Philosophy Dictionary of ArgumentsHome
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| Species: In biology, a species is a fundamental unit of classification. It groups together organisms that can interbreed and produce fertile offspring, sharing common characteristics and occupying a specific ecological niche. See also Niches, Evolution, Genes, Natural Kinds._____________Annotation: The above characterizations of concepts are neither definitions nor exhausting presentations of problems related to them. Instead, they are intended to give a short introduction to the contributions below. – Lexicon of Arguments. | |||
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Stephen Jay Gould on Species - Dictionary of Arguments
I 223 Species/Gould: an average invertebrate species lived about 5 - 10 million years unchanged. It hardly changes in time and dies out without successors. At a higher level, evolution is basically a matter of the different successes of species and not a slow transformation of lineages. - - - II 331 Species/Gould: Definition species: species are defined as populations isolated from all others in reproduction. When brought together with other species, they will not mix. Key question for the origin of a new species: how do isolation mechanisms develop? II 332 Traditional point of view: an originally unified population is separated from continents by drifting apart, by newly formed mountain ranges, the newly isolated groups would adapt to their new environment by adaptation. After a certain time, the populations become so different that they can no longer be crossed. New view: the ultimate success of a species may depend on the evolution of adaptation, but the act of species formation itself can be a coincidental event. Taxonomists have discovered that many groups of closely related species are not very different in form, behavior, and even in genetic equipment. However, there are striking differences in the number and shape of chromosomes, and these differences produce the isolation mechanisms that they receive as a separate species. The main change occurs in a single individual. Who should it breed with? - - - IV 198 Species: biodiversity has certainly increased over time. Today's oceans contain at least twice as many species as the oceans in the Palaeozoic. Therefore, one could expect that they not only contain more species, but also more diverse species of organisms, with fundamentally different blueprints. But this is not the case! Today, twice as many species are put in much fewer groups of higher taxa. Today's seas are dominated by fewer groups: primarily by mussels, snails, crabs, fish and sea urchins. Each group includes many more species than any tribe in the Palaeozoic ever had. This steady decrease of organic construction types with a strong increase in the number of species is probably the most prominent trend of fossil documents! IV 199 Causality/coincidence/evolution: there may be one principle that can be identified: "initial experimentation and later standardization". For example, around 1900 there were few car brands and a much wider range of construction types. Today, there are hundreds of brands and much more uniform construction. Evolution/species richness: the change from a few species and many groups to a few groups and many species would occur even in the case of purely coincidental extinction if every speciation process at the beginning of life's history had been accompanied by average major changes. IV 201 Extinction: each is inevitable forever. An extinct experiment will never be repeated. The chances are mathematically too slim. Biologists speak of the "principle of the irreversibility of evolution". Order/coincidence/Gould: coincidental processes produce a high degree of order. The fact that they result in certain patterns does not speak against their coincidence. IV 327 Species/Gould: each species is a concatenation of improbabilities. Every species, whether human, coral or squid, is the last link in a chain that stretches back to the beginning of life. If any of these species had died out or evolved in any other direction, the end results would be very different. For example, our ancestors, the fish, developed a special fin with a stable, central bony axis. Without them, they could not have developed ashore. Nevertheless, these fins did not develop in anticipation of the necessities of rural life. They developed as adaptations to a local habitat. Necessity: human brains did not develop on a direct and necessary ascending ladder, but on winding paths full of accidents. - - - III 264 Species/Gould: in the early days of evolution, the greatest spectrum of forms was reached, and most of the early experiments were extinct. It was accidental and not by predictable causes. Today, there are only a small number of possibilities left. >Evolution, >Explanation, >Darwinism._____________Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution. Translations: Dictionary of Arguments The note [Concept/Author], [Author1]Vs[Author2] or [Author]Vs[term] resp. "problem:"/"solution:", "old:"/"new:" and "thesis:" is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition. |
Gould I Stephen Jay Gould The Panda’s Thumb. More Reflections in Natural History, New York 1980 German Edition: Der Daumen des Panda Frankfurt 2009 Gould II Stephen Jay Gould Hen’s Teeth and Horse’s Toes. Further Reflections in Natural History, New York 1983 German Edition: Wie das Zebra zu seinen Streifen kommt Frankfurt 1991 Gould III Stephen Jay Gould Full House. The Spread of Excellence from Plato to Darwin, New York 1996 German Edition: Illusion Fortschritt Frankfurt 2004 Gould IV Stephen Jay Gould The Flamingo’s Smile. Reflections in Natural History, New York 1985 German Edition: Das Lächeln des Flamingos Basel 1989 |
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Ed. Martin Schulz, access date 2024-04-29