L3 Tosh - Observing and Mapping Biodiversity

Question 1

What are the 3 methods by which you can map biodiversity

Answer 1

1. Geology - conditions when deposits laid down and dates
2. Biological materials - indirectly, fossils e.g. crocodiles in the arctic, palms in Alaska
3. Stable isotopes - they dont decay differ physically
   - water containing lighter isotopes evaporates more quickly - so at higher temperatures

Question 2

What kinds of conditions preserve biological material well?

Answer 2

Peat - good preservative - tollund man

Siberia as you get a combination of swampy condition and permafrost - can find volley mammoths

Question 3

Apart from animal fossils what else can be looked at?

Answer 3

Pollen fossils can be found in places such as the Sale valley in france. Different depths of pollen laid down

Question 4

How can Vostock Ice Cores be used to assess the environment?

Answer 4

Little bubbles of CO2 get stuck in the ice which can be analysed, so at different ice depths you can see what the temperature is, due to O2 : CO2 ratios at the time

Question 5

Give examples of changing species affinities indicating climate change at each

a) tertiary (65mya)
b) Eocene (40mya)
c) Miocene (20mya)

Answer 5

a) tertiary - Sheppey clay found near the Thames river - has lots of fossils in - palm leaves, showing the climate was much warmer. Then pine then oak found showing the progression of climate
b) Eocene - species affinities changed - 2/3rds of deposits with present relatives in warm temperate forests - pine
c) Miocene - increasingly modern flora - sycamore, beech ,oak

Question 6

How did glaciation create land bridges?

Answer 6

Glaciation lowered sea levels, causing the appearance of bridges between land masses
e.g. The UK and Europe

This aided migration but also massive extinctions. Flora moved south

Question 7

How is glaciation a driver for speciation?

Answer 7

1. glacial drift deposited earth and rocks, this changed the soil composition of much of Europe - therefore changing the vegetation
2. early glaciations covered the whole of Britain but last 3 didn’t
3. The last full glaciation left much of S England exposed - floral diversity boundaries
4. isolation - speciation

Question 8

Describe an example of how a hybrid species was caused by glaciation

Answer 8

Last ice age the plant Iris setosa pushed south to escape the glaciers

It moved into the territory of Iris virginica causing a hybridisation forming Iris versicolor

the glaciers then retreated north and the 2 got isolated again, but versicolor still persists