Spheniscidae (1 Viewer)

[Peter Kovalik]

Cole, T.L., C. Zhou, M. Fang, H. Pan, D.T. Ksepka, S.R. Fiddaman, C.A. Emerling, D.B. Thomas, X. Bi, Q. Fang, M.R. Ellegaard, S. Feng, A.L. Smith, T.A. Heath, A.J.D. Tennyson, P. García Borboroglu, J.R. Wood, P.W. Hadden, S. Grosser, C.-A. Bost, Y. Cherel, T. Mattern, T. Hart, M.-H.S. Sinding, L.D. Shepherd, R.A. Phillips, P. Quillfeldt, J.F. Masello, J.L. Bouzat, P.G. Ryan, D.R. Thompson, U. Ellenberg, P. Dann, G. Miller, P.D. Boersma, R. Zhao, M.T.P. Gilbert, H. Yang, D.-X. Zhang, and G. Zhang. 2022. Genomic insights into the secondary aquatic transition of penguins. Nature Communications 13: 3912. published 19 July 2022. Genomic insights into the secondary aquatic transition of penguins - Nature Communications

Abstract
Penguins lost the ability to fly more than 60 million years ago, subsequently evolving a hyper-specialized marine body plan. Within the framework of a genome-scale, fossil-inclusive phylogeny, we identify key geological events that shaped penguin diversification and genomic signatures consistent with widespread refugia/recolonization during major climate oscillations. We further identify a suite of genes potentially underpinning adaptations related to thermoregulation, oxygenation, diving, vision, diet, immunity and body size, which might have facilitated their remarkable secondary transition to an aquatic ecology. Our analyses indicate that penguins and their sister group (Procellariiformes) have the lowest evolutionary rates yet detected in birds. Together, these findings help improve our understanding of how penguins have transitioned to the marine environment, successfully colonizing some of the most extreme environments on Earth.

 

[Melanie]

Designation of a neotype for Eudyptula minor (Aves: Spheniscidae)​

No abstract

Designation of a neotype for Eudyptula minor (Aves: Spheniscidae) | Zootaxa

mapress.com

 

[albertonykus]

Herman, R.W., G. Clucas, J. Younger, J. Bates, B. Robinson, S. Reddy, J. Stepanuk, K. O'Brien, K. Veeramah, and H.J. Lynch (2024)
Whole genome sequencing reveals stepping-stone dispersal buffered against founder effects in a range expanding seabird
Molecular Ecology (advance online publication)
doi: 10.1111/mec.17282

Many species are shifting their ranges in response to climate-driven environmental changes, particularly in high-latitude regions. However, the patterns of dispersal and colonization during range shifting events are not always clear. Understanding how populations are connected through space and time can reveal how species navigate a changing environment. Here, we present a fine-scale population genomics study of gentoo penguins (Pygoscelis papua), a presumed site-faithful colonial nesting species that has increased in population size and expanded its range south along the Western Antarctic Peninsula. Using whole genome sequencing, we analysed 129 gentoo penguin individuals across 12 colonies located at or near the southern range edge. Through a detailed examination of fine-scale population structure, admixture, and population divergence, we inferred that gentoo penguins historically dispersed rapidly in a stepping-stone pattern from the South Shetland Islands leading to the colonization of Anvers Island, and then the adjacent mainland Western Antarctica Peninsula. Recent southward expansion along the Western Antarctic Peninsula also followed a stepping-stone dispersal pattern coupled with limited post-divergence gene flow from colonies on Anvers Island. Genetic diversity appeared to be maintained across colonies during the historical dispersal process, and range-edge populations are still growing. This suggests large numbers of migrants may provide a buffer against founder effects at the beginning of colonization events to maintain genetic diversity similar to that of the source populations before migration ceases post-divergence. These results coupled with a continued increase in effective population size since approximately 500–800 years ago distinguish gentoo penguins as a robust species that is highly adaptable and resilient to changing climate.

 

[albertonykus]

McComish, B.J., M.A. Charleston, M. Parks, C. Baroni, M.C. Salvatore, R. Li, G. Zhang, C.D. Millar, B.R. Holland, and D.M. Lambert (2024)
Ancient and modern genomes reveal microsatellites maintain a dynamic equilibrium through deep time
Genome Biology and Evolution 16: evae017
doi: 10.1093/gbe/evae017

Microsatellites are widely used in population genetics, but their evolutionary dynamics remain poorly understood. It is unclear whether microsatellite loci drift in length over time. This is important because the mutation processes that underlie these important genetic markers are central to the evolutionary models that employ microsatellites. We identify more than 27 million microsatellites using a novel and unique dataset of modern and ancient Adélie penguin genomes along with data from 63 published chordate genomes. We investigate microsatellite evolutionary dynamics over 2 timescales: one based on Adélie penguin samples dating to ∼46.5 ka and the other dating to the diversification of chordates aged more than 500 Ma. We show that the process of microsatellite allele length evolution is at dynamic equilibrium; while there is length polymorphism among individuals, the length distribution for a given locus remains stable. Many microsatellites persist over very long timescales, particularly in exons and regulatory sequences. These often retain length variability, suggesting that they may play a role in maintaining phenotypic variation within populations.