Post on 29-Dec-2015
Conservation of Hawaiian Drosophila using phylogenetic,
ecological and population genetic data.
Patrick M. O’Grady
University of California, Berkeley
Dr. Karl Magnacca
Richard Lapoint
Breeding ecology of the endemic Hawaiian Drosophilidae (Magnacca, Foote and O’Grady, Pacific Science)
Population genetics of a recently divergent group of Hawaiian Drosophila (Lapoint and O’Grady, P12)
– Estimating population genetic parameters (ancestral population size, migration rates, etc)
Outline
Phylogeny
Population Genetics
– Placement of the Hawaiian Drosophila & Scaptomyza– Time scale for drosophilid evolution– Ages of major Hawaiian lineages– Ecological associations
Introduction – Hawaiian Drosophila
Hawaiian Drosophila- 1,000 endemics
- diverse behavior & morphology
- single colonist?
- biogeography
- ancient: 25 mya
D.hanaulae
D.ingens
D.cyrtolomaD.melanocephala
D.obscuripes
D.neoperkinsi
D.oahuensis
D.nigribasis
D.neopicta
D.substenopteraD.hemipeza
D.silvestris
D.heteroneura
D.differens
D.planitibiaD.picticornis
D.setosifrons
D.primaeva
D.adunca
K
H
M
Mo
H
H
O
O
O
O
MN
Mo
EM
WM
WM
EM
EM
Habitat degradation (alien species, development, natural disaster, fire)
Pest control (insecticides, non-target effects)
Predation from alien arthropods (ants, wasps)
Competition (introduced Drosophila, Stratiomyidae, Neriidae)
Hawaiian Drosophilaand the genusScaptomyza
99
The Hawaiian Drosophilidae (genus Scaptomyza plus the Hawaiian Drosophila) form a clade. This is indicative of a single ancestral colonization event.
What group issister to the Hawaiian Drosophila?
How many colonizations of Hawaii?
51525354555
Colonization ofHawaii - 25my
multiple calibration points (fossils,biogeography)
How old are theendemic HawaiianDrosophilidae?
15my
16my
9my
21my
61
100
100
99
Species group relationships in Hawaiian Drosophila lineage agree with previous work.
100
antopocerus/modified tarsus
picture wing/nudidrosophila
modified mouthpart
haleakalae
Scaptomyza
99
10my
Phylogeny and Diversification Times
antopocerus/modified tarsus
picture wing/nudidrosophila
modified mouthpart
haleakalae
Scaptomyza
Araliaceae
Campanulaceae
Hawaiian Drosophilidae use ~40% (34/87) of native flowering plant families as larval substrates
Ecology
53
7
6
19
0 0
28 18
6 20
Araliaceae and Campanulaceae are used by nearly all major lineages
Loss of host plants via rarity or extinction
Endangered Hawaiian Drosophilidae
D. aglaia D. differens D. hemipeza D. heteroneura D. montgomeryi D. mulli D. musaphilia
D. neoclavisetae
D. obatai D. ochrobasis D. substenoptera
D. tarphytricha
picture wingconspicuousextensively studied
D. aglaia D. differens D. hemipeza D. heteroneura D. montgomeryi D. mulli D. musaphilia
D. neoclavisetae
D. obatai D. ochrobasis D. substenoptera
D. tarphytricha
– Taxonomy not well understood.– Difficult to work with (little known
of their ecology, not culturable in the laboratory, polytene chromosomes are not amenable to study).
– Historical distribution and abundance data not available.
Other groups?
Loss of host plants via rarity or extinction
D. aglaia D. differens D. hemipeza D. heteroneura D. montgomeryi D. mulli D. musaphilia
D. neoclavisetae
D. obatai D. ochrobasis D. substenoptera
D. tarphytricha
Endangered Hawaiian Drosophilidae
Drastic reduction in numbers of populations and population sizes.
once considered extinct; single population recently discovered
collected five times since 1975
collected frequently from 1967 -- 1975; not seen since 1986 historically known from 7 localities; only 1 population remainsextinct in part of historical range (Ko’olau Mountains)
known only from single, highly restricted localitiesknown only from single, highly restricted localities
Population Genetics
Population genetic techniques to estimate effective population size, Ne, of a given population
Drosophila neutralis
1,447,500
How large is a population? Is it small enough to be considered for conservation action? When should a very small population be considered inviable?
Laupohoehoe
Hawaii
Kau
Olaa
Stainback
670,414
1,442,708
2,605,417Ne ~ 6,000,000
Population Genetics
Population genetic techniques to estimate effective population size, Ne, of a given population
Rates of migration/gene flow
Coalescent theory to estimate ancestral population sizes
How large is a population? Is it small enough to be considered for conservation action? When should a very small population be considered inviable?
Does a species have a small population because it has (1) always been found in low numbers (rarity), (2) recently undergone a population decline (3) is the result of a founder event
Can we assess connectivity between proposed conservation management units?
D. neutralis
D. neutralis
D. dasycnemia
Ecological data is important when considering which taxa to target for conservation action. All taxa using a rare or endangered host plant may be at risk of population declines.
Conclusions
Knowledge of phylogeny, as well as the phylogenetic distribution of host plant use, can yield an appreciation for how many lineages (percentage of the total diversity) will be impacted by a decline in a given host plant.
Population genetic measures can be useful in the monitoring and evaluation of conservation decisions.
Population genetic techniques should be used before conservation management decisions are made to determine whether a population is truly in decline, and whether it is a viable candidate in which to invest limited resources.
Fungi (1)
Araliaceae (4)
Nyctaginaceae (3)
Campanulaceae (3)
Monocots (3) Sapindaceae (2)
Myrtaceae (1)
Other