Search results for "Diversification"

2020

Understanding how and why rates of evolutionary diversification vary is a key issue in evolutionary biology, ecology, and biogeography. Evolutionary rates are the net result of interacting processes summarized under concepts such as adaptive radiation and evolutionary stasis. Here, we review the central concepts in the evolutionary diversification literature and synthesize these into a simple, general framework for studying rates of diversification and quantifying their underlying dynamics, which can be applied across clades and regions, and across spatial and temporal scales. Our framework describes the diversification rate (d) as a function of the abiotic environment (a), the biotic envir…

Next-generation cophylogeny: unravelling eco-evolutionary processes

2021

A fundamental question in evolutionary biology is how microevolutionary processes translate into species diversification. Cophylogeny provides an appropriate framework to address this for symbiotic associations, but historically has been primarily limited to unveiling patterns. We argue that it is essential to integrate advances from ecology and evolutionary biology into cophylogeny, to gain greater mechanistic insights and transform cophylogeny into a platform to advance understanding of interspecific interactions and diversification more widely. We discuss key directions, such as incorporating trait reconstruction and considering multiple scales of network organization, and highlight rece…

The roles of whole-genome and small-scale duplications in the functional specialization of Saccharomyces cerevisiae genes

2013

Researchers have long been enthralled with the idea that gene duplication can generate novel functions, crediting this process with great evolutionary importance. Empirical data shows that whole-genome duplications (WGDs) are more likely to be retained than small-scale duplications (SSDs), though their relative contribution to the functional fate of duplicates remains unexplored. Using the map of genetic interactions and the re-sequencing of 27 Saccharomyces cerevisiae genomes evolving for 2,200 generations we show that SSD-duplicates lead to neo-functionalization while WGD-duplicates partition ancestral functions. This conclusion is supported by: (a) SSD-duplicates establish more genetic i…

Early ontogeny defines the diversification of primary vascular bundle systems in angiosperms

2020

AbstractUnderstanding vascular bundle systems in angiosperms is a challenge. On the one hand, the vascular tissue is extremely important in reconstructing the evolution and survivability of plants, but on the other hand, it forms a complicated three-dimensional system of controversially discussed phylogenetic and ontogenetic origin. To increase clarity, in this paper we briefly summarize histological, phylogenetic and molecular aspects of primary vascular bundle formation in angiosperms, adding histological data on early stages of vascular bundle formation, proposing a concept combining the different views and providing simplified illustrations to improve the understanding of primary vascul…

“Into and Out of” the Qinghai‐Tibet Plateau and the Himalayas: Centers of origin and diversification across five clades of Eurasian montane and alpin…

2020

Abstract Encompassing some of the major hotspots of biodiversity on Earth, large mountain systems have long held the attention of evolutionary biologists. The region of the Qinghai‐Tibet Plateau (QTP) is considered a biogeographic source for multiple colonization events into adjacent areas including the northern Palearctic. The faunal exchange between the QTP and adjacent regions could thus represent a one‐way street (“out of” the QTP). However, immigration into the QTP region has so far received only little attention, despite its potential to shape faunal and floral communities of the QTP. In this study, we investigated centers of origin and dispersal routes between the QTP, its forested m…

Active Wild Food Practices among Culturally Diverse Groups in the 21st Century across Latgale, Latvia

2021

Simple Summary A study in the bordering region of Latvia took place in order to investigate wild plant food uses. In total 72 interviewees reported food uses. The most represented uses of recorded plants were recreational tea; for jam; as snacks and soup; and drink. Interviewees also reported loss of foraging practice due to the habitat change as for example in case of caraway and chamomile. The results indicated that part of the reason for the main use of wild plants were linked to diet diversification. Abstract Local ecological knowledge (LEK), including but not limited to the use of wild food plants, plays a large role in sustainable natural resource management schemes, primarily due to …

Grading investment diversification options in presence of non-historical financial information

2021

Modern portfolio theory deals with the problem of selecting a portfolio of financial assets such that the expected return is maximized for a given level of risk. The forecast of the expected individual assets’ returns and risk is usually based on their historical returns. In this work, we consider a situation in which the investor has non-historical additional information that is used for the forecast of the expected returns. This implies that there is no obvious statistical risk measure any more, and it poses the problem of selecting an adequate set of diversification constraints to mitigate the risk of the selected portfolio without losing the value of the non-statistical information owne…

Shared language, diverging genetic histories: high-resolution analysis of Y-chromosome variability in Calabrian and Sicilian Arbereshe.

2015

The relationship between genetic and linguistic diversification in human populations has been often explored to interpret some specific issues in human history. The Albanian-speaking minorities of Sicily and Southern Italy (Arbereshe) constitute an important portion of the ethnolinguistic variability of Italy. Their linguistic isolation from neighboring Italian populations and their documented migration history, make such minorities particularly effective for investigating the interplay between cultural, geographic and historical factors. Nevertheless, the extent of Arbereshe genetic relationships with the Balkan homeland and the Italian recipient populations has been only partially investi…

Computational Fluid Dynamics Suggests Ecological Diversification among Stem-Gnathostomes.

2020

Summary The evolutionary assembly of the vertebrate bodyplan has been characterized as a long-term ecological trend toward increasingly active and predatory lifestyles, culminating in jawed vertebrates that dominate modern vertebrate biodiversity [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. This contrast is no more stark than between the earliest jawed vertebrates and their immediate relatives, the extinct jawless, dermal armor-encased osteostracans, which have conventionally been interpreted as benthic mud-grubbers with poor swimming capabilities and low maneuverability [ 9 , 10 , 11 , 12 ]. Using computational fluid dynamics, we show that osteostracan headshield morphology is compatible with a dive…

An Easy Game? Experiences of ‘Homecoming’ in the Post-Socialist Context of Croatia and the Czech Republic

2016

The obstacles that often accompany remigration, planned and imagined as a ‘homecoming’, are seldom the topic of investigation in migration studies. Returning is not always an ‘easy game’. To explore this aspect of remigration, this chapter intends to focus on narratives of return produced mainly by so-called co-ethnic migrants who moved back to Croatia and the Czech Republic during the past two decades of post-socialist transformation. The empirical base of the chapter draws on the experiences and struggles accompanying remigration, and of arrival and acceptance in the respective society as described by returnees in biographical interviews. Attention is given to everyday social interaction …