Browsing by Author "Chelo, Ivo M"
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- Experimental determination of invasive fitness in Caenorhabditis elegansPublication . Chelo, Ivo MEstimation of fitness is a key step in experimental evolution studies. However, no established methods currently exist to specifically estimate how successful new alleles are in invading populations. The main reason is that most assays do not accurately reflect the randomness associated with the first stages of the invasion, when invaders are rare and extinctions are frequent. In this protocol, I describe how such experiments can be done in an effective way. By using the nematode model, Caenorhabditis elegans, a large number of invasion experiments are set up, whereby invading individuals carrying a visual marker are introduced into populations in very low numbers. The number of invaders counted in consecutive generations, together with the number of extinctions, is then used in the context of individual-based computer simulations to provide likelihood (Lk) estimates for fitness. This protocol can take up to five generations of experimental invasions and a few hours of computer processing time.
- Reproductive assurance drives transitions to self-fertilization in experimental Caenorhabditis elegansPublication . Theologidis, Ioannis; Chelo, Ivo M; Goy, Christine; Teotónio, HenriqueEvolutionary transitions from outcrossing between individuals to selfing are partly responsible for the great diversity of animal and plant reproduction systems. The hypothesis of 'reproductive assurance' suggests that transitions to selfing occur because selfers that are able to reproduce on their own ensure the persistence of populations in environments where mates or pollination agents are unavailable. Here we test this hypothesis by performing experimental evolution in Caenorhabditis elegans.
- The role of hermaphrodites in the experimental evolution of increased outcrossing rates in Caenorhabditis elegansPublication . Carvalho, Sara; Chelo, Ivo M; Goy, Christine; Teotónio, HenriqueWhy most organisms reproduce via outcrossing rather than selfing is a central question in evolutionary biology. It has long ago been suggested that outcrossing is favoured when it facilitates adaptation to novel environments. We have previously shown that the experimental evolution of increased outcrossing rates in populations of the male-hermaphrodite nematode Caenorhabditis elegans were correlated with the experimental evolution of increased male fitness. However, it is unknown whether outcrossing led to adaptation, and if so, which fitness components can explain the observed increase in outcrossing rates.
- The role of hermaphrodites in the experimental evolution of increased outcrossing rates in Caenorhabditis elegansPublication . Carvalho, Sara; Chelo, Ivo M; Goy, Christine; Teotónio, HenriqueWhy most organisms reproduce via outcrossing rather than selfing is a central question in evolutionary biology. It has long ago been suggested that outcrossing is favoured when it facilitates adaptation to novel environments. We have previously shown that the experimental evolution of increased outcrossing rates in populations of the male-hermaphrodite nematode Caenorhabditis elegans were correlated with the experimental evolution of increased male fitness. However, it is unknown whether outcrossing led to adaptation, and if so, which fitness components can explain the observed increase in outcrossing rates.