1981 11 05 Nature - Vol 294 - Ben Zuckerman

Magazine Overview

This issue of Nature, dated 5 November 1981, features a cover story titled "Extraterrestrials — Where are they?" by Ben Zuckerman. The magazine also includes articles on genetic research, specifically the integration of foreign genes into mammals, and a discussion on the scientific and policy aspects of searching for extraterrestrial intelligence.

Genetic Engineering: Rabbit Beta-Globin Genes in Mice

The issue begins with a detailed examination of research involving the presence of rabbit beta-globin genes in mice. Nine out of ten mice contained these genes, with copy numbers varying significantly. Further experiments showed that six out of eighteen progeny from positive males also contained rabbit globin sequences, suggesting a pattern of inheritance consistent with a chromosomal location. In situ hybridization experiments indicated that most copies of the rabbit globin genes were located in the middle of one of the homologues of chromosome 1. The integration of these foreign genes into the mouse genome and their expression are discussed, with a study by Wagner and colleagues at Ohio University suggesting that at least the first goal – stable integration and correct temporal and tissue-specific expression – has been achieved. Some mice derived from eggs injected with a rabbit beta-globin gene were found to contain the polypeptide in their erythrocytes, and this was also true for their progeny. The wider implications of this research point towards the potential for genetic manipulation of agriculturally important animals.

Extraterrestrials — Where are they?

This cover story by Ben Zuckerman explores the scientific and philosophical debate surrounding the existence of extraterrestrial civilizations. Zuckerman discusses the 'optimistic' view, championed by scientists like Carl Sagan, Philip Morrison, and Frank Drake, which suggests that 100,000 or more technical civilizations may exist in the Milky Way. This view is often supported by the 'Drake equation,' which attempts to quantify the number of such civilizations based on various probabilities. Zuckerman critically examines the estimations used in the Drake equation, particularly the probability of life originating and evolving to intelligence. He notes that while many scientists find the arguments for a very small number of civilizations compelling, few abandon the search for signals. The article also highlights the political aspect, mentioning Senator William Proxmire's efforts to prohibit federal funds for NASA's modest radio search program, arguing that it was an inefficient use of resources and suggesting that intelligent life might be found closer to home. The decision to cut funding for 1982 is deemed unfortunate due to public interest and the broader implications for American science funding decisions.

Histone Gene Organization: Paradigm Lost

Another significant article, "Histone gene organization: paradigm lost" by Larry Kedes and Rob Maxson, discusses recent findings that challenge established notions about histone gene organization. Previously, it was believed that histone genes in sea urchins and Drosophila melanogaster were remarkably similar, repeated in hundreds of tandem units. However, new reports indicate different patterns in various vertebrate species, with genes appearing scattered and solitary, separated by long stretches of non-histone DNA. This dispersion is speculated to be associated with evolutionary drift in gene sequence. The article notes that while some coding regions remain clustered, they are not arranged in clean-cut tandem repeats, and each coding region is present in only tens per haploid genome. The authors' own laboratory findings suggest that the distinction between clustered and dispersed histone gene organization is not strictly interspecies. They observe a shift in sea urchin development where an 'early' gene set is reduced in favor of 'late' histone genes, which are scattered and shuffled, similar to vertebrate examples. The article concludes that genes coding for isoforms of the same histone exhibit extensive nucleotide sequence divergence, and not all vertebrate genes follow the same model, complicating the understanding of histone gene evolution.

Discussion and Implications

The issue touches upon the broader implications of these scientific advancements. The genetic engineering research opens doors for understanding gene expression and potentially manipulating agricultural animals. The debate on extraterrestrial intelligence highlights the intersection of scientific inquiry, public interest, and political decision-making regarding research funding. The findings on histone gene organization underscore the dynamic and evolving nature of biological understanding, where established paradigms are constantly being revised by new evidence.

Recurring Themes and Editorial Stance

This issue of Nature reflects a commitment to reporting on cutting-edge scientific research across diverse fields, from molecular biology and genetics to astrophysics and astrobiology. The editorial stance appears to be one of rigorous scientific inquiry, critical analysis of evidence and arguments, and an awareness of the societal and political contexts in which science operates. The inclusion of articles on both fundamental biological processes and speculative scientific questions like the existence of extraterrestrial life suggests a broad scope and an interest in topics that engage both the scientific community and the public imagination. The critical examination of scientific claims, as seen in the discussion of the Drake equation and the challenges to the histone gene paradigm, demonstrates a dedication to scientific accuracy and intellectual honesty.