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Evolution of fish to tetrapods. The basic body plan has been phylogenetically constrained. Most terrestrial vertebrates have a body plan that consist of four limbs. The phylogenetic inertia hypothesis suggests that this body plan is observed, not because it happens to be optimal, but because tetrapods are derived from a clade of fishes (Sarcopterygii) which also have four limbs.
Marine larval ecology is the study of the factors influencing dispersing larvae, which many marine invertebrates and fishes have. Marine animals with a larva typically release many larvae into the water column, where the larvae develop before metamorphosing into adults.
Therefore, they are rarely found by the entomologists specialized in sawflies. Only for few species the larval biology is known. Orussidae are parasitoids of xylobiontic larvae of beetles or Hymenoptera, particularly of the larvae of jewel beetles (Buprestidae), long-horned beetles (Cerambycidae), and wood wasps (Siricidae, Xiphydriidae).
Thorson's rule (named after Gunnar Thorson by S. A. Mileikovsky in 1971) [1] is an ecogeographical rule which states that benthic marine invertebrates at low latitudes tend to produce large numbers of eggs developing to pelagic (often planktotrophic [plankton-feeding]) and widely dispersing larvae, whereas at high latitudes such organisms tend to produce fewer and larger lecithotrophic (yolk ...
Phylogenetic comparative methods (PCMs) use information on the historical relationships of lineages (phylogenies) to test evolutionary hypotheses. The comparative method has a long history in evolutionary biology; indeed, Charles Darwin used differences and similarities between species as a major source of evidence in The Origin of Species .
Biological constraints are factors which make populations resistant to evolutionary change. One proposed definition of constraint is "A property of a trait that, although possibly adaptive in the environment in which it originally evolved, acts to place limits on the production of new phenotypic variants."
In the most recent research, the three phyla Cycliophora, Entoprocta and Bryozoa makes up a single clade and are the first to branch off from the other lophotrochozoans. The second split is the molluscs, and the third consists of two sister phyla, annelids and nemerteans. Lastly remains the clade that consist of the phoronids and the brachiopods.
However, as found by Rebecci et al. in their 2020 study, desiccation is a major selective force in only terrestrial environments, which the larva will combat by dauer dormancy. [19] Phylogenetic analysis of nematodes suggests that parasitic lineages are derived overwhelmingly from terrestrial ancestors, even with lineages that reside in water.