Evolution of Mating Systems

Who and how many males a female mates with has important implications for sexual selection, maintenance of genetic and phenotypic variability of offspring, and post-copulatory conflict that all drive evolutionary processes. Despite having hypotheses for the evolution of multiple mating, multiple hypotheses have rarely been evaluated in wild populations, within a single species, and evaluated with manipulative lab experiments informed by data from the field. Therefore, through manipulative mating designs and parentage analysis using microsatellite markers I 1) characterize patterns of polyandry in the field; 2) investigate how the number of mates affect phenotypic and genetic diversity of offspring; 3) characterize paternity skewness and potential causes of sire dominance.

Publications: Coming soon(ish)!

Phenotypic Plasticity

Genotypes within many species have the ability to produce a variety of phenotypes in response to different environments. Plastic responses can be elicited by predators, also known as inducible defenses. When species have low-dispersal and low migration between populations, these populations may evolve different phenotypic responses to the same environment. This was evident in three populations of the the marine gastropod, Littorina saxatilis, which all had the same shell shape response to their native crab predator (Dyspanopeus sayi) but had different shape responses to a newly introduced predator (Hemigrapsus sanguineus). As H. sanguineus (the Asian shore crab) has been co-existing with these populations of snails for ~8-20 generations, it is possible that we captured a transitional period of predator recognition for these populations

Hooks, A.P. and Padilla, D.K.  2020. Introduced Predator Elicits Population-Specific Responses from Prey. Biol. Invasions. 7: 1-14. https://doi.org/10.1007/s10530-020-02376-5

Hooks, A.P. and Padilla, D.K.  2014.  Prey responses to the presence of a native and nonnative predator.  J. Exp. Mar. Biol. Ecol. 461: 209-215. https://doi.org/10.1016/j.jembe.2014.07.022

Larval Biology

Larval development is usually classified into discrete modes such as feeding or non-feeding larvae, swimming or non-swimming larvae, or benthic versus pelagic development. These developmental modes are often used to predict dispersal potential. However, these classifications can hide variation in marine larvae. In a recent project, we quantified the swimming behavior of a crawl-away larvae of the Florida crown conch (Melongena corona). These larvae crawl-away from benthic egg capsules but have a fully-formed velum in which they can swim. This switching behavior of crawling and swimming and back again can occur for over 12 days after emergence. In a recent study, we quantified swimming of hatchlings in different environmental cues to determine the function of this velum and then test metamorphic competency of individuals at different ages. Our major findings are: 1) hatchlings swim in all conditions, but swim more with no cues; 2) they grow with juvenile food present (live sand) but have very little growth with larval food present (phytoplankton); and 3) individuals maintained in both the lab and field conditions had the ability to metamorphose days before they did.

Ecological Genetics

An impact of invasive species can include the hybridization between native and invasive populations. During my undergraduate, I worked in Dr. Jerry Hilbish’s lab where I examined the hybrid zone between the native blue mussel, Mytilus trossulus, and the invasive blue mussel, Mytilus galloprovincialis.

Also during my undergraduate, I completed an independent project in Dr. Joseph Quattro’s lab investigating the genetic differentiation of an imperiled catfish the “broadtail” madtom (Noturus genus) from other species in the same genus.