Apparently ancient DNA has been reported from amber-preserved insects many millions of years old. Rigorous attempts to reproduce these DNA sequences from amber- and copal-preserved bees and flies have failed to detect any authentic ancient insect DNA. Lack of reproducibility suggests that DNA does not survive over millions of years even in amber, the most promising of fossil environments.

Ancient DNA sequences are able to offer valuable insights into molecular evolutionary processes, which are not directly accessible via modern DNA. They are particularly suitable for the estimation of substitution rates because their ages provide calibrating information in phylogenetic analyses, circumventing the difficult task of choosing independent calibration points. The substitution rates o...

Recently, the geographical origins of Ashkenazic Jews (AJs) and their native language Yiddish were investigated by applying the Geographic Population Structure (GPS) to a cohort of exclusively Yiddish-speaking and multilingual AJs. GPS localized most AJs along major ancient trade routes in northeastern Turkey adjacent to primeval villages with names that resemble the word "Ashkenaz." These find...

DNA sequences extracted from preserved remains can add considerable resolution to inference of past population dynamics. For example, coalescent-based methods have been used to correlate declines in some arctic megafauna populations with habitat fragmentation during the last ice age. These methods, however, often fail to detect population declines preceding extinction, most likely owing to a co...

The study of human evolution has been revolutionized by inferences from ancient DNA analyses. Key to these studies is the reliable estimation of the age of ancient specimens. High-resolution age estimates can often be obtained using radiocarbon dating, and, while precise and powerful, this method has some biases, making it of interest to directly use genetic data to infer a date for samples tha...

DNA that survives in museum specimens, bones and other tissues recovered by archaeologists is invariably fragmented and chemically modified. The extent to which such modifications accumulate over time is largely unknown but could potentially be used to differentiate between endogenous old DNA and present-day DNA contaminating specimens and experiments. Here we examine mitochondrial DNA sequence...

Much of the macroeconomic analysis in Ethiopia is hardly linked to the country’s pioneer development thinkers. The latter, however, articulated the Ethiopian development problems and what should be the appropriate policy direction to address them nearly a century ago. This articulated development thinkers of the early 20 th century Ethiopia had captured the imagination of prominent Ethiopian hi...

Optimal normal bases are special cases of the so-called Gauss periods (Disquisitiones Arithmeticae, Articles 343-366); in particular, optimal normal bases are Gauss periods of type (n,1) for any characteristic and type (n,2) for characteristic 2. We present the multiplication tables and complexities of Gauss periods of type (n, t) for all n and t = 3,4,5 over any finite field and give a slightl...

This paper contributes to the knowledge about how educational investments are allocated across siblings within the household. More specifically I focus on investigating whether there are signs of diversification, formal schooling being a risky investment. The data used is unusual in that it includes the head of household’s risk preferences in addition to school-related and other information. Th...

Core assets are reusable artifacts built to be used in different software products in the same family. As such, core assets need to capture both commonality that exists and variability that is allowed in the product family (line). These assets are later utilized for guiding the creation of particular valid products in the family. Feature-oriented and UML-based methods have been proposed for mod...