Download - Evolution & Fisheries: A Relationship?: Dr. Malin Pinsky

Evolution on your dinner plate?

Malin Pinsky Ecology, Evolution, and Natural Resources

Institute of Marine and Coastal Sciences Rutgers University

The raw material for evolution

DNA

The raw material for evolution

DNA from Mother

from Father

Parts of the genome

Gene or locus

Parts of the genome

Allele

Source of variation

• Mutations

Source of variation

• Mutations

• Germ line copy passed to offspring

Oh cruel herb of soap, Bane of burritos worldwide, The slayer of taste.

from ihatecilantro.com

OR6A2 gene

People with two “soapy” alleles more likely than others (15% vs. 10%) to dislike cilantro

Eriksson et al. 2012 Flavour

Population

Population

• Allele frequencies –  50% blue –  50% red

Phenotype: running speed

Fast Slow

Phenotype: running speed

Fast Slow

Moderate

Population

• Fitness: ability to pass genes on to future generations

Population

• Fitness: ability to pass genes on to future generations

33% blue 67% red

Evolution

1.  Heritable variation

Evolution

1.  Heritable variation 2.  More offspring than can survive

Evolution

1.  Heritable variation 2.  More offspring than can survive 3.  Offspring vary in ability to survive

and reproduce

Bighorn sheep

Coltman et al. 2003 Nature

Bighorn sheep

down to thousands might have no effect on heterozygosity,but could result in a decline in allelic diversity [22]. Bycontrast, greater harvest of males through hunting inungulates could have limited effect on allelic diversitywhile reducing heterozygosity because NC (e.g. femalenumbers) can remain large even whenNe is reduced owingto increasingly skewed sex ratios favoring females [33].

The loss of genetic variation will also be influenced bygene flow among subpopulations that comprise a metapo-pulation. Estimating the effective population size of ametapopulation is extremely complex [34]. In addition,harvesting might have unexpected effects on the overallNe of a metapopulation. For example, Hindar and col-leagues have found that small subpopulations within ametapopulation of Atlantic salmon Salmo salar contributemore per spawner to the overall effective population sizethan large subpopulations, and harvesting of the subpopu-lations jointly in mixed-stock fisheries has a relativelylarger demographic effect on small than large populations[35].

Exploitative selectionSelective genetic changes within subpopulations resultingfrom exploitation are inevitable because increasingmortality will result in selection for earlier maturationeven if harvest is independent of phenotype [5]. Moreover,harvesting of wild populations is inevitably phenotypicallynonrandom [5]. That is, individuals of certain phenotypes(e.g. sizes or behaviors) are more likely than others to beremoved from a wild population by harvesting. Such se-lective harvest will bring about genetic changes in har-vested populations if the favored phenotype has at least apartial genetic basis (i.e. is heritable). In addition, suchchanges are likely to reduce both the frequency of desirablephenotypes (Box 2) and productivity.

We use the term ‘exploitative selection’ for the process ofselection resulting from human harvest. The term is ana-logous to ‘artificial selection’ used by Darwin for the inten-tional selection of certain traits in domestic animals andplants. Rapid genetic change in response to strong selec-tion has been called ‘contemporary evolution’ [36]. How-ever, this term can bemisleading because evolution ismorethan just change by natural selection. Thus, loss of geneticvariation caused by genetic drift or increase in geneticvariation caused by hybridization would also representcontemporary evolution.

The rate of genetic change by exploitative selectiondepends upon the amount of additive genetic variationfor the trait (heritability):

R ¼ HNS; [1]

where HN is the narrow-sense heritability, S is theselection differential (the difference in the phenotypicmeans between the selected parents and the whole popu-lation) and R is the response (the difference in thephenotypic means between the progeny generation andthe whole population in the previous generation) [32]. Inthe case of exploitative selection, S will be affected bothby the intensity of harvest (the proportion of the indi-viduals harvested) and the phenotypic selectivity of theharvest.

There aremany examples in the literature of phenotypicchanges in exploited populations thatmight be the result ofexploitative selection (Table 2). However, it has been diffi-cult to determine whether observed phenotypic changesover time indicate genetic change or are caused by otherfactors such as relaxing density-dependent effects ongrowth due to reductions in population density, or abioticfactors such as temperature affecting growth and devel-opment [37]. A recent review in this journal critically

Box 2. Effects of trophy hunting

Trophy hunting (and fishing) targets individuals with certaindesirable phenotypes [66]. The result is increased mortality andreduced fitness of those individuals with desirable phenotypes.Consequently, phenotypes that are considered desirable willdecrease in frequency. For example, populations of bighorn sheepOvis canadensis are often managed to provide a source of large-horned rams for trophy hunting [67]. In one population of bighornsheep at Ram Mountain, Alberta, Canada, a total of 57 rams wereharvested under such an unrestricted management regime over a30 year period [67]. This corresponded to an average harvest rate of"40% of the legal-sized rams in a given year, with the average age ofa ram at harvest of 6 years. Because rams in this population do notgenerally reach their peak reproductive years until 8 years of age[67], hunters imposed an artificial selection pressure on horn sizethat had the potential to bring about genetic change, provided thatthe horn size was heritable.

The heritability of horn size, or any other quantitative trait, can beestimated using pedigree information [60]. Mother–offspring rela-tionships in the Ram Mountain population were known throughobservation, and father–offspring relationships were determinedusing microsatellites for paternity and sibship analyses [67]. An‘animal model’ analysis (named as such because it estimates theexpected genetic ‘breeding value’ [twice the expected deviation ofan individual’s offspring from the term population mean for the traitbeing considered] for each individual animal in the population) wasconducted, which uses relatedness across the entire pedigree toestimate narrow-sense heritability. Horn length was found to behighly heritable (HN = 0.69) [67].

The examination of individual breeding values revealed that ramswith the highest breeding values were harvested earliest (Figure Ia)and therefore had lower fitness than rams of lower breeding value[67]. As a consequence, the average horn length observed in thepopulation has steadily declined (Figure Ib). Unrestricted harvestinghas therefore resulted in a decline in the trait that determines trophyquality (i.e. horn length) by removing desirable rams of high geneticquality before their reproductive peak.

Figure I. (a) Breeding value (twice the expected deviation of an individual’soffspring from the term population mean) for horn length of trophy-harvestedmale bighorn sheep at Ram Mountain. Males with greater breeding value areharvested at a younger age and thus tend to have lower fitness than males withlower breeding value [67]. (b) Plot of mean (#SE) horn length of 4-year-oldrams over a 30 year period showing the decline of mean horn length in thispopulation.

Review Trends in Ecology and Evolution Vol.23 No.6

331

Coltman et al. 2003 Nature

Fisheries effects

1957

Fisheries effects

1957 2007

Importance of diversity in populations


• Raw material for evolution



• “Insurance policy”



• “Insurance policy” • Avoid inbreeding

Measuring molecular diversity

• Number of alleles

Measuring molecular diversity

• Number of alleles • Heterozygosity

–  probability of picking two different alleles

Genetic bottlenecks

Alleles: 3 Heterozygosity: 60%

Genetic bottlenecks



Bottleneck examples

Robert Schwemmer

Northern elephant seal

Florida panther

Can fisheries cause bottlenecks?

Tuna, billfishes, swordfish Myers & Worm 2003 Nature

Purse seiner for salmon

Can fisheries cause bottlenecks?

Collapsed populations still abundant!

Num

ber o

f alle

les

(Ā) 12

11

10

9

8

71940 1960 1980 2000

A few examples?

New Zealand snapper (Pagrus auratus) after Hauser et al. 2002 PNAS

Peter Halasz

Num

ber o

f alle

les

(Ā) 12

11

10

9

8

71940 1960 1980 2000

A few examples?

Also: –  Atlantic

cod –  European

plaice


Peter Halasz

Num

ber o

f alle

les

(Ā) 12

11

10

9

8

71940 1960 1980 2000

A few examples?

Also: –  Atlantic

cod –  European

plaice

But not: –  Atlantic

cod –  Bluefin

tuna –  Canary

rockfish


Peter Halasz

Data

• Microsatellite diversity –  202 studies of 140 species

Available online at www.sciencedirect.com

Fisheries Research 89 (2008) 196–209

Stock identity of horse mackerel (Trachurus trachurus) in the Northeast

Atlantic and Mediterranean Sea: Integrating the results from

different stock identification approaches

P. Abaunza a,∗, A.G. Murta b, N. Campbell c, R. Cimmaruta d, A.S. Comesana e, G. Dahle f,

M.T. Garcıa Santamarıa g, L.S. Gordo h, S.A. Iversen f, K. MacKenzie c, A. Magoulas i,

S. Mattiucci j, J. Molloy k, G. Nascetti d, A.L. Pinto b, R. Quinta b, P. Ramos b,

A. Sanjuan e, A.T. Santos b, C. Stransky l, C. Zimmermann m

a Instituto Espanol de Oceanografıa, P.O. Box 240, 39080 Santander, Spain

b Instituto de Investigacao das Pescas e do Mar, Av. Brasilia, 1400 Lisboa, Portugal

c School of Biological Sciences (Zoology), The University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK

d Department of Ecology and Sustainable Economic Development, Tuscia University, Via S. Giovanni Decollato, 1, 01100 Viterbo, Italy

e Facultade de Bioloxıa, Edificio de Ciencias, Universidade de Vigo, E-36200 Vigo, Spain

f Institute of Marine Research, P.O. Box 1870, Nordnes, N-5817 Bergen, Norway

g Instituto Espanol de Oceanografıa, Avda. Tres de Mayo 73, 38005 Santa Cruz de Tenerife, Spain

h Facultade de Ciencias de Lisboa (IO/DBA), Bloco C-2, Campo Grande, 1749-016 Lisboa, Portugal

i Hellenic Centre for Marine Research, Institute of Marine Biology and Genetics, P.O. Box 2214, GR 710 013 Iraklio, Greece

j Department of Public Health Sciences, Section of Parasitology, “Sapienza” University of Rome, piazzale Aldo Moro n◦ 5, 00185 Rome, Italy

k The Marine Institute, Parkmore Industrial Estate, Galway, Ireland

l Bundesforschungsanstalt fur Fischerei, Institut fur Seefischerei, Palmaille 9, D-22767 Hamburg, Germany

m Bundesforschungsanstalt fur Fischerei, Institut fur Ostseefischerei, Alter Hafen Su 2, D-18069 Rostock, Germany

AbstractHorse mackerel stock identification was carried out with the aim of obtaining management units that were meaningful biological entities and

thus improving the management of the resource. The stock identification was made by integrating both established and innovative approaches such

as genetic markers (allozymes, mitochondrial DNA, microsatellite DNA and SSCP on nuclear DNA), morphometry, parasites as biological tags,

and life history traits (growth, reproduction and distribution), within the EU-funded HOMSIR project. The sampling covered almost the whole

distribution range of horse mackerel through 20 sampling localities in Northeast Atlantic and Mediterranean Sea. Horse mackerel showed low

levels of genetic differentiation, stable genetic structure over the study time and high levels of genetic variability. However, several approaches

(morphometrics and parasites) support the separation between the Atlantic Ocean and the Mediterranean Sea in horse mackerel populations,

although the most western Mediterranean area could also be mixed with the Atlantic populations. In the Northeast Atlantic, various stocks can be

distinguished mainly based on morphometrics, parasites and life history traits: a “southern” stock is distributed along the West Atlantic coast of

the Iberian Peninsula south to Cape Finisterre (NW Spain); a “western” stock, along the west coast of Europe from Cape Finisterre to Norway and

the “North Sea” stock. These results implied the revision of the boundaries of the southern and western stocks as previously defined. Results also

suggested that adult horse mackerel could migrate through different areas following the west coasts in the Northeast Atlantic (i.e. between Celtic

Seas and northern North Sea). Horse mackerel from the Mauritanian coast is distinguished by its high growth rate and high batch fecundity. Based

on the results from morphometric analysis and the use of parasites as biological tags, the horse mackerel population in the Mediterranean Sea is

sub-structured into at least three main areas: western, central and eastern Mediterranean. In this contribution, we have integrated the fundamental

findings of different approaches showing that the holistic approach is the appropriate way to identify horse mackerel stocks, on covering multiple

aspects of the biology of the species and reducing the type I error in stock identification.

© 2007 Elsevier B.V. All rights reserved.

Keywords: Trachurus trachurus; Stock identity; Holistic approach; Northeast Atlantic; Mediterranean Sea; Natural marks; Life history traits

∗ Corresponding author. Tel.: +34 942291060; fax: +34 942275072.

E-mail address: [email protected] (P. Abaunza).

0165-7836/$ – see front matter © 2007 Elsevier B.V. All rights reserved.

doi:10.1016/j.fishres.2007.09.022

Spatio-temporal populationstructuring and genetic

diversity retention in depleted Atlantic Bluefin tuna

of the Mediterranean Sea

Giulia Riccionia,1, Monica Landi

b,1,2, Giorgia Ferrarab, Ilaria Milano

b, Alessia Carianib, Lorenzo Zane

c, Massimo Sellad,3,

Guido Barbujania, and Fausto Tinti

b,4

aDepartment of Biologyand Evolution, Univ

ersity of Ferrara, 44100 Ferrara, Italy;

bDepartment of Experimental Evolution

ary Biology, University of Bologna,

40126 Bologna, Italy;cDepartment of Biology,

University of Padova, 35121 Padova, Italy; a

nd dInstitute Center for Marine Research, 52210 Rovinj, Croatia

(formerly Istituto Italo-Germanico di Biologia Marina/Deutsch-Italienisches Ins

titut für Meersbiologie, Rovigno, Italy)

Edited by Barbara Block, StanfordUniversity, Stan

ford, CA, and accepted by the Editorial BoardDecember 1, 2009 (received for review July 24, 2009)

Fishery genetics have greatly changed our understandingof

population dynamics and structuring in marine fish. In this study,

we show that theAtlantic Bluefin tuna (ABFT, Thu

nnus thynnus),an

oceanic predatory species exhibiting highly migratory behavior,

large population size, and high potential for dispersal during

early

life stages, displays significant ge

netic differences over space and

time, both at the fine and large scales of variation. We compared

microsatellite variationof contem

porary (n=256) andhistorical (n=

99) biological samples of ABFTs of the central-western Mediterra-

nean Sea, the latter dating back to the early 20th century.Measures

of genetic differentiationand a general hetero

zygote deficit sug-

gest that differences exist among population samples, both now

and 96–80 years ago. Thus, ABFTs do not represent a

single panmic-

tic population in theMediterranean Sea. Statistics designed to infer

changes in population size, both from current and past genetic var-

iation, suggest that some Mediterranean ABFT populations,

although still not severely reduced in their genetic po

tential, might

have suffered fromdemographic declines. The short-te

rmestimates

of effectivepopulation sizeare straddle

don theminimumthreshold

(effectivepopulationsize=500) indicatedt

omaintaingeneticdiver-

sity and evolutionary potential across several generations in

natural populations.

ancient DNA | effective population size | genetic structure | large pelagic

fishes | Thunnus thynnus

With an impressive amount of data accumulated in the last

10–15 years, genetic studies have greatly changed our

understanding of the ecology and evolution of marine fish pop-

ulations by showing evidence of complex genetic struc

ture at the

spatial and temporal scales of variation. This is esp

ecially true for

fish species with high mobility, high potential for dispersal during

egg and larval stages, andlarge population sizes (1, 2). Accurate

estimates of genetic variation in fish populations, both

for neutral

and adaptive loci, can also suggest unique strategies for stock

management and conservation of evolutionary potential in

severely exploited fishery resources (3–5). The assessment of

population dynamics, environmentally driven changes, and levels

of exploitation in large pelagic fish is crucial for bothstock man-

agement and conservation of marine ecosystems dominated by

these oceanic toppredators (6). Although fisheries s

till remain the

chief source of data for assessing spatiotemporal population

dynamics of these fish (7–10), wheneverpossible, their findings

shouldbe comparedwith thoseoffishery-independ

ent approaches,

such as genetic, electronic, andmicrochemical tagging experi

ments

(11–13), to have more accurate data on the key features of pop-

ulation dynamics, such as spawning and migrations (10).

The Atlantic Bluefin tuna (ABFT, Thunnus thynnus) is a large

top-predator fishexploiting the pelagic ecosystems of the North

Atlantic Ocean andMediterranean Sea.Much like the other

large

tunas, the ABFT displays highly migratory behavior, with docu-

mented transoceanic andlarge-scale movements for feeding and

reproduction, high fecundity, and high mortality of larval stages

(reviewed in 14, 15). Nonetheless, tagging experiments and fish-

ery data analyses have unraveled an unexpected and complex

interplay of ecological, behavioral,

and reproductive factors that

could affect the spatial and temporal populationdynamics at the

large scale (11, 16). Microchemical signatures in otoliths of

yearlings (i.e., young-of-the-year) unequivocally identified two

main spawning areas [i.e., the Mediterranean Sea for the Easte

rn

Atlantic population, the Gulf of Mexico for the Western Atlantic

population (13)]. Because of high rates of natal homing of

spawning adults to their native areas (95.8% for the Medi-

terranean Sea and 99.3% for the Gulf of Mexico) and limited and

more complex movements in sexually mature ABFTs (11, 17), the

two populations show significant genetic divergence at both

microsatellite (12) and mtDNA (18) loci. The two ABFT pop-

ulations differ insize, with the eastern population approximately

10 times as large as the western population (19). Both are suf-

fering from overfishing and are considered depleted, consistent

with the continuous decline of the spawning stock biomass

(which, in the eastern stock, is now at 40% of the 1970s levels),

with the high fishing mortality rate of age class 8 and older indi-

viduals, and with modeling predictions (16, 19, 20).

The complex population dynamics exhibited by ABFTs at the

large scale is also apparent at a finer scale in the Mediterranean

Sea (16). Size-dependent movements and spawning in different

areas and periods have been documented (15, 21–23). Genetic

variation among three geographical samples suggested that at

least two subpopulations inhabit and persist over short time

periods (3 years) in the western and eastern Mediterranean Sea,

yielding Wright’s genetic variance (FST) values within the Med-

iterranean Sea between 0.0007 and 0.0087 (12, 24). In this study,

we started from a more thorough sampling of Mediterranean

ABFTs in space and time. Along with an extensive spatial sam-

pling of contemporary ABFTs carried out from 1999 to 2007 in

the central-western Mediterranean (CWM), we also had access

to historical ABFT specimens collected by one of the authors

(M.S.) in the CWM tuna traps between 1911 and 1926 (Fig. S1).

Author contributions: M.L., G.B, and F.T. designed research; M.L., G.F., I.M., A.C., and M.S.

performed research; G.R.,M.L., G.F., and L.Z. analyzed data; and G.R., G.F., L.Z.,

G.B, and

F.T. wrote the paper.

The authors declareno conflict of inte

rest.

This article is a PNAS Direct Submission. B.B. is a guest editor inv

ited by the Editorial Board.

1G.R. and M.L. contributedequally to this work.

2Present address: Department of Biology,

University of Minho, Campus de Gualtar, 4710–

057 Braga, Portugal.

3Deceased April 9, 1959.

4To whom correspondenceshould be addressed at: Department of Experim

ental Evolu-

tionary Biology, University of Bologna, via

Selmi 3, 40126 Bologna, Italy.E-mail: fausto.

[email protected].

This article contains supporting information online at www.pnas.org/cgi/content/full/

0908281107/DCSupplemental.

2102–2107 | PNAS | February 2, 2010 | vol. 107 | no. 5

www.pnas.org/cgi/doi/10.1073/pnas.

0908281107

TECHNICAL NOTE

Isolation and characterization of microsatellite markers

for the heavily exploited rockfish Sebastes schlegeli,

and cross-species amplification in four related Sebastes spp.

Hye Suck An Æ Jung Youn Park Æ Mi-Jung Kim Æ

Eun Young Lee Æ Kyung Kil Kim

Received: 19 February 2009 / Accepted: 24 February 2009 / Published online: 7 March 2009

! Springer Science+Business Media B.V. 2009

Abstract Here we report development and characteriza-

tion of 14 polymorphic microsatellite loci from Sebastes

schlegel. Polymorphism at these loci revealed from 3 to 23

alleles. The observed heterozygosity ranged from 0.34 to

1.00, and the expected heterozygosity ranged from 0.31 to

0.95. No linkage disequibrium was found. Two loci were

significantly deviated from HWE (P\ 0.01). The 14 loci

were also surveyed in four other Sebastes species and 12

loci successfully amplified, where allelic diversity ranged

from highly polymorphic to monomorphic. These results

demonstrate these microsatellite markers can be used for

the study of intra- and inter-specific genetic diversity.

Keywords Sebastes schlegel ! Rockfish !

Microsatellites markers ! Cross-amplification

Introduction

Rockfish Sebastes schlegeli, belonging to the family

Sebastinae and an important commercial fish in Korea, is

one of the species for which artificial reproduction and

cultivation have intensively been made throughout Korean

coastal areas to increase the harvest yield since the early

1990s. A stock enhancement program through the release

of hatchery-raised juveniles into natural environments has

been practiced since the middle 1990s. In 2007, approxi-

mately two million seeds were released. In stock

enhancement programs, the genetic characterization of the

stocking species used should be assessed in view of

elucidating and monitoring the effect of such activities on

wild stocks (FAO 1993). Therefore, in recent years, the

extent of stocking impacts upon indigenous populations has

been a focus of attention from viewpoints of conservation

and management for this species. However, to date little is

known about genetic diversity and population differentia-

tion of this species. Information regarding population

structure, levels of geneflow and genetic diversity within

and among populations of species harvested for com-

mercial purposes can provide useful information for

developing conservation and management plans.

Although six microsatellite markers from S. schlegeli

have been already reported by Yoshida et al. (2005), a set

of molecular markers are needed for various other appli-

cations, from further population studies to pedigree

analysis. In this work, we isolated 14 novel microsatellite

markers from S. schlegeli, and represented their evaluation

for cross-species amplification in four other related con-

generic species.

We developed a partial genomic library enriched for CA

repeats as described in the protocol of Hamilton et al.

(1999) with a slight modification using prehybridization

PCR amplification (Gardner et al. 1999). Genomic DNA

was extracted from each fin tissue sample of S. schlegel

captured in western coast of Korea using TNES-Urea

buffer method (Asahida et al. 1996). DNA was simulta-

neously digested with restriction enzymes AluI, RsaI, NheI

and HhaI (New England Biolabs, Bervery, MA, USA).

DNA fragments ranging from 300 to 800 bp were isolated

and ligated to double-stranded linker-adapted primers

(SNX/SNX rev linker sequences). Linker-ligated DNA

fragments were then amplified using single-stranded linker-

adapted primer (SNX) as polymerase chain reaction

primer. Biotinylated dinucleotide repeat sequences [50-

(CA)12GCTTGA-biotin (Li et al. 2002)] were hyb

ridized toH. S. An (&) ! J. Y. Park ! M.-J. Kim ! E. Y. Lee ! K. K. Kim

Biotechnology Research Institute, National Fisheries Research

and Development Institute, Busan 619-705, Korea

e-mail: [email protected]

123

Conserv Genet (2009) 10:1969–1972

DOI 10.1007/s10592-009-9870-8

Demogr

aphic his

tory, g

eograp

hical d

istrib

ution

andrep

roduct

ive

isolat

ionof

distin

ctline

ages of

blue roc

kfish (Se

bastes

mystinu

s),

a marine

fishwith

a high dis

persal

potent

ial

M. O. B

URFO

RD

Departm

entof E

cology

andEvo

lutiona

ry Biolo

gy,Un

iversity

of Calif

ornia San

ta Cruz, S

anta Cru

z, CA,

USA

Introd

uction

Conte

mporary

andevo

lution

arytim

e-scal

e factor

s such

ascur

rent or

wind

patter

ns,geo

graphi

calbar

riers,

demogr

aphic

charac

teristi

cs,phy

sical cha

nges in

the

enviro

nment

, or a

combin

ation of

these

factor

s can

act

tored

ucegen

e flowam

ongpop

ulation

s throug

hout a

specie

s’ rang

e (Avise,

1994).

Inmarin

e system

s, redu

c-

tionor

elimina

tionin

gene flow

maylea

d togen

etic

differe

ntiatio

n orspe

ciation

even wit

hinspe

cies wit

h

long p

elagic

stages

, espec

ially if

popula

tions ar

e separ

ated

into diff

erent

ecolog

ical re

gions.

Select

ivefor

cescan

also

lead to

genetic

structu

reor

specia

tionin

marine tax

a

with a lon

g pelagi

c stage

only if i

t isstro

ngeno

ughto

counte

ract the

homoge

nizing

effect

ofgen

e flow. T

he

evalua

tionof t

hegen

eticrela

tionshi

p among

popula

tions

ordis

tinct

lineage

s inare

aswh

erediv

ergent

lineage

s

overlap

andwh

ereonl

y one

lineage

is foun

d can

improve

ourun

dersta

nding

of the

evolut

ionary

forces

andeve

nts

causin

gspe

ciation

inthe

marine

enviro

nment

. For

example

, high

potent

ialdis

persal

maynot

transl

ateto

high lev

elsof

realize

d gene flow

. We mayalso

gain

insigh

t into

why

there

ishig

hspe

cies div

ersity

in

taxono

mic grou

pswit

h high dis

persal

potent

ial.

Althou

ghthe

rockfis

hes(Sc

orpaen

idae:

Sebaste

s)are

consid

ered a

n ancien

t speci

es flock

(John

s &Av

ise,199

8)

with a hig

h potent

ialfor

disper

sal(th

rough

a pelagi

c

stage

lasting

2–5mont

hs;Lov

e et al.,

2002),

there

is

eviden

ceof

recent

specia

tionwit

hinthe

genus.

Rocha

-

Olivar

eset a

l. (199

9a)fou

ndrec

entspe

ciation

betwe

en

sister-

taxa in

thesub

genus

Sebasto

mus. T

woinv

estiga

-

tions wit

hinroc

kfish

specie

s found

cryptic

specia

tion

within

vermilio

n rockfis

h (Sebas

tesmin

iatus)

that wa

s

caused

bydiff

erence

indep

thdis

tributi

on(Hy

deet a

l.,

2008)

anda sim

ilarpat

tern of

sympat

ricdis

tributi

onof

distin

ctgen

eticpop

ulation

s ofPac

ificoce

anper

ch

Corresp

ondenc

e: Mart

haO.

Burfo

rd,208

Fernow

Hall, C

ornell

Unive

rsity,

Ithaca

, NY 148

53,US

A.

Tel.: +

1 831419

7586; f

ax:+1

831459

3383; e

-mail:

mob8@c

ornell.

edu

ª 2 009

THE AU

THOR . J

. EVO

L .B I O

L .2 2

( 2 00 9

) 14 7

1 –1 4

86

JOURNAL

COMP I LA T

I ON ª 2009

EUROPE

ANSO

C I E TY FO

R EVOLU

T IONAR

Y B IO LOGY

1471

Keywor

ds:

admixtu

re;

assign

menttes

t;

microsat

ellite loc

i;

mismatc

h distrib

ution;

mtDNA con

trol re

gion;

popula

tionexp

ansion

;

reprod

uctive

isolati

on;

specia

tion.

Abstr

act

Under

standi

ngthe

barrier

s togen

eticexc

hange

in taxono

mic grou

ps that

have

a high dis

persal

potent

ialwil

l prov

idecrit

ical in

formatio

n onspe

ciation

in

genera

l. Blue

rockfis

h (Sebas

tesmy

stinus)

aregoo

d taxa to

examine

specia

tion

becaus

e they are

nonmigra

tory inh

abitan

tsof

shallow

rocky

reef hab

itats

along

theeas

tern No

rthPac

ificwit

h a pela

giclarv

al stag

e lastin

g 3–5

months.

Thegoa

l ofthi

s study

was to

analyse

theevo

lution

aryhis

tory a

nddis

tributi

on

patter

nsof

differe

ntline

ages w

ithin

S. mysti

nusdes

cribed

previo

usly and

use

this in

formatio

n toun

dersta

ndthe

specia

tionpro

cess in

this g

roup of

high

disper

salfish

. Themole

cular

data der

ived fro

mspe

cimens

sample

d over

approx

imately

1650 km

ofthe

S.my

stinus

range

reveal

eda nor

therly

and

southe

rlydis

tributi

onfor

thetwo

lineage

s. Almost

equal f

requen

cies o

f both

lineage

s occurr

edat

centra

llyloc

ated sam

pleloc

ations,

with evi

dence

of

reprod

uctive

isolati

onbet

ween

theline

ages. A

demogr

aphic a

nalysis

showe

d

that th

e two line

ages d

iverge

d andexp

erience

d sudden

expans

ionpri

orto the

lastgla

cial maxi

mum, wh

ichaffe

cted

theobs

erved

patter

nof

genetic

structu

re.The

spatial

distrib

ution,

demogr

aphic h

istory

anddeg

reeof g

enetic

distin

ctivene

ss foun

d from

thegen

eticana

lysis, d

espite

thehig

h potent

ialfor

disper

salin

S. mysti

nus, su

ggest b

othline

ages d

iverge

d inallo

patry.

doi: 10

.1111/

j.1420-

9101.2

009.01

760.x

Mar BiolDOI 10.1007/s00227-010-1419-3

123

ORIGINAL PAPER

Life history, ecology and the biogeography of strong genetic breaks among 15 species of PaciWc rockWsh, SebastesArjun Sivasundar · Stephen R. Palumbi

Received: 15 April 2009 / Accepted: 2 March 2010© Springer-Verlag 2010

Abstract Strong genetic change over short spatial scalesis surprising among marine species with high dispersalpotential. Concordant breaks among several species signalsa role for geographic barriers to dispersal. Along the coastof California, such breaks have not been seen across thebiogeographic barrier of Point Conception, but other poten-tial geographic boundaries have been surveyed less often.We tested for strong-population structure in 11 species ofSebastes sampled across two regions containing potentialdispersal barriers, and conducted a meta-analysis includingfour additional species. We show two strong breaks northof Monterey Bay, spanning an oceanographic gradient andan upwelling jet. Moderate genetic structure is just as com-mon in the north as it is in the south, across the biogeo-graphic break at Point Conception. Gene Xow is generallyhigher among deep-water species, but these conclusions areconfounded by phylogeny. Species in the subgenus Sebast-osomus have higher structure than those in the subgenusPteropodus, despite having larvae with longer pelagicphases. DiVerences in settlement behavior in the face ofocean currents might help explain these diVerences. Acrosssimilar species across the same coastal environment, we

document a wide variety of patterns in gene Xow, suggest-ing that interaction of individual species traits such assettlement behavior with environmental factors such asoceanography can strongly impact population structure.

Introduction

For many marine species, larval dispersal is a critical partof migration ability, and life history diVerences betweenspecies can dramatically aVect gene Xow. Investigations ofgenetic diVerences among marine populations have beenwidely used to gauge levels of dispersal, which often scalewith larval traits such as pelagic duration (e.g. Berger 1973;Bohonak 1999; Marko 2004). Species for which larvalduration is short or absent have often been found to havestrong genetic structure among invertebrates (McMillanet al. 1992; Hellberg 1994, 1996) and Wshes (e.g. Waples1987; Doherty et al. 1995; Riginos 2001; Purcell et al.2006). However, unexpectedly strong structure has alsobeen demonstrated for some species that are presumed tohave long distance dispersal potential (e.g. Reeb et al.2000; Barber et al. 2002; Burford and Bernardi 2008).Uncovering the reasons for strong genetic breaks in suchspecies can potentially reveal a great deal about larvalmechanisms that limit dispersal.Some of the clearest explanations of strong geneticbreaks derive from the observation that in some cases, thesebreaks are concordant with strong biogeographic bound-aries. Taxa as diverse as coastal birds, tortoises, Wsh andinvertebrates show strong geographic diVerentiation alongthe southeastern coast of the United States (Avise 1992,1996). Other cases of the conXuence of genetic and biogeo-graphic breaks in the oceans have been found in Indonesia,the western Mediterranean, the East PaciWc and the Red Sea

Communicated by M. I. Taylor.A. Sivasundar · S. R. PalumbiDepartment of Biological Sciences, Hopkins Marine Station, Stanford University, 120 Oceanview Boulevard, PaciWc Grove, CA 93950, USA

A. Sivasundar (&)Division of Aquatic Ecology, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerlande-mail: [email protected]

National Oceanic and Atmospheric Administration

Data


–  Number of alleles (A)













































doi:10.1016/j.fishres.2007.09.022









b,4















nnus thynnus),an



early









zygote deficit sug-



single panmic-





tential, might


rmestimates













ture at the


ecially true for




for neutral








till remain the




ent approaches,


ments






large












rn
































G.B, and



rest.









ental Evolu-



[email protected].





0908281107

TECHNICAL NOTE






















Introduction






























generic species.





















123

Conserv Genet (2009) 10:1969–1972

DOI 10.1007/s10592-009-9870-8

Demogr

aphic his

tory, g

eograp

hical d

istrib

ution

andrep

roduct

ive

isolat

ionof

distin

ctline

ages of

blue roc

kfish (Se

bastes

mystinu

s),

a marine

fishwith

a high dis

persal

potent

ial

M. O. B

URFO

RD

Departm

entof E

cology

andEvo

lutiona

ry Biolo

gy,Un

iversity

of Calif

ornia San

ta Cruz, S

anta Cru

z, CA,

USA

Introd

uction

Conte

mporary

andevo

lution

arytim

e-scal

e factor

s such

ascur

rent or

wind

patter

ns,geo

graphi

calbar

riers,

demogr

aphic

charac

teristi

cs,phy

sical cha

nges in

the

enviro

nment

, or a

combin

ation of

these

factor

s can

act

tored

ucegen

e flowam

ongpop

ulation

s throug

hout a

specie

s’ rang

e (Avise,

1994).

Inmarin

e system

s, redu

c-

tionor

elimina

tionin

gene flow

maylea

d togen

etic

differe

ntiatio

n orspe

ciation

even wit

hinspe

cies wit

h

long p

elagic

stages

, espec

ially if

popula

tions ar

e separ

ated

into diff

erent

ecolog

ical re

gions.

Select

ivefor

cescan

also

lead to

genetic

structu

reor

specia

tionin

marine tax

a

with a lon

g pelagi

c stage

only if i

t isstro

ngeno

ughto

counte

ract the

homoge

nizing

effect

ofgen

e flow. T

he

evalua

tionof t

hegen

eticrela

tionshi

p among

popula

tions

ordis

tinct

lineage

s inare

aswh

erediv

ergent

lineage

s

overlap

andwh

ereonl

y one

lineage

is foun

d can

improve

ourun

dersta

nding

of the

evolut

ionary

forces

andeve

nts

causin

gspe

ciation

inthe

marine

enviro

nment

. For

example

, high

potent

ialdis

persal

maynot

transl

ateto

high lev

elsof

realize

d gene flow

. We mayalso

gain

insigh

t into

why

there

ishig

hspe

cies div

ersity

in

taxono

mic grou

pswit

h high dis

persal

potent

ial.

Althou

ghthe

rockfis

hes(Sc

orpaen

idae:

Sebaste

s)are

consid

ered a

n ancien

t speci

es flock

(John

s &Av

ise,199

8)

with a hig

h potent

ialfor

disper

sal(th

rough

a pelagi

c

stage

lasting

2–5mont

hs;Lov

e et al.,

2002),

there

is

eviden

ceof

recent

specia

tionwit

hinthe

genus.

Rocha

-

Olivar

eset a

l. (199

9a)fou

ndrec

entspe

ciation

betwe

en

sister-

taxa in

thesub

genus

Sebasto

mus. T

woinv

estiga

-

tions wit

hinroc

kfish

specie

s found

cryptic

specia

tion

within

vermilio

n rockfis

h (Sebas

tesmin

iatus)

that wa

s

caused

bydiff

erence

indep

thdis

tributi

on(Hy

deet a

l.,

2008)

anda sim

ilarpat

tern of

sympat

ricdis

tributi

onof

distin

ctgen

eticpop

ulation

s ofPac

ificoce

anper

ch

Corresp

ondenc

e: Mart

haO.

Burfo

rd,208

Fernow

Hall, C

ornell

Unive

rsity,

Ithaca

, NY 148

53,US

A.

Tel.: +

1 831419

7586; f

ax:+1

831459

3383; e

-mail:

mob8@c

ornell.

edu

ª 2 009

THE AU

THOR . J

. EVO

L .B I O

L .2 2

( 2 00 9

) 14 7

1 –1 4

86

JOURNAL

COMP I LA T

I ON ª 2009

EUROPE

ANSO

C I E TY FO

R EVOLU

T IONAR

Y B IO LOGY

1471

Keywor

ds:

admixtu

re;

assign

menttes

t;

microsat

ellite loc

i;

mismatc

h distrib

ution;

mtDNA con

trol re

gion;

popula

tionexp

ansion

;

reprod

uctive

isolati

on;

specia

tion.

Abstr

act

Under

standi

ngthe

barrier

s togen

eticexc

hange

in taxono

mic grou

ps that

have

a high dis

persal

potent

ialwil

l prov

idecrit

ical in

formatio

n onspe

ciation

in

genera

l. Blue

rockfis

h (Sebas

tesmy

stinus)

aregoo

d taxa to

examine

specia

tion

becaus

e they are

nonmigra

tory inh

abitan

tsof

shallow

rocky

reef hab

itats

along

theeas

tern No

rthPac

ificwit

h a pela

giclarv

al stag

e lastin

g 3–5

months.

Thegoa

l ofthi

s study

was to

analyse

theevo

lution

aryhis

tory a

nddis

tributi

on

patter

nsof

differe

ntline

ages w

ithin

S. mysti

nusdes

cribed

previo

usly and

use

this in

formatio

n toun

dersta

ndthe

specia

tionpro

cess in

this g

roup of

high

disper

salfish

. Themole

cular

data der

ived fro

mspe

cimens

sample

d over

approx

imately

1650 km

ofthe

S.my

stinus

range

reveal

eda nor

therly

and

southe

rlydis

tributi

onfor

thetwo

lineage

s. Almost

equal f

requen

cies o

f both

lineage

s occurr

edat

centra

llyloc

ated sam

pleloc

ations,

with evi

dence

of

reprod

uctive

isolati

onbet

ween

theline

ages. A

demogr

aphic a

nalysis

showe

d

that th

e two line

ages d

iverge

d andexp

erience

d sudden

expans

ionpri

orto the

lastgla

cial maxi

mum, wh

ichaffe

cted

theobs

erved

patter

nof

genetic

structu

re.The

spatial

distrib

ution,

demogr

aphic h

istory

anddeg

reeof g

enetic

distin

ctivene

ss foun

d from

thegen

eticana

lysis, d

espite

thehig

h potent

ialfor

disper

salin

S. mysti

nus, su

ggest b

othline

ages d

iverge

d inallo

patry.

doi: 10

.1111/

j.1420-

9101.2

009.01

760.x

Mar BiolDOI 10.1007/s00227-010-1419-3

123

ORIGINAL PAPER





Introduction





Data


–  Number of alleles (A)

–  Heterozygosity (He)













































doi:10.1016/j.fishres.2007.09.022









b,4















nnus thynnus),an



early









zygote deficit sug-



single panmic-





tential, might


rmestimates













ture at the


ecially true for




for neutral








till remain the




ent approaches,


ments






large












rn
































G.B, and



rest.









ental Evolu-



[email protected].





0908281107

TECHNICAL NOTE






















Introduction






























generic species.





















123

Conserv Genet (2009) 10:1969–1972

DOI 10.1007/s10592-009-9870-8

Demogr

aphic his

tory, g

eograp

hical d

istrib

ution

andrep

roduct

ive

isolat

ionof

distin

ctline

ages of

blue roc

kfish (Se

bastes

mystinu

s),

a marine

fishwith

a high dis

persal

potent

ial

M. O. B

URFO

RD

Departm

entof E

cology

andEvo

lutiona

ry Biolo

gy,Un

iversity

of Calif

ornia San

ta Cruz, S

anta Cru

z, CA,

USA

Introd

uction

Conte

mporary

andevo

lution

arytim

e-scal

e factor

s such

ascur

rent or

wind

patter

ns,geo

graphi

calbar

riers,

demogr

aphic

charac

teristi

cs,phy

sical cha

nges in

the

enviro

nment

, or a

combin

ation of

these

factor

s can

act

tored

ucegen

e flowam

ongpop

ulation

s throug

hout a

specie

s’ rang

e (Avise,

1994).

Inmarin

e system

s, redu

c-

tionor

elimina

tionin

gene flow

maylea

d togen

etic

differe

ntiatio

n orspe

ciation

even wit

hinspe

cies wit

h

long p

elagic

stages

, espec

ially if

popula

tions ar

e separ

ated

into diff

erent

ecolog

ical re

gions.

Select

ivefor

cescan

also

lead to

genetic

structu

reor

specia

tionin

marine tax

a

with a lon

g pelagi

c stage

only if i

t isstro

ngeno

ughto

counte

ract the

homoge

nizing

effect

ofgen

e flow. T

he

evalua

tionof t

hegen

eticrela

tionshi

p among

popula

tions

ordis

tinct

lineage

s inare

aswh

erediv

ergent

lineage

s

overlap

andwh

ereonl

y one

lineage

is foun

d can

improve

ourun

dersta

nding

of the

evolut

ionary

forces

andeve

nts

causin

gspe

ciation

inthe

marine

enviro

nment

. For

example

, high

potent

ialdis

persal

maynot

transl

ateto

high lev

elsof

realize

d gene flow

. We mayalso

gain

insigh

t into

why

there

ishig

hspe

cies div

ersity

in

taxono

mic grou

pswit

h high dis

persal

potent

ial.

Althou

ghthe

rockfis

hes(Sc

orpaen

idae:

Sebaste

s)are

consid

ered a

n ancien

t speci

es flock

(John

s &Av

ise,199

8)

with a hig

h potent

ialfor

disper

sal(th

rough

a pelagi

c

stage

lasting

2–5mont

hs;Lov

e et al.,

2002),

there

is

eviden

ceof

recent

specia

tionwit

hinthe

genus.

Rocha

-

Olivar

eset a

l. (199

9a)fou

ndrec

entspe

ciation

betwe

en

sister-

taxa in

thesub

genus

Sebasto

mus. T

woinv

estiga

-

tions wit

hinroc

kfish

specie

s found

cryptic

specia

tion

within

vermilio

n rockfis

h (Sebas

tesmin

iatus)

that wa

s

caused

bydiff

erence

indep

thdis

tributi

on(Hy

deet a

l.,

2008)

anda sim

ilarpat

tern of

sympat

ricdis

tributi

onof

distin

ctgen

eticpop

ulation

s ofPac

ificoce

anper

ch

Corresp

ondenc

e: Mart

haO.

Burfo

rd,208

Fernow

Hall, C

ornell

Unive

rsity,

Ithaca

, NY 148

53,US

A.

Tel.: +

1 831419

7586; f

ax:+1

831459

3383; e

-mail:

mob8@c

ornell.

edu

ª 2 009

THE AU

THOR . J

. EVO

L .B I O

L .2 2

( 2 00 9

) 14 7

1 –1 4

86

JOURNAL

COMP I LA T

I ON ª 2009

EUROPE

ANSO

C I E TY FO

R EVOLU

T IONAR

Y B IO LOGY

1471

Keywor

ds:

admixtu

re;

assign

menttes

t;

microsat

ellite loc

i;

mismatc

h distrib

ution;

mtDNA con

trol re

gion;

popula

tionexp

ansion

;

reprod

uctive

isolati

on;

specia

tion.

Abstr

act

Under

standi

ngthe

barrier

s togen

eticexc

hange

in taxono

mic grou

ps that

have

a high dis

persal

potent

ialwil

l prov

idecrit

ical in

formatio

n onspe

ciation

in

genera

l. Blue

rockfis

h (Sebas

tesmy

stinus)

aregoo

d taxa to

examine

specia

tion

becaus

e they are

nonmigra

tory inh

abitan

tsof

shallow

rocky

reef hab

itats

along

theeas

tern No

rthPac

ificwit

h a pela

giclarv

al stag

e lastin

g 3–5

months.

Thegoa

l ofthi

s study

was to

analyse

theevo

lution

aryhis

tory a

nddis

tributi

on

patter

nsof

differe

ntline

ages w

ithin

S. mysti

nusdes

cribed

previo

usly and

use

this in

formatio

n toun

dersta

ndthe

specia

tionpro

cess in

this g

roup of

high

disper

salfish

. Themole

cular

data der

ived fro

mspe

cimens

sample

d over

approx

imately

1650 km

ofthe

S.my

stinus

range

reveal

eda nor

therly

and

southe

rlydis

tributi

onfor

thetwo

lineage

s. Almost

equal f

requen

cies o

f both

lineage

s occurr

edat

centra

llyloc

ated sam

pleloc

ations,

with evi

dence

of

reprod

uctive

isolati

onbet

ween

theline

ages. A

demogr

aphic a

nalysis

showe

d

that th

e two line

ages d

iverge

d andexp

erience

d sudden

expans

ionpri

orto the

lastgla

cial maxi

mum, wh

ichaffe

cted

theobs

erved

patter

nof

genetic

structu

re.The

spatial

distrib

ution,

demogr

aphic h

istory

anddeg

reeof g

enetic

distin

ctivene

ss foun

d from

thegen

eticana

lysis, d

espite

thehig

h potent

ialfor

disper

salin

S. mysti

nus, su

ggest b

othline

ages d

iverge

d inallo

patry.

doi: 10

.1111/

j.1420-

9101.2

009.01

760.x

Mar BiolDOI 10.1007/s00227-010-1419-3

123

ORIGINAL PAPER





Introduction





Paired comparisons

Overfished populations

Healthy species and population in same genus or family

Pinsky et al. 2014 Molecular Ecology

Paired comparisons

Pinsky et al. 2014 Molecular Ecology

Other Pagrus

New Zealand snapper (Pagrus auratus)

A = 16 He = 0.7 A = 12 He = 0.8

Paired comparisons overfished vs. control

n = 12

A50 = 10.2He = 0.736

A50 = 16.6He = 0.846

A50 = 10.2He = 0.736

A50 = 16.6He = 0.846

A50 = 10.2He = 0.736

A50 = 16.6He = 0.846

A50 = 10.2He = 0.736

A50 = 16.6He = 0.846

A50 = 10.2He = 0.736

A50 = 16.6He = 0.846

A50 = 10.2He = 0.736

A50 = 16.6He = 0.846

A50 = 10.2He = 0.736

A50 = 16.6He = 0.846

A50 = 10.2He = 0.736

A50 = 16.6He = 0.846

A50 = 10.2He = 0.736

A50 = 16.6He = 0.846

A50 = 10.2He = 0.736

A50 = 16.6He = 0.846

A50 = 10.2He = 0.736

A50 = 16.6He = 0.846

A50 = 10.2He = 0.736

A50 = 16.6He = 0.846

A50 = 10.2He = 0.736

A50 = 16.6He = 0.846

Pinsky et al. Molecular Ecology

% More Alleles in Overfished

●

●

●

●

●

●

●

●

●

●

●

●

Osmeridae

Trachurus

Lutjanus

Serranidae

Sebastes

Gadidae

Scophthalmidae

Clupeidae

Pagrus

Pleuronectidae

Scombridae

Cynoscion

−50 −25 0 25 50

% difference in allelic richness

Drum

Tunas

Flounders

Seabream

Herrings

Turbots

Cods

Rockfishes

Groupers

Snappers

Jack mackerels

Smelts


●

●

●

●

●

●

●

●

●

●

●

●

Osmeridae

Trachurus

Lutjanus

Serranidae

Sebastes

Gadidae

Scophthalmidae

Clupeidae

Pagrus

Pleuronectidae

Scombridae

Cynoscion

−50 −25 0 25 50

Drum

Tunas

Flounders

Seabream

Herrings

Turbots

Cods

Rockfishes

Groupers

Snappers

Jack mackerels

Smelts




●

●

●

●

●

●

●

●

●

●

●

●

Osmeridae

Trachurus

Lutjanus

Serranidae

Sebastes

Gadidae

Scophthalmidae

Clupeidae

Pagrus

Pleuronectidae

Scombridae

Cynoscion

−50 −25 0 25 50

Drum

Tunas

Flounders

Seabream

Herrings

Turbots

Cods

Rockfishes

Groupers

Snappers

Jack mackerels

Smelts


Overfished populations have higher

diversity

Overfished populations have lower

diversity



●

●

●

●

●

●

●

●

●

●

●

●

Osmeridae

Trachurus

Lutjanus

Serranidae

Sebastes

Gadidae

Scophthalmidae

Clupeidae

Pagrus

Pleuronectidae

Scombridae

Cynoscion

−50 −25 0 25 50

Drum

Tunas

Flounders

Seabream

Herrings

Turbots

Cods

Rockfishes

Groupers

Snappers

Jack mackerels

Smelts




●

●

●

●

●

●

●

●

●

●

●

●

Osmeridae

Trachurus

Lutjanus

Serranidae

Sebastes

Gadidae

Scophthalmidae

Clupeidae

Pagrus

Pleuronectidae

Scombridae

Cynoscion

−50 −25 0 25 50

Drum

Tunas

Flounders

Seabream

Herrings

Turbots

Cods

Rockfishes

Groupers

Snappers

Jack mackerels

Smelts


9 of 12 groups have lower diversity in overfished populations



●

●

●

●

●

●

●

●

●

●

●

●

Osmeridae

Trachurus

Lutjanus

Serranidae

Sebastes

Gadidae

Scophthalmidae

Clupeidae

Pagrus

Pleuronectidae

Scombridae

Cynoscion

−50 −25 0 25 50

Drum

Tunas

Flounders

Seabream

Herrings

Turbots

Cods

Rockfishes

Groupers

Snappers

Jack mackerels

Smelts


Average: 12% lower


Findings

• Weak bottleneck now

Findings

• Weak bottleneck now •  Impacts likely started ~1950s: rapid!

Findings

• Weak bottleneck now •  Impacts likely started ~1950s: rapid! • Becoming stronger with time

Findings

• Weak bottleneck now •  Impacts likely started ~1950s: rapid! • Becoming stronger with time • Lower ability to adapt in the future

Summary

• Genetic diversity provides the raw material for evolution

Summary


• Evolution is happening all around us

Summary


• Evolution is happening all around us • Humans can influence the course of

evolution