10.5061/DRYAD.DV41NS1WG
Gibson, Amanda
0000-0002-0867-4953
University of Virginia
Nguyen, Anna
University of Virginia
Does genetic diversity protect host populations from parasites? A
meta-analysis across natural and agricultural systems
Dryad
dataset
2020
host-parasite interactions
Coevolution
FOS: Natural sciences
2020-11-12T00:00:00Z
2020-11-12T00:00:00Z
en
https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42018110991.
1834140 bytes
3
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
If parasites transmit more readily between closely related hosts, then
parasite burdens should decrease with increased genetic diversity of host
populations. This important hypothesis is often accepted at face value -
notorious epidemics of crop monocultures testify to the vulnerability of
host populations that have been purged of diversity. Yet the relationship
between genetic diversity and parasitism likely varies across contexts,
differing between crop and non-crop hosts and between experimental and
natural host populations. Here, we used a meta-analytic approach to ask if
host diversity confers protection against parasites over the range of
contexts in which it has been tested. We synthesized the results of 102
studies, comprising 2,004 effect sizes representing a diversity of
approaches and host-parasite systems. Our results validate a protective
effect of genetic diversity, while revealing significant variation in its
strength across biological and empirical contexts. In experimental host
populations, genetic diversity reduces parasitism by ~20% for non-crop
hosts and by ~50% for crop hosts. In contrast, observational studies of
natural host populations show no consistent relationship between genetic
diversity and parasitism, with both strong negative and positive
correlations reported. This result supports the idea that, if parasites
preferentially attack close relatives, the correlation of genetic
diversity with parasitism could be positive or negative depending upon the
potential for host populations to evolve in response to parasite
selection. Taken together, these results reinforce genetic diversity as a
priority for both conservation and agriculture and emphasize the
challenges inherent to drawing comparisons between controlled experimental
populations and dynamic natural populations.