The fossil record suggests that modern human morphology evolved in Africa between 150,000 and 50,000 years ago, when the sole inhabitants of Eurasia were the Neanderthals and other equally nonmodern people. However, the earliest modern or near-modern Africans were behaviorally (archaeologically) indistinguishable from their nonmodern, Eurasian contemporaries, and it was only around 50,000-40,00...

For untold millennia certain animals have used ultrasound to probe places where light is unavailable, echo-locating bats being among the most adept. With ultrasonics, bats can quickly and safely 'see' at night in pursuing insects or flying in dark caves. Unable to hear ultrasound, humans have nevertheless made use of it. They did this anciently by taming wolves, with their keen ultrasonic heari...

sumption that libido is basically pleasure-seeking, and proposes instead Fairbairn's view that it seeks contact with objects: for example, the infant's mouth becomes erotized because it is the route toward, or the bodily structure for, contacting the libidinally desired object (the breast). Stanton, in discussing object choice, would add knowledge of social and group behavior theory to the trad...

The aim of this study is to measure human mitochondrial sequence variability in the relatively slowly evolving mitochondrial gene cytochrome oxidase subunit II (COII) and to estimate when the human common ancestral mitochondrial type existed. New COII gene sequences were determined for five humans (Homo sapiens), including some of the most mitochondrially divergent humans known; for two pygmy c...

In order to examine the possibility of multiple founding populations of anatomically modern Homo sapiens, we collected DNA sequence data from 10 X-chromosomal regions, 5 autosomal regions, and 1 Y-chromosomal region, in addition to mitochondrial DNA. Except for five regions which are genealogically uninformative and two other regions for which chimpanzee orthologs are not available, the ancestr...

Archaeology's main contribution to the debate over the origins of modern humans has been investigating where and when modern human behavior is first recognized in the archaeological record. Most of this debate has been over the empirical record for the appearance and distribution of a set of traits that have come to be accepted as indicators of behavioral modernity. This debate has resulted in ...

A review of genetic evidence leads to the following conclusions concerning human population history: (1) Between 33,000 and 150,000 years ago the human population expanded from an initial size of perhaps 10,000 breeding individuals, reaching a size of at least 300,000. (2) Although the initial population was small, it contained at least 1000 breeding individuals. (3) The human races separated s...

T he expansion of modern humans over the planet is one of the most spectacular events in the course of human evolution. During millions of years, distinctive forms of hominins evolved in parallel and sometimes coexisted in the same regions. Between 60,000 and 40,000 y ago, one species expanded out of its African birthplace and replaced all others. The Neanderthals are the best-known archaic hum...

Let X ∈ R denote a random stock market return vector, where Xj is the value of a one unit investment in stock j at the end of the trading day. We require that Xj ≥ 0 for j = 1, 2, . . . , m, that is, an investor cannot lose more than the invested capital. Let b, bj ≥ 0, ∑m j=1 bj = 1, denote a portfolio, that is, an allocation of investor’s capital across the investment alternatives. Let B deno...

discussion recently about life-cycle funds and their role in providing a secure retirement income for older Americans. These funds, which gradually shift account assets from broad-based stock funds to bond funds as a participant ages, are becoming an important vehicle for retirement savings. This policy brief explores the economic rationale behind the life-cycle approach and the advantages and ...