Population Biology of Fin Whales: Applying Demographic and Evolutionary Approaches to Studying Populations

Abstract

Acknowledgements 6'population' is used for all these concepts, so it is not amazing that confusion has arisen. This confusion is the more dangerous, since 'population' (in the meaning of local breeding population) plays an important part in the theory of (micro-) evolution.Jonckers (1973) 2005). Tulloch et al. (2019) aimed to quantify the effect of climate change on the recovery of baleen whale populations. Their ecosystem-modelling approach accounted for predatorprey interactions, projected changed in sea surface temperature, changing prey availability, changing distribution of whales, shifts in migration patterns, and inter-specific competition. Baleen whale populations in the Southern Hemisphere were predicted to decline in response to reduced prey availability from increased sea surface temperature and increasing interspecific competition (Tulloch et al., 2019). The study serves as an example of the complex dynamics between predator and prey populations and their physical environment. Statistical models may not succeed in the exact representation of natural systems, but they can offer useful approximations of the real world or in the words of George Box ( 1979) "all models are wrong but some are useful". Conservation biologyConservation biology integrates conservation policy with theories developed in population ecology and evolutionary biology to mitigate anthropogenic impacts on biological diversity and to prevent the extinction of species (Soulé, 1985). Populations are the primary target of management and policy directives that aim to provide effective protection to small or declining populations (Shaffer, 1981). In this context, the terms 'management unit' or 'stock' are frequently used to refer to "geographical areas with restricted interchange of the individuals of interest with adjacent areas" (Taylor & Dizon, 1999). How this definition translates to delineating management units in natural populations is a matter of debate (Palsbøll et al., 2007;Taylor & Dizon, 1999). While population genetics provide a means of quantifying population differentiation, the decision on the threshold level of interchange, in this case gene flow, mainly depends on the demographic context and management objectives (Palsbøll et al., 2007;Taylor & Dizon, 1999). A statistical test on whether the null hypothesis of panmixia can be rejected at an arbitrary level is rarely sufficient to delineate meaningful management units (Palsbøll et al., 2007;Taylor & Dizon, 1999). Weakly structured populations or those following a stepping-stone model pose a particular challenge as to where to draw the line (Spies et al., 2015).Once a management unit has been defined, population viability analysis (PVA) can be employed to estimate the likelihood of reaching a threshold level, e.g. extinction, under current or managed conditions (Boyce, 1992). PVAs are generally quantitative model-based assessments of extinction/persistence that can incorporate elements of spatially-explicit and/or individual-based models, sensitivity analysis, or genetic ef...