Town population size and structuring into villages and households drive infectious disease risks in pre-healthcare Finland

Tarmo Ketola, Michael Briga, Terhi Honkola and Virpi Lummaa 2021: Proc R Soc B
DOI: 10.1098/rspb.2021.0356

ABSTRACT

Social life is often considered to cost in terms of increased parasite or pathogen risk. However, evidence for this in the wild remains equivocal, possibly because populations and social groups are often structured, which affects the local transmission and extinction of diseases. We test how the structuring of towns into villages and households influenced the risk of dying from three easily diagnosable infectious diseases—smallpox, pertussis and measles— using a novel dataset covering almost all of Finland in the pre-healthcare era (1800–1850). Consistent with previous results, the risk of dying from all three diseases increased with the local population size. However, the division of towns into a larger number of villages decreased the risk of dying from smallpox and to some extent of pertussis but it slightly increased the risk for measles. Dividing towns into a larger number of households increased the length of the epidemic for all three diseases and led to the expected slower spread of the infection. However, this could be seen only when local population sizes were small. Our results indicate that the effect
of population structure on epidemics, disease or parasite risk varies between pathogens and population sizes, hence lowering the ability to generalize the consequences of epidemics in spatially structured populations, and mapping the costs of social life, via parasites and diseases.

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Virpi was given the inaugural Phoenix Award from the Turku Finnish University Society on Friday in recognition of and encouragement for her consistently creative and internationally high-quality re

We had the pleasure of hosting Silke van Daalen from the University of Amsterdam for three weeks this September. Silke is a PhD student working with Hal Caswell on identifying individual stochasticity in life-history traits of long-lived populations with a mathematical modelling approach, and came to learn about our dataset and how she might be able to use it in her work. We wish her the best of luck with the rest of her PhD studies, and hope to see her again soon!

Another year, another project meeting! This time we stayed on the beautiful island of Seili, again with the lovely people from the Myanmar Timber Elephant Project, for a few days of talks, drinks, and sauna. Needless to say, there is plenty of interesting and exciting work underway - keep your eyes peeled for the results, coming soon (hopefully) to peer-reviewed journals near you!
 

John Loehr with his workgroup received EUR 225.000 grant from Kone Foundation in 2016 for their project Learning from the past: the effect of forced migration from Karelia on family life.
Karelia-project had their kick-off meeting at the University of Turku 19.4.2017. Intense discussions, good spirit and a lot of inspiration among the team!

Menikö luonnonvalinnalla jotain pieleen: Miksi nainen elää menopaussin jälkeen lähes saman mokoman vaikkei voi saada jälkeläisiä?

Virpi Lummaa

Our multidisciplinary research team is looking for a post-doctoral researcher for a three-year project investigating life history, social integration and the influence of kin in forced migrants in a 20th century Finnish population.

The project is an exciting opportunity to investigate the consequences of forced migration of over 400000 people during World War II from an evolutionary ecology and sociology viewpoint. These migrants encountered much the same traumas and faced similar prejudices and resentment that current migrants face today, making the study of this population particularly appropriate to gain insight into the present and future of current migrants.
 

John Loehr with his workgroup received EUR 225.000 grant from Kone Foundation in 2016 for their project Learning from the past: the effect of forced migration from Karelia on family life.

The plight of migrants has come to the forefront recently as masses of people have migrated to Europe seeking asylum from predicaments faced at home. Many people in Finland seem to have forgotten that over 400,000 Finnish people had to abandon their homes in Karelia as a result of World War II. In this cross-disciplinary project, directed by John Loehr, an ecological scientist, biologists, sociologists, historians and demographic researchers study how enforced migration has affected family relations, having children, and integration into the community.

Kimmo Pokkinen is a man behind the Finnish church book data which he has been collecting for years. He had a big day recently and there was a fair reason to serve some birthday cake for him at the university. Congratulations!

Carly, Verane, Simon, Kimmo, Virpi, Jenni, Samuli, Martin, Mirkka

The research group spent three intense days having a brilliant Project Meeting in Tampere, Finland in August 2016. The venue was the most beautiful place by the lake, surrounded by the pristine Finnish nature. A perfect venue for the best conference ever! Special thanks to our hosts Jenni and Esko.
Photos from the Project Meeting in Kesämaa, Finland, August 2016. Photos by Esko Pettay / Wild TechPhotos Oy.

Virpi Lummaa's Group: Project meeting in Finland, August 2016. Photo by Esko Pettay

Virpi Lummaa is an outstanding evolutionary biologist and her work has led to significant advances in our understanding of the ecological causes and evolutionary consequences of variation in reproductive success and longevity. Her research on humans, based on detailed pedigrees, and birth and death records, revealed the selection pressures shaping life history in pre-industrial populations, and in so doing allowed for the first rigorous, scientific examination of human behavioural ecology. These findings have revealed the complex trade-offs shaping recent human evolution.
The Scientific Medal, Britain's zoological Oscar, is awarded to scientists with up to 15 years postdoctoral experience for distinguished work in zoology.

Virpi Lummaa Scientific Medal 2016 Zoological Society of London