Conservation Genetics of Tropical Vertebrates
Chaired by:
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Sofia Solórzano, FES Iztacala, Universidad Nacional Autónoma de México,
Mexico
Omar Chassin, Facultad de Biología-CMEB, UMSNH, Mexico
Philip Hedrick, Arizona State University
One of the main goals of Conservation Genetics is to analyze the genetic risks that may
cause the extinction of taxa. In tropical regions, large animals, endemic taxa, and small
isolated vertebrate populations represent a priority for Conservation Biology since their
populations have been severely impacted by habitat destruction. The effects of habitat
destruction are different for many vertebrate groups such as Reptiles, Fish, Birds, and
Mammals because they all possess different conservation strategies. The main goal of
this symposium is to present the theoretical basis, the current status, and future
perspectives of Conservation Genetics in tropical regions, as well as their applications to
the conservation of tropical vertebrates. We include case studies that show both the
methodological strategies and the main findings to accomplish the conservation of
threatened animal species from different tropical regions. This symposium is sponsored
by Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (FU004), Mexico,
and CIEco, UNAM, Mexico.
Genomics and the conservation of species
Stephen J. O’Brien.
Laboratory of Genomic Diversity. National Cancer Institute. Frederick, Maryland, USA.
Advances in population and quantitative genomics, aided by the computational
algorithms that employ genetic theory and practice, are now being applied to biological
questions that surround free-ranging species not traditionally suitable for genetic enquiry.
My presentation will highlight applications of molecular genetic tools have been used to
describe the natural history, present status, and future disposition of wild species of
mammals. Insight into phylogenetic hierarchy, demographic contractions, geographic
population substructure, behavioral ecology and infectious diseases have revealed
strategies for survival and adaptation of many fascinating mammalian species. I will
discuss the resolution of the earliest divergences of placental mammal forbearers, the
phylogenetic hierarchy of the Felidae radiation, discovery of new species of mammals
and examples of recent migration events in ancestral taxa revealed by genomic
prospecting in modern big cat species.
Genetic diversity and molecular relationships among members of the
genus chirostoma (Atherinopsidae: Menidiinae)
Irene de los Angeles Barriga-Sosa1, Claudia Gárnica-Rivera1, Mónica Y. PérezRamírez1, José Luis Arredondo-Figueroa1, Rodrigo Moncayo–Estrada and
Francisco J. García de León2
1
Planta Experimental de Producción Acuícola, Departamento de Hidrobiología, División
de CBS, Universidad Autónoma Metropolitana-Iztapalapa, Mexico.
2
Centro de Investigaciones Biológicas del Noroeste, Mexico.
Email: ibs@xanum.uam.mx
The atherinopsids of the Central Mexico are a group of endemic fish species that have
been for centuries an important natural resource for ethnic populations from lakes
Patzcuaro, Chapala, Cuitzeo and Zirahuen. Presently, the effects of over-explotation,
eutrophication and contamination are driving towards the loss of this biodiversity. Here
are presented information regarding levels of genetic variation, and relations among
Chirostoma species based on partial sequences of three mitochondrial DNA regions
(control region (CR), 300 pb; cytochrome b (Cytb), 400 pb and r16S, 375 pb). The levels
of genetic diversity () ranged from 0.00000 to 0.04282 for these three regions. As
expected the levels of resolution were: CR resolved variation at the intra-specific level,
cytb at the intra and inter-specific level and r16S showed the lowest levels of variation.
CR and cytb showed overall sequence variation (N = 91) that resulted in 24 and 17
haplotypes, respectively and intermediate levels of nucleotide diversity ( = 0.04282 ±
0.00469; 0.0256 ± 0.00297, respectively). Chirosotma jordani showed the highest levels
(0.03926 ± 0.01735), followed by C. humboldtianum and C. estor , (0.03393± 0.00162
and 0.01971 ± 0.00175, respectively), C. labarcae and the Poblana spp., had only one
haplotype each and cero levels of diversity. The sequences of the r16S (N = 87, 375 pb)
showed overall lower levels of diversity (0.01850±0.00291), with C. jordani showing the
highest levels (0.01655±0.00668), followed by C. humboldtianum (0.00571±0.00044)
and C. estor (0.00019±0.00017) and C. labarcae and Poblana spp., showing only one
haplotype each. The levels of genetic diversity and divergence between the species
analyzed supported the genetic identity of the Chirostoma species, however a close
monitoring should be carry out in C. labarcae and Poblana those species that showed the
lowest levels of genetic variation in order to suggest further proceedings.
Keywords: Chirostoma, Poblana, Control Region, cytochrome b, r16S
Systematics and conservation genetics of the Chelonia genus: two
approaches to one issue
Omar Chassin-Noria1 and Ken Oyama2
1
Facultad de Biologia-CMEB, UMSNH
2
Centro de Investigaciones en Ecosistemas, Universidad Nacional Autónoma de México
Email: chassin@oikos.unam.mx
There is a taxonomic controversy on the Chelonia genus, some authors argue that this is a
monospecific genus and others argue that there are two different species (C. mydas and
C. agassizii). Here we review this issue and its impact for conservation purposes based on
a molecular approach. Then we show a genetic analysis of the main continental nesting
rookery of the east Pacific population that has suffered drastic population declines
following intense exploitation in the 1960s-1970s. Analyses of three nDNA microsatellite
loci and 400 bp mtDNA control region sequences from a total of 123 nesting females
sampled at Michoacan state (Mexico) show no evidence of population sub-structuring
and no apparent impact of population reduction on genetic diversity in either control
region sequences (overall h = 0.48; = 0.0036) or microsatellite loci (overall Na = 20.8;
Hexp = 0.895). Our estimates of annual effective female population size (Nef; from ) of
1.9-2.3 x 103, in spite of being an order of magnitude below historical records, appear to
be sufficient to allow recovery of this population without significant loss of genetic
diversity. These findings highlight the importance of continued conservation activities to
reverse the decline of this population, even there are no support for its taxonomic
differentiation.
Keywords: Chelonia, Systematics, Conservation genetics
Establishing a general conservation strategy for threatened taxa based
on ecologic and genetic data: the case of the Mesoamerican Resplendent
Quetzal (Aves: Pharomachrus mocinno)
Sofia Solórzano1 and Ken Oyama2
1
FES Iztacala, Universidad Nacional Autónoma de México
2
Centro de Investigaciones en Ecosistemas, Universidad Nacional Autónoma de México
Email: solorzanols@campus.iztacala.unam.mx
Mesoamerica is a world hotspot area since it contains a high biodiversity. In this region
are about 5% of threatened endemic vertebrates represented by small isolated remnant
populations. Most of these taxa still remain without basic information that allows
establishing conservation and management plans to long term. In the present study we
propose a general strategy to establish conservation programs following available
ecologic and genetic data. In this study we used the case of Resplendent Quetzal
(Pharomachrus mocinno) a bird species worldwide listed into Lower Risk near
Threatened but in each of the seven countries that it occupies is considered as endangered
specie. This endemic Mesoamerican bird ranges from southern Mexico to northwest
Panama showing an isolated distribution pattern. Recent studies showed that the 70% of
the quetzal habitats were destroyed and consequently causing local extinctions at
southern Mexico. Additionally, genetic analysis based on mtDNA sequences and
morphological data showed strong partition within P. mocinno. Integrating all these data
we propose that a strategy to establish conservation programs for quetzals and other
vertebrate of similar status. 1) to evaluate quantitatively the potential threats, 2) to
identify geographic areas that would be preserved to long term and, 3) to maintain the
connectivity among such areas design a system of natural protected areas and biological
corridors; 4) to overlap genetic analysis onto the geographical areas chose according with
genetic identity, instead a detailed population genetic structure that is hard to accomplish
considering the rarity and the small population sizes of endemic threatened taxa. Based
on this strategy we found that in Mesoamerica there are about 12 highest priority areas
that should be conserved to maintain to long term Resplendent Quetzal populations.
These areas need international agrees to guarantee that the connectivity among them.
Keywords: Mesoamerica, Pharomachrus mocinno, Conservation priority areas
Conservation genetics of Mexican Wolves
Phil Hedrick and Fredrickson Rich
Arizona State University
Email: philip.hedrick@asu.edu
The Mexican wolf (Canis lupus baileyi) was hunted to near extinction in the middle of
the last century. A captive breeding program for the Mexican wolf was established in the
late 1970s from three founders (two other lineages, with two founders each were
subsequently added). A reintroduced population of about 50 animals, descended from this
captive population, exists in Arizona and New Mexico today. There is evidence of
genetic rescue as the result of merging these three lineages in both the captive and
reintroduced population. The captive populations of Mexican wolves has been closely
managed to minimize mean kinship and there has also been an extensive effort to monitor
wolves in the reintroduced population and determine their pedigree relationships. In
addition, there have been efforts to augment and change the constitution of the wild
population by releases from captivity. These management actions, the current status of
the captive and reintroduced population, and potential recommended further management
alternatives will be evaluated and discussed.
Keywords: genetics, Mexican wolves, inbreeding, genetic rescue
Perspectives of conservation genetics in tropical regions
Stephen J. O’Brien1,
4
Arizona State University
No abstract available.
Discussion and final remarks: The creation of a conservation genetics
network for tropical regions.
Sofia Solórzano1, Omar Chassin2, and Philip Hedrick3
1
FES Iztacala, Universidad Nacional Autónoma de México, México
2
Facultad de Biología-CMEB, UMSNH, Mexico
3
Laboratory of Genomic Diversity, National Cancer Institute, Frederick, Maryland, USA
The objective of this final discussion is to identify a general strategy of conservation that
is applicable for most tropical animal species, based on theory, experience and empirical
data presented by the symposium speakers as general public. We will present a strategy
for the creation of a Conservation Genetic network for tropical regions, and particularly
for Latin America and Mexico.