conservation biology bisc 309 lecture 5 conservation ... · genetics (basics) - alleles,...

Conservation Biology BISC 309

Lecture 5

Conservation Genetics wrap-up

Course assessment - details

Do small populations have higher levels of inbreeding, reduced heterozygosity and lower levels of genetic variation? YES

Does inbreeding/loss of heterozygosity reduce a population’s ability to adapt? YES

What is the unresolved issue?

Evolution requires h2 = VA/VP Geneticists typically measure H and A

using neutral markers We don’t know if H predicts h2

How closely correlated are molecular and quantitative measures of genetic variation?

Reed and Frankham meta-analysis - 71 datasets mean corr r = 0.22 H and life history traits r = -0.11 ns H and morph traits r = 0.30

Molecular measures of variation provide a very imprecise measure of evolutionary potential

Next Q

How big do populations have to be to avoid losing genetic variation and the ability to adapt?

How big is big enough?

Franklin (1982) Argued VA determines evolutionary potential

VA at eqm depends on the balance between gain (mutation) and loss (drift)

Change VA = Vm - VA/2Ne

Require Ne when there is no change so 0 = Vm - VA/2Ne

Ne=VA/2Vm


Franklin (1982) used Vm=10-3VE Drosophila

Ne= VA/2(10-3.VE) = 500 VA/VE

since h2 = VA/VP ! VA/(VA+VE)

Ne = 500 h2/(1- h2)

if heritability 0.5 Need Ne = 500 -----> N = 5000 to avoid losing evolutionary potential

Q.why?


Retaining genetic diversity in perpetuity requires

Effective sizes of at least 500 Census population sizes of 5000

But how large are threatened populations?

Critically Endangered Threatened Endangered Criterion

Reduction in population size 10 yrs 3 generations

>80% >50% >30%

<100 km2 <5000 km2 <20,000 km2

<50 <250 <1000

>50% >20% >10% 10 yrs 20 yrs 100 yrs Or 3 gen or 5 gen

Small range

Very Small population

Quantitative analysis Eg PVA

IUCN

High profile threatened taxa

Giant panda 1000

Whooping crane 340

Mauna Kea silversword 500

Recovery targets for delisting

Black-footed ferret 1500 adults in 10 pop’ns Sea otter 2650

California condor 150 in 2 pop’ns + 150 captive Peregrine falcon 900 DELISTED in US

Red cockaded woodpecker 500 in 5 populations

Lakeside daisy 1000 plants

Target sizes are rarely based on genetic concerns

Summary

Population size influences evolutionary potential by reducing S, and reducing heritability (via loss of heterozygosity)

To retain evolutionary potential effective population sizes of 500 have been recommended ie 5000

Current pop’n sizes for most threatened spp in the wild or captivity are too small to avoid genetic deterioration

At this point you should now be able to:

Calculate Ne, H, F

Understand how/why Ne influences heterozygosity, inbreeding and evolutionary potential

Explain why it is important to conserve genetic variation

Discuss whether current recovery targets for endangered species are sufficient.

Genetics (basics) - alleles, heterozygosity, genetic drift, inbreeding, quantitative traits Evolutionary Analysis Fourth Edition

Conservation Genetics Ch 11. Principles of Conservation Biology (3rd Ed) Ch’s in Introduction to Conservation Genetics

Papers on Conservation Genetics Week 2 readings Week 3 readings ----- on course webpage

Assessment

Exams Midterm 20% or 15? Feb 18 Final 20% and 25? April 16

Tutorial Participation 5% Presentation 15%

Writing Newspaper article 15% Recovery Plan 25%

Goals of Presentation/Mini-lecture

1 to allow independent research relating to a current issue in conservation biology

2 to provide an opportunity for you to give a presentation in an informal setting

3! to increase the breadth of topics discussed during this course

4! to illustrate how scientific research is addressing conservation questions

Format of Presentation/Mini-lecture

2-3 presenters

10-12 minute presentation - powerpoint

3 minute discussion period

Content of Presentation/Mini-lecture

Topic - any conservation oriented issue (local, national, global)

TALK - introduce issue - identify key question or argument - give background - describe recent research ie one or two studies - what do new results mean

DISCUSSION- lead/prompt input from class - NOT a Q/Ans session

Goals of newspaper article

1 to allow independent research relating to a current issue in conservation biology

2! to develop the ability to communicate the importance and relevance of scientific research to a general audience

4! to increase awareness of conservation issues on campus

Format/content of Newspaper article

The article is to be written independently

Word limit 1000 words (minimum 500)

The article should be entertaining introduce why an issue is important describe the importance of recent research be critical and evaluate competing points of view identify the key sources of information

Getting started with the presentation/article

Finding a topic Sources of ideas your personal experience newspaper or magazine articles the internet scientific journals

Finding a topic - example 1 Cruising the scientific journals

Hunter 2007 Climate change and moving species: furthering the debate on assisted colonization. Conservation Biology 21: 1356-58

Issue: Climate change is likely to drive extinctions Possible Actions Increase connectivity to enhance movement Increase efforts to minimise climate change or Assisted colonization

Florida torreya

1000 trees left Decline linked to climate change - few new seeds are found

Proposed - assisted colonization Move spp. 500 km Northwards

--> southern Appalachians Not found there for 65 million years!


Garcia VB and others 2008 The importance of habitat and life history characters to extinction risk in sharks skates rays and chimaeras. Proc. R Soc Lond 275:83-89

Issue Deep water fisheries are seen as an alternative to depleted shallow water fisheries

40% Mediterranean sharks and rays threatened with extinction


Garcia VB and others 2008 The importance of habitat and life history characters to extinction risk in sharks skates rays and chimaeras. Proc. R Soc Lond 275:83-89

Question Do “slow” life histories of deep water species make them even more vulnerable to extinction?

Finding a topic - example 3 Cruising the internet

Science Daily Jan 14 2008 Greenhouse oceans may downsize fish, risking one of most productive fisheries

Bering Sea

diatoms --> large zooplankton ---> large fish

Produces 1/2 fish ct in US waters 1/3 fish ct worldwide

ISSUE

Greenhouse conditions favour small phytoplankton

---> change in food chain

---> reduced ability to soak up atmospheric CO2

Finding a topic - example 4 Cruising the internet

National Geographic News Jan 11 2008 Ants, Acacias drop truce when wildlife threat drops

Acacias provide “home” Ants protect against herbivores

What happens when large herbivores are lost from the system?

Finding a topic Reading the Newspaper - example 5

Guardian weekly - Too many elephants in the room Jan 4 2008

ISSUE - Elephants in SA

12,500 elephants in Kruger National Park

QUESTION

Is the large/growing population threatening the habitat of other species

Finding a topic Reading the Newspaper - example 5

Guardian weekly - Too many elephants in the room Jan 4 2008

Options

Resume culling

Translocations

Allow movement

Sterilization program

Q. How does sterilization influence male behavior and female fecundity?

Finding a topic - do this SOON

Developing your topic Read up on the basics Search for scientific articles by author or by topic Talk to people

Writing DUE FEB 27 5 pm Be engaging but provide context and more content and critical evaluation than in shorter media articles Get comments from friends/siblings/someone

Goals for the Recovery Strategy assignment

1.! To help understand the listing and recovery planning process in BC and Canada

2.!To practise using your scientific training to

collect data on a threatened spp

assess evidence for population declines

identify key threats to the species

identify critical habitat areas

suggest actions that will halt population declines and aid recovery

Format for the Recovery Strategy assignment

4 sections

Summary 250 words Background and Status 650 words Recovery Plan 1100 words Action Plan 1000 words

Plus references Figures


Summary - the bottom line in 250 words Background and Status Recovery Plan Action Plan


Summary Background and Status - distribution

- biology - population #, sizes - trends - significance - status

Recovery Plan Action Plan


Summary Background and Status Recovery Plan - scientific knowledge (gaps)

declining? Why? measurable objectives critical habitat (what/where) how could declines be halted rationale for approach

Action Plan


Summary Background and Status Recovery Plan Action Plan - who are the stakeholders

- does critical habitat need protection

- what legislation may be useful - socio-economic cost of spp loss of conservation actions

The Recovery strategy assignment

Getting started Finding a species

BC Ecosystem Species Explorer www.env.gov.bc.ca/atrisk/toolintro.html

! COSEWIC/SAR webpages

Your species may be listed or may be a candidate for assessment but can not have a published recovery plan

The Recovery strategy assignment

Further info on webpage Me - Guidelines for assignment CWS - Templates for Recovery Plans

Examples Real recovery strategies are on the SAR website

Questions about assignments in general

Your Input on assessment on workload on course

conservation biology bisc 309 lecture 5 conservation ... · genetics (basics) - alleles,...

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