Species Problem - Quotations On The Species Problem

Quotations On The Species Problem

"... I was much struck how entirely vague and arbitrary is the distinction between species and varieties" Darwin 1859 (p. 48)

"No term is more difficult to define than "species," and on no point are zoologists more divided than as to what should be understood by this word". Nicholson (1872) p. 20

"Of late, the futility of attempts to find a universally valid criterion for distinguishing species has come to be fairly generally, if reluctantly, recognized" Dobzhansky (1937) p. 310

"The concept of a species is a concession to our linguistic habits and neurological mechanisms" Haldane (1956)

"The species problem is the long-standing failure of biologists to agree on how we should identify species and how we should define the word 'species'." Hey (2001)

"First, the species problem is not primarily an empirical one, but it is rather fraught with philosophical questions that require - but cannot be settled by - empirical evidence." Pigliucci (2003)

"An important aspect of any species definition whether in neontology or palaeontology is that any statement that particular individuals (or fragmentary specimens) belong to a certain species is an hypothesis (not a fact)"

"We show that although discrete phenotypic clusters exist in most genera (>80%), the correspondence of taxonomic species to these clusters is poor (<60%) and no different between plants and animals. ... Contrary to conventional wisdom, plant species are more likely than animal species to represent reproductively independent lineages."