+ Topic 4.5: On The Brink

+ What could “On the Brink” mean? The rate of extinctions recorded for animal and plant species in the last 400 years - Increased dramatically. Over 70 times higher than geological records Why should you care? It will impact you and future generations … other reasons?

+ Why are there so many extinctions? What are the greatest threats to species? Humans Land development (habitat destruction), introduction of alien species and pollution. What are some natural causes of extinction? Competition, disease, disappearance of food resources What can we do about it? In situ conservation sites: preserving the existing habitat Ex situ conservation: zoos and seedbanks Prevention: Stop/reduce destructive human activities

+ The role of zoos: pages Compare zoos now and the first zoos Purpose Animal treatment Read Animals in Zoos and Zoos: For and against in your handout packet. Write a summary of points for and against zoos.

+ Zoos ForAgainst Educates people, raises awareness, increases conservation support. Maintains numbers of animals, supports breeding programmes. Maintains genetic diversity via breeding programmes Enables scientific research, a better understanding of how to conserve. Entertains people. Unnatural habitat Limited space Unable to carry out normal behaviours Lack of social structures Animal may be unable to survive in the wild if released Animals exhibited on the basis of crowd pleasing rather than endangered status

+ What is the function of a zoo? Research into conservation of endangered species Captive breeding programmes Increase population numbers Reintroduce animals into wild Maintain genetic diversity Public education

+ Zoos – Centres for Scientific Research Research into the conservation of endangered species. Diet, behaviour, and the best ways to conserve the species. Working with locals to conserve habitat and reintroduce animals. Read pages194 and Answer A. This underground nest- building behaviour is selected for. The foam hides the eggs from predators and protects them from desiccation What kind of adaptation is this? B. Costs money to fly someone out there and provide food and accommodation Finding the nests would be difficult Hard not to disturb the frogs Takes time to liaise with local people

+ Captive Breeding Programmes What are the aims? 1. Increase numbers if numbers are low. 2. Maintain genetic diversity within captive population. 3. Reintroduce animals into the wild

+ Losing genetic variation Describe genetic drift By chance not all alleles are passed on, this causes a change in allele frequency over time. Take a look at page 195, picture 4.67 Genetic drift simulation- hill.com/sites/dl/free/ /126997/animation45.htmlhttp://highered.mcgraw- hill.com/sites/dl/free/ /126997/animation45.html When is genetic drift more likely to happen? Small populations

+ Losing genetic variation Describe inbreeding depression- page 196 Inbreeding causes– Frequency of homozygous genotypes to rise Frequency of heterozygotes decreases Accumulation of recessive alleles increases leading to less fit offspring (recessive alleles tend to be harmful) Can you think of examples?

+ Conserving genetic diversity Why is maintaining genetic diversity important? Need many different alleles in the population to provide variety in phenotype; If the environments changes (new selection pressure), population moves or a new disease emerges, it allows adaption. Successful breeding between wild and captive populations; How do zoos do this? Keep stud books which document the reproductive history and location of each animal. Activity 4.23, Animal Dating Agency

+ Reintroduce animals back into the wild – What are some of the problems when reintroducing animals back in the wild? Animals don’t have the necessary behaviours to find food fast enough and escape predators Their natural habits are not always intact How do zoos try to overcome these problems? “Hacking out”- gradually giving them more freedom and less food Read p198 Going, going … saved! & Q 4.35 Complete Activity 4.24 Putting them back

+ Q4.7 (page 198) Summarise the roles of zoos in the conservation of endangered species. Zoos undertake academic research into the conservation of the endangered species. The research may include work at the zoo or in the field on such topics as diet, behaviour, reproductive biology and the best ways to help conserve the species. Zoos may work, ideally with local people, on conservation projects in the species’ natural habitat. Such work is intended to help conserve the species in the wild, and includes reserve management. They undertake captive breeding programmes to increase the number of individuals of the species if numbers are very low. This helps to maintain genetic diversity within the captive population, and reintroduce animals to the wild if possible.

+ The Plant Perspective

+ Seed banks Read page Why do we need seed banks? Store of threatened plant species What can threaten plant species? Habitat destruction Climate change Overharvesting Man-made & natural disasters How can we conserve plants? In situ – protecting/managing habitats Ex situ – seed banks (help after disasters) Harvested Xate plants

+ Activity 4.25a Millennium Seed Bank Make a flow chart to summarise the processes involved in storage of seeds in a seed bank. Inspect for dryness and pests Dry in 15 degrees C and 15% humidity Clean- remove plant debris Separate healthy plants from the unhealthy ones- using air column and X-rays Dry again Store in dry room at – 20 degrees C Why are the seeds dried and stored at -20 degrees? To keep them for a long period of time, reducing metabolic rate To kill pests

+ Activity 4.25a Millennium Seed Bank Why are germination tests carried out? To test viability of seeds after all the treatment they have been though and stored a t -20 degrees. When very few seeds are viable then the viable seed are grown to produce adult plants and more seeds are collected. To find the optimum conditions for germination Why are international partnerships important? How can seed bank collections be used for research and education?

+ Checkpoint 4.7

+ The black-footed ferret story

+ Topic 4 Specification 17 Discuss and evaluate the methods used by zoos and seedbanks in the conservation of endangered species and their genetic diversity (e.g. scientific research, captive breeding programmes, reintroduction programmes and education).