Different routes to similar ends
Article Abstract:
Research on Anolis lizard species evolving on the Caribbean islands of the Greater Antilles has involved measuring a range of morphological characters on a number of specimens from each ecomorph on the different islands. It was found that each of 46 species grouped by ecomorph, regardless of its island of origin. Molecular phylogenetic analysis highlighted only two cases where the same ecomorph has evolved twice on an island. It is suggested that, once an ecomorph has evolved on an island, is generally fills the available niche, preventing other species evolving into it.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1998
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The right size for a mammal
Article Abstract:
A comprehensive model of life-history evolution for animals whose growth stops once they reach reproductive maturity is proposed. It combines optimality theory with body-weight scaling of life-history variables. The model shows promise in settling the problem of lopsided frequency distribution of body sizes among species, where a greater number of species are small than large. One of its assumptions is that rates of energy assimilation, respiration and mortality within a species scale with body size, thus generating straight lines on double-logarithmic plots.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1997
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What the sperm count costs
Article Abstract:
Research involving the nematode worm Caenorhabditis elegans (C. elegans) has shown that the generation of excess sperm by male worms can actually decrease the chance of survival. Wayne A. Van Voorhies experimented with mutant male forms of the normally hermaphroditic worms and found that the mutants yielded more sperm than ordinary worms but were less successful at reproduction because their generation times were longer. Hence spermatogenesis appears to affect evolution and the existence of species.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1992
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