Natural selection in wild beetle populations
(2024) BION03 20222Degree Projects in Biology
- Abstract
- Natural selection is an important force behind evolution. It is well known that phenotypic variation provides opportunity for evolution, but research into how selection acts on specific traits over time is lacking. In this thesis, I studied how selection acts upon the shape and body size of the beetle Cassida viridis. Across three populations, I measured size (length and area), shape, and lifespan in two generations of beetles. In addition, I experimentally assessed predation likelihood in the three populations. Using these data, I modeled the differences across populations to determine if selection is acting on these traits. I found that there was disruptive selection on length in the first generation and shape in the second generation... (More)
- Natural selection is an important force behind evolution. It is well known that phenotypic variation provides opportunity for evolution, but research into how selection acts on specific traits over time is lacking. In this thesis, I studied how selection acts upon the shape and body size of the beetle Cassida viridis. Across three populations, I measured size (length and area), shape, and lifespan in two generations of beetles. In addition, I experimentally assessed predation likelihood in the three populations. Using these data, I modeled the differences across populations to determine if selection is acting on these traits. I found that there was disruptive selection on length in the first generation and shape in the second generation across all three populations, potentially due to predation, intraspecific competition, and a tendency for negative directional selection on size. There were also significant differences in survival across populations. However, I observed no correlation between predation intensity and survival. My results suggest that survival may be correlated with the timing of diapause, which may help us understand why insects enter diapause at certain times. This study is the first to explore how natural selection shapes the body size of C. viridis among populations and suggests that C. viridis has proven to be a useful study system to answer questions about how selection shapes populations. Future studies would benefit from including measurements of sexual selection and following the same individuals or generations across their lifecycle. (Less)
- Popular Abstract (Swedish)
- Naturlig selektion i vilda skalbaggspopulationer
Naturlig selektion är en nyckelfaktor för evolutionen. Även om vi vet att mängden variation i egenskaper (fenotyper) ger råmaterial för selektion och om den är genetisk påverkar evolutionens hastighet, har vi fortfarande mycket att lära om hur naturlig selektion påverkar specifika egenskaper över tid. I min examensuppsats undersökte jag hur naturlig selektion påverkar formen och storleken hos skalbaggen grön sköldbagge (Cassida viridis).
Jag studerade tre vilda skalbaggspopulationer och mätte skalbaggars storlek (längd och area), form och livslängd över två generationer. Jag genomförde också predations-experiment för att se hur sannolikt det var att skalbaggarna i dessa populationer... (More) - Naturlig selektion i vilda skalbaggspopulationer
Naturlig selektion är en nyckelfaktor för evolutionen. Även om vi vet att mängden variation i egenskaper (fenotyper) ger råmaterial för selektion och om den är genetisk påverkar evolutionens hastighet, har vi fortfarande mycket att lära om hur naturlig selektion påverkar specifika egenskaper över tid. I min examensuppsats undersökte jag hur naturlig selektion påverkar formen och storleken hos skalbaggen grön sköldbagge (Cassida viridis).
Jag studerade tre vilda skalbaggspopulationer och mätte skalbaggars storlek (längd och area), form och livslängd över två generationer. Jag genomförde också predations-experiment för att se hur sannolikt det var att skalbaggarna i dessa populationer skulle bli byten. Med hjälp av dessa undersökningar kunde jag jämföra storlek och livslängd i populationerna för att se om naturlig selektion påverkade storlek eller form.
Mina resultat visade att i den första generationen var skalbaggarnas längd föremål för selektion mot stora (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9176017
- author
- Wendel, Erik
- supervisor
-
- Maja Tarka LU
- Kristina Karlsson LU
- Erica Winslott LU
- organization
- course
- BION03 20222
- year
- 2024
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 9176017
- date added to LUP
- 2024-10-03 13:52:37
- date last changed
- 2024-10-03 13:52:37
@misc{9176017,
abstract = {{Natural selection is an important force behind evolution. It is well known that phenotypic variation provides opportunity for evolution, but research into how selection acts on specific traits over time is lacking. In this thesis, I studied how selection acts upon the shape and body size of the beetle Cassida viridis. Across three populations, I measured size (length and area), shape, and lifespan in two generations of beetles. In addition, I experimentally assessed predation likelihood in the three populations. Using these data, I modeled the differences across populations to determine if selection is acting on these traits. I found that there was disruptive selection on length in the first generation and shape in the second generation across all three populations, potentially due to predation, intraspecific competition, and a tendency for negative directional selection on size. There were also significant differences in survival across populations. However, I observed no correlation between predation intensity and survival. My results suggest that survival may be correlated with the timing of diapause, which may help us understand why insects enter diapause at certain times. This study is the first to explore how natural selection shapes the body size of C. viridis among populations and suggests that C. viridis has proven to be a useful study system to answer questions about how selection shapes populations. Future studies would benefit from including measurements of sexual selection and following the same individuals or generations across their lifecycle.}},
author = {{Wendel, Erik}},
language = {{eng}},
note = {{Student Paper}},
title = {{Natural selection in wild beetle populations}},
year = {{2024}},
}