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We outline roles of frequency-dependent selection (FDS) in coadaptation and coevolutionary change. Coadaptation and coevolution occur because correlational selection (CS) and correlated evolution couple many traits. CS arises from causal interactions between traits expressed in two or more interactors, which invariably involve different traits (signalers-receivers). Thus, the causes of CS are due to FDS acting on trait interactions. Negative FDS, a rare advantage, is often coupled to positive FDS generating complex dynamics and FD cycles. Neural mechanisms of learning and perception create analogous mutes by which traits are reinforced in cognitive and perceptual systems of interactors, substituting for positive FDS. FDS across all levels of biological organization is thus best understood as proximate causes that link interactors and shape genetic correlations within and among interactors on long timescales, or cognitive trait correlations within interactors on short timescales. We find rock-paper-scissors dynamics are common in nature. [ABSTRACT FROM AUTHOR]

This article presents a review on the existing techniques for manipulating biological cells. Because biomanipulation involves a wide range of disciplines, from biology to engineering, we concentrate on some of the key methodologies that would result in an efficient biomanipulation system. Some of the key methodologies discussed in this article for cell manipulation relate to the use of magnetics, microelectromechanical systems (MEMS)-based approaches, optics, electric field, and mechanical techniques. Recent advances in engineering have allowed researchers worldwide to address the problems arising from conventional manipulation techniques. This paper assimilates significance and limitations of biomanipulation techniques described in the literature. [ABSTRACT FROM AUTHOR]

Electrophoretic separation of a mixture of chemical species is a fundamental technique of great usefulness in biology, health care, and forensics. In capillary electrophoresis (which has evolved from its predecessor, slab-gel electrophoresis), the sample migrates through a single microcapillary instead of through the network of pores in a gel. A fundamental design problem is to minimize dispersion in the separation direction. Molecular diffusion is inevitable and sets a theoretical limit on the best separation that can be achieved. But in practice, there are a number of effects arising out of the interplay between fluid flow, chemistry, thermal effects, and electric fields that result in enhanced dispersion. This paper reviews the subject of fluid flow in such capillary microchannels and examines the various causes of enhanced dispersion that limit the efficiency of separation. [ABSTRACT FROM AUTHOR]

About 20 years ago, DNA sequences were separately described from the quagga (a type of zebra) and an ancient Egyptian individual. What made these DNA sequences exceptional was that they were derived from 140- and 2400-year-old specimens. However, ancient DNA research, defined broadly as the retrieval of DNA sequences from museum specimens, archaeological finds, fossil remains, and other unusual sources of DNA, only really became feasible with the advent of techniques for the enzymatic amplification of specific DNA sequences. Today, reports of analyses of specimens hundreds, thousands, and even millions of years old are almost common-place. But can all these results be believed? In this paper, we critically assess the state of ancient DNA research. In particular, we discuss the precautions and criteria necessary to ascertain to the greatest extent possible that results represent authentic ancient DNA sequences. We also highlight some significant results and areas of promising future research. [ABSTRACT FROM AUTHOR]

In this paper I review the three best-known aspects of community structure in the deep-sea benthos: depth gradients of species diversity, spatial dispersion, and faunal replacement with depth. Patterns of species diversity are documented for the megafaunal invertebrates and fishes and four macrofaunal taxa (bivalves, gastropods, cumaceans, and polychaetes). These trends and data on spatial dispersion provide the basis for evaluating theories of species diversity in the deep sea. I then compare rates of species replacement with depth in megafaunal and macrofaunal elements, and relate differences between the groups to life-history parameters and trophic roles. [ABSTRACT FROM AUTHOR]

Intraspecific predation, the process of both killing and eating an individual of the same species, is a significant and widespread process that until recently has not received the attention it merits. It is a major factor in the biology of many species and may influence population structure, life history, competition for mates and resources, and behavior. It is commonly observed among many animals: For this review I read over 900 papers describing such predation in about 1300 species. Laurel Fox's (1975 review of cannibalism (54) should be read for additional information. Here I attempt to present new or different data, references, and ideas. One of my purposes is to establish a theoretical framework for the organization and interpretation of the numerous observations of intraspecific predation. Certain topics included here are speculation intended to spark interest and indicate important problems that need further research. [ABSTRACT FROM AUTHOR]

In this review, I address primarily the question whether the synthetic theory of population genetics, ecology and evolution supplies a sufficient explanation of what we find. The omission of a paper from the present bibliography is not intended as a criticism; for others, see the general review of Heliconius biology (23) and the comprehensive bibliographies (22, 105). There has always been a free exchange of data and ideas among Heliconius researchers, and some important discoveries and ideas have occurred simultaneously and independently; some foundation work is in unpublished theses (3, 22, 50, 51, 76, 85, 94). [ABSTRACT FROM AUTHOR]