Question 2: Explain Merit

No other cattle in the world have stayed as pure as the Chillingham wild cattle, which have never bred with an outside herd. They still roam their historic home, a 365-acre park in England walled off in the 13th century for food and hunting, and are thought to descend from the original wild oxen of England. They number only about 40 to 60, and that is the whole world population. The bulls form a dominance hierarchy whose alpha bull is called the “king”. A challenge is usually settled by ritualised fighting, a show of bellowing, pawing at the ground and flinging dirt and debris about, but now and then one escalates to a full-contact fight that ends in injury or death.

Explain how the hierarchy benefits the king and the females, and why fighting is usually ritualised but sometimes escalates to a physical fight.

The 2023 paper, page 5 ↗ Marking schedule, page 3 ↗

Work it out

Try it on paper first. Stuck? Take one hint at a time.

1. 1 The describe answer listed the king’s advantages. How do they raise his chance of success?

   Mating with all the cows means he fathers most of the calves, so his alleles fill the next generation; first access to food keeps him in condition to hold his place.

2. 2 How does the hierarchy raise the females’ chance of success?

   They are protected, and their calves are fathered by the bull that has beaten every rival, so the calves inherit fit alleles and are more likely to survive.

3. 3 How does intraspecific competition make sure only the fittest breed?

   Bulls compete for the king’s place, and only the winner mates. The bull that breeds is the one best at winning, so the calves get the fittest alleles available.

4. 4 Why does that matter to the herd’s gene pool?

   With only the fittest bull breeding, the alleles passed on are the ones that made him fit, so the gene pool stays healthy.

5. 5 Why is fighting usually ritualised?

   Everyone knows their place, so display is usually enough: the weaker bull backs off without injury. An injured bull costs energy to recover, may die, and is a weaker member of a herd that has no outside animals to replace it.

6. 6 Why does it sometimes have to escalate?

   When a resource is scarce, or a younger bull is strong enough to challenge the king, display cannot settle it; a real fight decides which bull is fitter.

What the marker wanted

• Achieved The describe points: hierarchy, ritualised behaviour, the king’s and the females’ advantages, intraspecific competition and when fights turn physical.
• Merit Explains: how the hierarchy raises the king’s chance of success; the females’ chance; how intraspecific competition lets only the fittest reproduce; how ritualised fighting avoids injury, and why injured members are unwanted; that only the fittest breeding keeps the gene pool healthy; and why escalation is sometimes needed. Three make M6.

One answer, N0 to E8. Merit points sit above the Achieved ones: two give M5, three M6.

In our words, from NZQA’s 2023 marking schedule.

Common mistake

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