ASpread of invasive alien species
   • BNatural climate change
   • CUrbanization
   • DOver-exploitation by human hunting

   (b)

   Which feature of moas made them especially vulnerable to human hunting?

   [1 mark]

   • AThey could fly long distances to escape
   • BThey had evolved without mammalian predators and were large, flightless and slow to reproduce
   • CThey lived in the sea, where they were easily caught
   • DThey bred quickly, so the population grew too large for the habitat

   (c)

   Explain why these extinctions are regarded as part of a sixth mass extinction rather than as normal background extinction.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   Volunteers in a citizen-science scheme walked the same 2 km route through a grassland nature reserve once a week from April to September, recording every butterfly seen. In 2005, 12 volunteers took part; they recorded 22 species, and no single species made up more than 15% of the individuals counted. In 2025, 85 volunteers took part; they recorded 17 species, and two species, the meadow brown and the ringlet, together made up 70% of all individuals counted. Volunteers identify butterflies using a field guide, and the data are sent to a national recording scheme.

   (a)

   Using the data, describe the changes in species richness and evenness between 2005 and 2025 and state what they indicate about biodiversity in the reserve.

   [3 marks]

   (b)

   Evaluate the use of these citizen-science data as evidence of a biodiversity crisis.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   Mixed dipterocarp forest is the tall lowland rainforest of Southeast Asia, including Borneo and Sumatra, dominated by trees of the family Dipterocarpaceae. It is among the most species-rich ecosystems on Earth. Since the 1970s large areas have been selectively logged and then cleared, much of the land being converted to oil palm plantations. Dipterocarp seeds cannot survive drying or freezing, and most dipterocarp species produce seed only every few years, in mass fruiting events. Animals of these forests include the critically endangered Bornean orangutan.

   (a)

   Explain how human activities have caused the loss of mixed dipterocarp forest and how this loss reduces biodiversity at the ecosystem, species and genetic levels.

   [6 marks]

   (b)

   Discuss which approaches to conservation would be needed to protect the biodiversity of mixed dipterocarp forest.

   [6 marks]

   Total for question 4: 12 marks

End of questions