Biodiversity Change Caused by Genetic Techniques
Genetic techniques can alter biodiversity in more than one direction. They may support conservation and species management, but they may also reduce variation through uniformity or create ecological trade-offs. This lesson evaluates biodiversity effects at genetic, species and ecosystem levels rather than treating biotechnology as automatically beneficial or harmful.
Download this lesson's worksheet
Use the PDF for classwork, homework or revision. It includes key ideas, activities, questions, an extend task and success-criteria proof.
Think First
A student says, “If biotechnology helps a crop survive better, then it must increase biodiversity.” Another says, “Biotechnology always reduces biodiversity because it interferes with nature.”
Write why both statements are too absolute. Then explain why biodiversity effects should be judged across more than one level.
Know
- Biotechnology can increase, decrease or have mixed effects on biodiversity.
- Biodiversity should be evaluated at genetic, species and ecosystem levels.
- Uniformity and conservation support can both be outcomes of genetic techniques.
Understand
- Improved productivity is not the same thing as improved biodiversity.
- Reduced genetic variation can increase vulnerability even if short-term output improves.
- Some technologies may support threatened populations or conservation planning.
Apply
- Evaluate biotechnology effects with balanced language.
- Compare monoculture risk with conservation-genetics benefit.
- Write biodiversity-focused rather than production-only responses.
Biodiversity effects should be analysed at genetic, species and ecosystem scales
A biotechnology can improve one level of biodiversity while harming another, so a single yes-or-no judgement is often too simple.
How genetic techniques affect biodiversity
Genetic level
Ask whether variation within populations is being increased, maintained or reduced.
Species level
Ask whether species persistence, abundance or range is being supported or undermined.
Ecosystem level
Ask whether communities, habitats and interactions are becoming more stable, less stable or altered in uncertain ways.
This framework prevents superficial answers. The same genetic technique may raise productivity in one crop system but reduce genetic diversity in that crop, while also changing ecological relationships in the surrounding environment.
Genetic techniques can reduce biodiversity when they promote uniformity or narrow selection
Genetic uniformity
- Widespread use of a few successful varieties can reduce genetic diversity.
- Lower variation may increase vulnerability to disease or environmental change.
Monoculture systems
- High productivity may come with lower crop diversity.
- Associated ecosystems may also become less varied or more vulnerable.
Ecological uncertainty
- Some changes may affect non-target species or ecological interactions.
- Impacts can be difficult to predict perfectly in complex ecosystems.
Genetic techniques can also support biodiversity through conservation and management
Biotechnology does not only threaten biodiversity. Conservation genetics, population monitoring, breeding management and disease screening can help preserve threatened populations, identify low-diversity populations, or guide strategies that reduce inbreeding and improve long-term survival.
Conservation support
- Genetic analysis can identify populations at risk.
- Management can target inbreeding problems or low diversity.
Disease management
- Genetic tools can help protect vulnerable species or breeding programs.
- May support survival of threatened populations.
More informed planning
- Data from biotechnology can improve conservation decisions.
- Better decisions may support biodiversity across multiple levels.
Many biodiversity outcomes are mixed rather than purely positive or negative
A strong HSC evaluation avoids slogans. A technology may increase food production and reduce one pressure on land use, but still narrow crop genetic diversity. A conservation technology may help one species, but require continued human management or create trade-offs elsewhere. The correct conclusion is often conditional.
Balanced language
- “May increase” or “may reduce” biodiversity depending on the context.
- “Positive at one level, negative at another” is often the strongest answer.
- Avoid “always” and “never” claims.
That kind of judgement prepares students for the final biotechnology synthesis in the next lesson.
Core biological claim
Genetic techniques can have positive, negative or mixed effects on biodiversity.
Mechanism or process
They may reduce diversity through uniformity and monoculture, or support biodiversity through conservation genetics and informed management.
Common exam error
Equating improved productivity with increased biodiversity.
Evaluative sentence starter
Although the genetic technique may improve productivity or conservation in one context, its biodiversity effect depends on whether genetic, species and ecosystem diversity are maintained or reduced.
Look back at what you wrote in the Think First section. What has changed? What did you get right? What surprised you?
Activities
Activity 1 - Level check
For each statement, identify whether the biodiversity effect is mainly at the genetic, species or ecosystem level.
1. A crop system relies on one dominant genotype.
2. A conservation program prevents extinction of a threatened species.
3. A change in agricultural practice affects surrounding ecological interactions.
Activity 2 - Mixed judgement
Write one short paragraph explaining how a biotechnology could improve one aspect of biodiversity while reducing another.
Multiple Choice
1. Biodiversity should be considered at which levels?
2. Why can widespread use of one crop genotype reduce biodiversity?
3. Which example best shows a positive biodiversity role of biotechnology?
4. Which statement best evaluates biotechnology and biodiversity?
5. Which statement is the best evaluation of monoculture in relation to biodiversity?
Short Answer
6. Explain how biotechnology can reduce biodiversity in some agricultural systems. 3 marks
7. Compare a negative biodiversity effect and a positive biodiversity effect of genetic techniques. 4 marks
8. Evaluate the claim: “If a biotechnology helps one species survive, then it must improve biodiversity overall.” 5 marks
Rapid Review
Genetic, species and ecosystem.
Uniformity can reduce genetic diversity and resilience.
Conservation genetics can help manage threatened populations.
Confusing productivity gain with biodiversity gain.
Revisit Your Thinking
Return to the two absolute claims about biodiversity. You should now be able to reject both and explain that biotechnology effects can be positive, negative or mixed depending on context and the biodiversity level being assessed.
Answers and Explanations
▼Activity 1 - Level check
1. Mainly genetic level.
2. Mainly species level.
3. Mainly ecosystem level.
Activity 2 - Mixed judgement
A strong answer would explain that a biotechnology might improve species survival or crop productivity in one context, while simultaneously reducing genetic diversity or altering ecosystem interactions in another. The key is to make the trade-off explicit.
Multiple Choice
1. D - Biodiversity should be analysed at genetic, species and ecosystem levels.
2. B - One dominant genotype can reduce genetic diversity and resilience.
3. A - Conservation genetics can support threatened populations positively.
4. C - This is the best balanced evaluation.
5. B - Monoculture may help productivity while reducing diversity and resilience.
Short Answer Model Responses
Q6 (3 marks): Biotechnology can reduce biodiversity when it promotes widespread use of a few genetically similar varieties [1]. This lowers genetic diversity within crop populations [1]. Reduced diversity can increase vulnerability to disease or environmental change [1].
Q7 (4 marks): A negative biodiversity effect is reduced genetic diversity through monoculture or heavy reliance on a few successful genotypes [1]. A positive biodiversity effect is the use of conservation genetics to help manage threatened populations [1]. The comparison is that one reduces variation, while the other may help preserve or manage it [1]. Therefore genetic techniques can push biodiversity in different directions depending on how they are used [1].
Q8 (5 marks): The claim is too simple because helping one species survive does not automatically improve biodiversity overall [1]. It may be positive at species level if a threatened population is supported [1]. However, the same intervention may have mixed or uncertain effects at genetic or ecosystem level [1]. For example, it might reduce genetic diversity or alter ecological interactions [1]. Therefore biodiversity should be judged across multiple levels rather than assumed to improve overall from one apparent success [1].
Mark lesson as complete
Tick this once you have finished the lesson, questions and review.