Simulating genomic effects of habitat loss and population bottlenecks with spatially explicit models
(2022) BIOM02 20211Degree Projects in Biology
- Abstract
- Butterfly wing coloration and pattern are believed to be shaped by selection pressures arising from the needs of thermoregulation, as signals to conspecifics, or reducing predation risk. The Common Blue Butterfly (Polyommatus icarus) display a large variation in dorsal wing blueness among females. The gradual pattern of brown to blue wings varies between individual females and among populations in Sweden. The aims of this study were to investigate the structural basis of blue wing coloration, to obtain a detailed understanding of geographic variation, and to identify potential drivers and mechanisms behind this variation. The results show that the color variation is partly genetically determined and partly caused by phenotypic plasticity... (More)
- Butterfly wing coloration and pattern are believed to be shaped by selection pressures arising from the needs of thermoregulation, as signals to conspecifics, or reducing predation risk. The Common Blue Butterfly (Polyommatus icarus) display a large variation in dorsal wing blueness among females. The gradual pattern of brown to blue wings varies between individual females and among populations in Sweden. The aims of this study were to investigate the structural basis of blue wing coloration, to obtain a detailed understanding of geographic variation, and to identify potential drivers and mechanisms behind this variation. The results show that the color variation is partly genetically determined and partly caused by phenotypic plasticity in relation to the larval temperature environment. By rearing wild caught female’s offspring in controlled lab environment, I showed that the coloration is heritable. However, cooler conditions induce more blue wing color. Local and regional variation in the amount of blue color may be an adaption to the climate, including temperature and precipitation, but could also reflect direct and indirect responses to other abiotic or biotic factors. Scanning Electron Microscope (SEM) images of the dorsal wings of brown and blue females and males reviled different scale types and nanoarchitectures shaping the coloration. These structures might have different functional consequences in terms of thermoregulation and in handling moisture and precipitation but their adaptive significance in P. icarus is yet to be determined. (Less)
- Popular Abstract
- Modelling endangered species - programming the Pink Pigeon
Everyone has heard of the dodo - maybe the most famous bird to go extinct. But the dodo’s neighbour, the pink pigeon, is not so well known. Found only on the island of Mauritius, this charismatic bird bounced back from the brink of extinction thanks to conservation efforts. However, using new computer modelling techniques, we show that the future still holds risks for the genetic health of the species.
When the first Dutch ships arrived on Mauritius more than 400 years ago, they described the island as a tropical paradise; teaming with fish, fowl, and verdant plant life. Unfortunately those settlers also brought with them rats, cats, and foreign weeds that began to change the... (More) - Modelling endangered species - programming the Pink Pigeon
Everyone has heard of the dodo - maybe the most famous bird to go extinct. But the dodo’s neighbour, the pink pigeon, is not so well known. Found only on the island of Mauritius, this charismatic bird bounced back from the brink of extinction thanks to conservation efforts. However, using new computer modelling techniques, we show that the future still holds risks for the genetic health of the species.
When the first Dutch ships arrived on Mauritius more than 400 years ago, they described the island as a tropical paradise; teaming with fish, fowl, and verdant plant life. Unfortunately those settlers also brought with them rats, cats, and foreign weeds that began to change the make-up of the islands ecosystem. Combined with deforestation for ship building and sugar cane farms, soon there was almost no habitat left for the native birds like the pink pigeon. By the 1960’s there were barely more than a dozen individuals left on the island.
However, in the 1970’s conservation efforts began, and
the Mauritian Wildlife Foundation with the Durrel Wildlife Trust began an intensive management and monitoring programme. Remaining natural forest was turned into the Black River Gorges National Park, where feeding stations were set up, and pests removed. Most importantly, a captive breeding population was established, to ensure there was a secure line of birds that could be re-introduced into the wild. These incredible efforts were so successful that there are now more than 400 breeding birds, and the species is no longer considered critically endangered.
An uncertain future?
Despite all the hard work being done, the pink pigeon is still under threat. Having been reduced to such a small number, the current population suffers from genetic health problems because of inbreeding. All the individuals are closely related to each other, which mean they are more vulnerable to parasites and disease, and often produce infertile eggs. These issues make it uncertain if the pink pigeon can securely expand without constant support.
Predicting the future is hard, but computers can make it easier. We have developed a new type of computer model, which simulates the complete history of habitat loss on the island and projects it into the future. This model is populated by virtual organisms that move and reproduce like pink pigeons, complete with individual genomes. Looking at the data from this model suggests that even though numbers might remain stable, the genetic health of the population could continue to worsen. Hopefully this information can be used in the future to inform the breeding programme and management to secure the future of the pink pigeon.
Master’s Degree Project in Biology 30 credits 2021
Department of Biology, Lund University
Advisor: Bengt Hansson, Cock van Oosterhout, Hernan Morales
Lund Molecular Ecology and Evolution Lab (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9075450
- author
- Pinto, Alessandro
- supervisor
- organization
- course
- BIOM02 20211
- year
- 2022
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 9075450
- date added to LUP
- 2022-02-16 12:13:21
- date last changed
- 2022-02-16 12:13:21
@misc{9075450,
abstract = {{Butterfly wing coloration and pattern are believed to be shaped by selection pressures arising from the needs of thermoregulation, as signals to conspecifics, or reducing predation risk. The Common Blue Butterfly (Polyommatus icarus) display a large variation in dorsal wing blueness among females. The gradual pattern of brown to blue wings varies between individual females and among populations in Sweden. The aims of this study were to investigate the structural basis of blue wing coloration, to obtain a detailed understanding of geographic variation, and to identify potential drivers and mechanisms behind this variation. The results show that the color variation is partly genetically determined and partly caused by phenotypic plasticity in relation to the larval temperature environment. By rearing wild caught female’s offspring in controlled lab environment, I showed that the coloration is heritable. However, cooler conditions induce more blue wing color. Local and regional variation in the amount of blue color may be an adaption to the climate, including temperature and precipitation, but could also reflect direct and indirect responses to other abiotic or biotic factors. Scanning Electron Microscope (SEM) images of the dorsal wings of brown and blue females and males reviled different scale types and nanoarchitectures shaping the coloration. These structures might have different functional consequences in terms of thermoregulation and in handling moisture and precipitation but their adaptive significance in P. icarus is yet to be determined.}},
author = {{Pinto, Alessandro}},
language = {{eng}},
note = {{Student Paper}},
title = {{Simulating genomic effects of habitat loss and population bottlenecks with spatially explicit models}},
year = {{2022}},
}