Molluscs essay

Molluscs essay - Molluscs are included in the phylum...

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Molluscs are included in the phylum Mollusca and they are a very diverse phylum of soft-bodied animals that can be found in fresh water, marine, and terrestrial environments. There are over 10,000 species of molluscs that live in various habitats that have selected for feeding and locomotion adaptations, structures, and behaviors that allow the different molluscs to survive. Anatomical key characteristics of molluscs are a soft, unsegmented body enclosed by a mantle, a large ventral foot and the radula. The theory of a hypothetical ancestral mollusc (HAM) allows one to examine molluscs today as descendants from an ancestral type. This theory suggests that the diversity of molluscs has arisen by modifications to a single ancestor because all molluscs share the same general body plan, but have modified in many different ways specific to the different classes. Therefore, each different class of mollusc has different modifications to this general body plan that represents adaptations to their different habitats. The HAM theory can be utilizes to support how the tertiary snail and the squid come from a single, common ancestor, however, have attained diverse characteristics and structures as a result of natural selection leading to the adaptation of molluscs over time. A long-term adaptation is any heritable aspect of form, function, behavior, or development that
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This note was uploaded on 03/20/2008 for the course BIOL 101L taught by Professor Stengaga during the Fall '08 term at UNC.

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Molluscs essay - Molluscs are included in the phylum...

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