Solved: Figure 1: Distribution of continents and diversity of species over time Source:... [IB Environmental systems and societies (ESS)]

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Question

SLPaper 2

Figure 1: Distribution of continents and diversity of species over time

Source: https://phys.org/news/2022-07-environmental-stability-earth-marine-biodiversity.html

With reference to Figure 1, identify when the diversity of species was lowest in the past 400 million years.

[1]

Verified

Solution

around 250 million years ago/Ma/Mya 1 mark

Note: Accept 240–255 Mya.
Do not credit if units (million years/Mya) are not given.

Describe what may have caused the deviation from the general trend at the point 66 milllion years ago in Figure 1.

[2]

Verified

Solution

mass extinction/extinction event / mass extinction of dinosaurs (about 65 Mya) 1 mark

due to meteor/asteroid impact / volcanic activity / climatic change / ice age 1 mark

Identify the relationship between the number of continents and the diversity of species during the past 250 million years.

[1]

Verified

Solution

the greater the number of continents, the greater the diversity / positive correlation (OWTTE) 1 mark

Describe two reasons why there is a relationship between the number of continents and the diversity of species.

[2]

Verified

Solution

Award 1 mark for each correct answer, up to 2 marks:

separation of continents isolates populations leading to (allopatric) speciation;
continents are moved into different climatic regions causing evolution of different species;
continental movement creates new habitats, e.g. mountain ranges/islands;

Outline the role of natural selection in increasing the diversity of species.

[2]

Verified

Solution

Award 1 mark for ecah correct answer, up to 2 marks:

natural selection (resulting from changing environment) acts on existing genetic variation (that has arisen through mutations over the eons);
natural selection increases the survival of fittest genetic variations/traits;
these traits are heritable/passed onto offspring / selected individuals will have higher reproduction potential / so species will adapt to different environments;
the proportion of these traits may increase in some populations/in subsequent generations;
which can lead to speciation/increasing species diversity if there is reproductive isolation;

Solved: Figure 1: Distribution of continents and diversity of species over time Source:... [IB Environmental systems and societies (ESS)] | RevisionDojo

Environmental systems and societies (ESS) International Baccalaureate (IB) Practice Question: Figure 1: Distribution of continents and diversity of species over time Source: https://phys.org/news/2022-07-environmen...