- Ivory poaching and the rapid evolution of tusklessness in African
elephantsShane C. Campbell-Staton, Brian J. Arnold, Dominique Gonçalves,
Petter Granli, Joyce Poole, Ryan A. Long, and Robert M.
PringleScienceOctober 22, 2021Lose the tusks*
Harvest and poaching of wildlife have increased as the human population and
our technology have grown. These pressures now occur on such a scale that
they can be considered selective drivers. Campbell-Staton et al. show that
this phenomenon has occurred in African elephants, which are poached for
their ivory, during the 20-year Mozambican civil war (see the Perspective
by Darimont and Pelletier). In response to heavy poaching by armed forces,
African elephant populations in Gorongosa National Park declined by 90%. As
the population recovered after the war, a relatively large proportion of
females were born tuskless. Further exploration revealed this trait to be
sex linked and related to specific genes that generated a tuskless
phenotype more likely to survive in the face of poaching. —SNV
Abstract
Understanding the evolutionary consequences of wildlife exploitation is
increasingly important as harvesting becomes more efficient. We examined
the impacts of ivory poaching during the Mozambican Civil War (1977 to
1992) on the evolution of African savanna elephants (Loxodonta africana) in
Gorongosa National Park. Poaching resulted in strong selection that favored
tusklessness amid a rapid population decline. Survey data revealed
tusk-inheritance patterns consistent with an X chromosome–linked dominant,
male-lethal trait. Whole-genome scans implicated two candidate genes with
known roles in mammalian tooth development (AMELX and MEP1a), including the
formation of enamel, dentin, cementum, and the periodontium. One of these
loci (AMELX) is associated with an X-linked dominant, male-lethal syndrome
in humans that diminishes the growth of maxillary lateral incisors
(homologous to elephant tusks). This study provides evidence for rapid,
poaching-mediated selection for the loss of a prominent anatomical trait in
a keystone species.
FULL PAPER PDF
LINKhttps://drive.google.com/file/d/1ZI96hPQn1xdGM1Hma7g1FEMyP01sro87/view?usp=sharing
https://drive.google.com/file/d/1ZI96hPQn1xdGM1Hma7g1FEMyP01sro87/view?usp=sharingFULL
PAPER WEB LINKhttps://www.science.org/doi/10.1126/science.abe7389
https://www.science.org/doi/10.1126/science.abe7389
* Ivory poaching and the rapid evolution of tusklessness in African
elephantsShane C. Campbell-Staton, Brian J. Arnold, Dominique Gonçalves,
Petter Granli, Joyce Poole, Ryan A. Long, and Robert M.
PringleScienceOctober 22, 2021Lose the tusks*
Harvest and poaching of wildlife have increased as the human population and
our technology have grown. These pressures now occur on such a scale that
they can be considered selective drivers. Campbell-Staton et al. show that
this phenomenon has occurred in African elephants, which are poached for
their ivory, during the 20-year Mozambican civil war (see the Perspective
by Darimont and Pelletier). In response to heavy poaching by armed forces,
African elephant populations in Gorongosa National Park declined by 90%. As
the population recovered after the war, a relatively large proportion of
females were born tuskless. Further exploration revealed this trait to be
sex linked and related to specific genes that generated a tuskless
phenotype more likely to survive in the face of poaching. —SNV
*Abstract*
Understanding the evolutionary consequences of wildlife exploitation is
increasingly important as harvesting becomes more efficient. We examined
the impacts of ivory poaching during the Mozambican Civil War (1977 to
1992) on the evolution of African savanna elephants (Loxodonta africana) in
Gorongosa National Park. Poaching resulted in strong selection that favored
tusklessness amid a rapid population decline. Survey data revealed
tusk-inheritance patterns consistent with an X chromosome–linked dominant,
male-lethal trait. Whole-genome scans implicated two candidate genes with
known roles in mammalian tooth development (AMELX and MEP1a), including the
formation of enamel, dentin, cementum, and the periodontium. One of these
loci (AMELX) is associated with an X-linked dominant, male-lethal syndrome
in humans that diminishes the growth of maxillary lateral incisors
(homologous to elephant tusks). This study provides evidence for rapid,
poaching-mediated selection for the loss of a prominent anatomical trait in
a keystone species.
*FULL PAPER PDF
LINKhttps://drive.google.com/file/d/1ZI96hPQn1xdGM1Hma7g1FEMyP01sro87/view?usp=sharing
<https://drive.google.com/file/d/1ZI96hPQn1xdGM1Hma7g1FEMyP01sro87/view?usp=sharing>FULL
PAPER WEB LINKhttps://www.science.org/doi/10.1126/science.abe7389
<https://www.science.org/doi/10.1126/science.abe7389>*