Howard H. Whiteman, Ph.D. is our #RacerScholar this week!

whitemanProfessor Whiteman is our featured #RacerScholar this week. He co-authored the article, “Are Commonly Used Fitness Predictors Accurate? A Meta-analysis of Amphibian Size and Age at Metamorphosis,” which appeared in the July 2015 issue of Copeia.

This volume of Copeia is an Open Access Journal, which provides full access to readers (See Figure 1.)

Abstract

Reaching developmental milestones younger and at larger sizes is commonly claimed to reflect increased fitness. However, the amount of fitness gained from being larger and younger at a milestone may vary with several attributes, particularly evolutionary history, life history, and environmental characteristics. We used a meta-analysis to investigate whether these attributes affected the utility of developmental milestones to be used as predictors of future fitness. We chose amphibian size at and time to metamorphosis (SAM and TTM, respectively) as model developmental milestones, because studies have examined SAM and TTM’s efficacy for fitness prediction (via post-metamorphic fitness proxies), and they are commonly used in a variety of studies testing ecological and evolutionary theory and more applied research on the effects of anthropogenic stressors. We found variation in the predictive power of SAM and TTM for post-metamorphic performance. SAM was a more consistent predictor of post-metamorphic performance than TTM, but also had a higher sample size. Life history and study design (i.e., laboratory vs. field studies), but not evolutionary history, were important for explaining variation in predictive power for post-metamorphic performance. The correlation between SAM and performance increased with the proportion of time to maturity reached at metamorphosis, suggesting that species can compensate for initial fitness reductions through ontogeny. Because numerous researchers use size and age at developmental milestones to indicate fitness, we urge caution in interpreting their results due to the species- and system-specific nature of fitness surrogates.

Figure1Copeia

00458511-103-2-coverAre Commonly Used Fitness Predictors Accurate?
A Meta-analysis of Amphibian Size and
Age at Metamorphosis

By: Julia E. Earl and Howard H. Whiteman
Copeia: July 2015, vol. 103 (2), pgs. 297-309
DOI: 10.1643/CH-14-128

 

Our #Racer Scholars this week are: Dr. Michael B. Flinn, Dr. James Hereford, Nissa Wilson, and Brian West

Our #RacerScholars this week are Nissa Wilson, Dr. Michael B. Flinn, Brian West and Dr. James Hereford. The students and professors are from the Department of Biological Sciences and the Institute of Engineering at Murray State University. Their article, “Identification of Sound-Producing Hydrophilid Beetles (Coleoptera: Hydrophilidae) in Underwater Recordings Using Digital Signal Processing,” appears in the June 2015 issue of Coleopterists Bulletin

Abstract

Hydrophone recordings from three aquatic beetle species within the family Hydrophilidae, Berosus pantherinus (LeConte), Tropisternus blatchleyi (d’Orchymont), and Tropisternus collaris (F.), were used to create an automated identification program. The identification program was designed using digital signal processing techniques and is capable of identifying which species is present from hydrophone recordings alone. Using features based on the frequency content of each beetle call and background sounds in reference recordings, half-second segments of audio recordings were classified as a specific beetle species call, a general beetle distress call, or as noise. Classification accuracy ranged from 87.5% for reference recordings. Training calls had accuracies of 98% and above between beetle species and noise. The majority of beetle recordings in a mesocosm environment were classified correctly. Often, T. blatchleyi was false-positively identified in recordings with non-beetle background noises, such as frogs or traffic, suggesting similar active frequencies in the T. blatchelyi features and these noises. The use of digital signal processing to identify aquatic invertebrates by sound is a new technique that has potential uses in taxonomy, surveys, and long-term biomonitoring of aquatic systems by providing a hands-free method of detection, and eventually identification, in the field.

Identification of Sound-Producing Hydrophilid Beetles (Coleoptera: Hydrophilidae) in Underwater Recordings
Using Digital Signal Processing
By: Nissa Wilson, Michael B. Flinn, Brian West
and James Hereford
Coleopterists Bulletin
, June 2015, vol. 69 (2), pgs. 305-315
doi: 10.1649/0010-065X-69.2.305