The Homo floresiensis Controversy

A completely new and unexpected quasi human species, Homo floresiensis, nicknamed the Hobbit, was described in 2004 from Liang Bua, a cave in Flores. Like many important new contributions to the human fossil record in the past, many commentators refused to believe that a new species had been discovered, and the type specimen was interpreted as a pathological modern human, usually as a microcephalic dwarf. There is no substance to these claims: close analysis shows that Homo floresiensis is not only a genuinely new species, but that its closest affinities lie with Plio-Pleistocene African species such as Homo habilis, so that it documents an earlier dispersal of hominins from Africa and had hitherto been suspected

The Homo floresiensis Controversy

A completely new and unexpected quasi human species, Homo floresiensis, nicknamed the Hobbit, was described in 2004 from Liang Bua, a cave in Flores. Like many important new contributions to the human fossil record in the past, many commentators refused to believe that a new species had been discovered, and the type specimen was interpreted as a pathological modern human, usually as a microcephalic dwarf. There is no substance to these claims: close analysis shows that Homo floresiensis is not only a genuinely new species, but that its closest affinities lie with Plio-Pleistocene African species such as Homo habilis, so that it documents an earlier dispersal of hominins from Africa and had hitherto been suspected. Key words: Flores Hobbit, Homo floresiensis, Homo erectus, Homo habilis, microcephal

An Overview of the Primates

The order Primates, to which humans belong, is one of the best-known mammalian orders, but there is still much to be learned about its phylogeny and taxonomy. It is clear by now that there are two suborders, Strepsirrhini and Haplorrhini, but beyond that there is still a lot of controversy and misunderstanding including how to operationalise the evolutionary species. The example of the Old World Monkey tribe Cercopithecini is treated in some detail

Current taxonomy and iversity of crown ruminants above the species level

Linnaeus gave us the idea of systematics, with each taxon of lower rank nested inside one of higher rank; Darwin showed that these taxa are the result of evolution; Hennig demonstrated that, if they are to mean anything, all taxa must represent monophyla. He also proposed that, to bring objectivity into the system, each taxonomic rank should be characterised by a particular time depth, but this is not easy to bring about: genera such as Drosophila and Eucalyptus have a time-depth comparable to whole orders among mammals! Within restricted groups of organisms, however, time-depths do tend to vary within limits: we will not do too much violence to current usage if we insist that a modern mammal (including ruminant) genus must have a time-depth of about 5 million years, i.e. going back at least to the Miocene-Pliocene boundary, and a modern family must have a time-depth of about 25 million years, i.e. going back to the Oligocene-Miocene boundary. Molecular studies show that living ruminants present examples where the „traditional“ classification (in the main laid down in the mid-20th-century, and all too often still accepted as standard even today) violates Hennigian principles. Among Bovidae, the genera Bos, Tragelaphus, Gazella and Hemitragus are paraphyletic, and so, among Cervidae, are the genera Cervus and Mazama. I will discuss what we can do about these, and will then present, with commentary, a classification of living ruminants

IMPACTS OF PESTICIDE REGULATION ON THE CALIFORNIA STRAWBERRY INDUSTRY

Environmental regulation of agriculture is becoming increasingly important, and growers are increasingly concerned about the effects of regulations on their profitability. Regulations governing the use of a pesticide affect its economic value. Further, growers often face a choice among pesticide alternatives, each with its own set of regulatory restrictions. In this environment, the introduction of a new regulation can have complex effects on growers' profit-maximizing pesticide choices. Buffer zones and regional emissions caps mean that pesticide choices can have important spatial components. Our paper presents an optimization model that incorporates spatial considerations at the field and regional level. We apply our model to fumigant choice by California strawberry growers. The industry is facing an impending ban on the use of methyl bromide, which in conjunction with chloropicrin was the standard fumigant for over forty years. In addition to the forthcoming ban, the state government has imposed regulations governing methyl bromide application, including buffer zones, etc. These extreme use restrictions provide us with an interesting environment for modeling the effects of pesticide regulations. There are currently two legally available fumigants that may substitute for methyl bromide in strawberries: 1,3-D and chloropicrin. 1, 3-D is subject to township caps and other restrictions. Township caps limit total application in an area. The California Department of Pesticide Regulation is currently undertaking air monitoring and other activities to determine whether or not buffer zones and other restrictions should be applied to chloropicrin. We evaluate the effects of current and proposed regulations on field-level decisions and industry costs and returns. Methodology To the best of our knowledge, no study has examined the role of pesticide use regulations in determining growers' profit-maximizing pesticide choices at the field level. We do so by combining three datasets with a field-level spatial model of the profit-maximizing fumigation decision. The first dataset includes detailed field-level information regarding the costs and yields associated with alternative fumigants obtained from a multi-disciplinary research project. The second includes chemical-specific California use regulations regarding treatment rates, buffer zones, and other restrictions. The third includes information on the shapes and sizes of strawberry fields in California. Using these data, the optimization model computes the profit-maximizing treatment for each field including pattern of treatment and number of acres treated per day, etc. Field-level results are aggregated to evaluate the impact of regional pesticide regulations, and then to estimate the industry-level effects of current and proposed pesticide use regulations. We model the effects of the entire regulatory system on the fumigation decisions made by farmers. The restrictions on fumigants are integrated into a field-level programming model of a grower's fumigant decision choice. The program calculates the optimal fumigation plan for a field, given the field's size and shape, and use regulations, and per-acre costs and returns associated with each fumigant. The resulting field-level choices are aggregated in order to check for consistency with township caps. If caps are exceeded, the model is rerun using a number of allocation rules. All choices for all fields are aggregated in order to obtain industry-level results. We perform this procedure for the current set of restrictions and for several alternative sets, assessing the profitability of each alternative. For example, we remove the existing township caps on 1,3-D and evaluate how much the results change. We include varying buffer zone restrictions on chloropicrin, and evaluate whether growers' fumigant choices are sensitive to the size of the buffer zone. Relevance Environmental regulation of agriculture is becoming increasingly important. By explicitly analyzing the effect of regulations affecting methyl bromide alternatives in a model that includes both the spatial dimensions of some regulations and the costs and yields associated with each alternative, we will obtain a more detailed and accurate assessment of the costs of these regulations than is currently available. Our results will provide a greater understanding of the effects of these regulations on industry profitability, and how these regulations interact. Our model can be applied to other cases of pesticide regulations. Given the increasing importance of environmental regulation in agriculture, it is important to aid policymakers in understanding how regulations interact with each other, possibly in unexpected ways.Environmental Economics and Policy,