Asexual reproduction is one of the most important traits in the evolutionary history of corals. No real-time observations of asexual reproduction in azooxanthellate solitary scleractinian corals have been conducted to date. Here, we describe previously unknown aspects of asexual reproduction by using Truncatoflabellum spheniscus (Family Flabellidae) based on observations of transverse division ...

The maintenance of sex is an unresolved paradox in evolutionary biology, given the inherent twofold fitness advantage for asexuals. Parasitic helminths offer a unique opportunity to address this enigma. Parasites that can create novel antigenic strains are able to escape pre-existing host immunity. Viruses produce diversity through mutation with rapid clonal proliferation. The long generation t...

We consider the evolutionary basis of intertemporal choice and time discounting, in particular, when there are intergenerational transfers. We show that the notion of “reproductive value” from biology provides the utility criterion for a parent to optimize the allocation of resources between transfers to offspring and for promoting her own survival to the next period. This optimization has a na...

The aims of this study were to determine (i) whether adaptation under strong selection occurred through mutations in a narrow target of one or a few nucleotide sites or a broad target of numerous sites and (ii) whether the programs of adaptation previously observed from three experimental populations were unique or shared among populations that underwent parallel evolution. We used archived pop...

Asexuality is rare in animals in spite of its apparent advantage relative to sexual reproduction, indicating that it must be associated with profound costs [1-9]. One expectation is that reproductive advantages gained by new asexual lineages will be quickly eroded over time [3, 5-7]. Ancient asexual taxa that have evolved and adapted without sex would be "scandalous" exceptions to this rule, bu...

BACKGROUND AND AIMS Differences in competitive ability between the sexes of dioecious plants are expected as a result of allocation trade-offs associated with sex-differential reproductive costs. However, the available data on competitive ability in dioecious plants are scarce and contradictory. In this study sexual competition was evaluated using the dioecious plant Antennaria dioica in a comm...

I show that the natural selection of metabolism and mass can select for the major life-history and allometric transitions that define lifeforms from viruses, over prokaryotes and larger unicells, to multicellular animals. The proposed selection is driven by a mass-specific metabolism that is selected as the pace of the resource handling that generates net energy for self-replication. An initial...

The reproductive mode of facultative parthenogens allows recessive mutations that accumulate during the asexual phase to be unmasked following sexual reproduction. Longer periods of asexual reproduction should increase the accumulation of deleterious mutations within individuals, reduce population-level genetic diversity via competition and increase the probability of mating among close relativ...

The hawk-dove game famously introduced strategic game theory thinking into biology and forms the basis of arguments for limited aggression in animal populations. However, aggressive 'hawks' and peaceful 'doves', with strategies inherited in a discrete manner, have never been documented in a real animal population. Thus, the applicability of game-theoretic arguments to real populations might be ...

Sex is by far the most predominant mode of reproduction among eukaryotes. Nevertheless, two new discoveries of asexual reproduction in a lizard and a plant from the Australian arid zone highlight an emerging trend toward the loss of sex in this region. Efforts to understand the processes leading to this pattern should provide important information about the relative advantages and disadvantages...