Malayan Animal Life

The power of locomotion is, perhaps, one of the most striking attributes of animal life. It occurs in all groups of animals and is characterized by two conspicuous features: (i) In no other biological activity is an animal brought into closer and more intimate contact with its environment. (ii) Closely related animals may display striking differences of locomotory pattern yet in every cast the animal is able to deal precisely and efficiently with mechanical problems of great complexity. For many years, the study of animal locomotion has been concerned with two, apparently distinct, types of problems. First, attention has been paid to the mechanical or kinematic principles which animals employ in order to progress from one place to another. In many terrestrial animals these principles are relatively simple, for their limbs represent levers of one type or another; in other cases the mechanical principles are more obscure—we know little concerning the kinematics of movement of a fish or a snail, and little or nothing of the forces which propel a bird actively through the air. These problems have long attracted attention and it is encouraging to know that they are now being attacked by methods as precise and as controlled as those employed by aeronautical or marine engineers. The second type of problem is of a different nature; it is concerned with physiological nature of the locomotory machine. What is the nature of the neuro-muscular mechanism which enables and animal to utilize its muscular energy with such conspicuous precision and efficiency? How far are the movements dependent on the higher nervous centres, and how far are they dependent on the receipt of time signals from the outside world?

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Phanerozoic trends in the global geographic disparity of marine biotas

Paleobiology ◽

10.1666/0094-8373-35.4.612 ◽

2009 ◽

Vol 35 (4) ◽

pp. 612-630 ◽

Cited By ~ 26

Author(s):

Arnold I. Miller ◽

Devin P. Buick ◽

Katherine V. Bulinski ◽

Chad A. Ferguson ◽

Austin J. W. Hendy ◽

...

Keyword(s):

Geographic Distance ◽

Marine Biodiversity ◽

Marine Animal ◽

Animal Life ◽

Data Repositories ◽

Geographic Disparity ◽

The Family ◽

Family Level ◽

History Of

Previous analyses of the history of Phanerozoic marine biodiversity suggested that the post-Paleozoic increase observed at the family level and below was caused, in part, by an increase in global provinciality associated with the breakup of Pangea. Efforts to characterize the Phanerozoic history of provinciality, however, have been compromised by interval-to-interval variations in the methods and standards used by researchers to calibrate the number of provinces. With the development of comprehensive, occurrence-based data repositories such as the Paleobiology Database (PaleoDB), it is now possible to analyze directly the degree of global compositional disparity as a function of geographic distance (geo-disparity) and changes thereof throughout the history of marine animal life. Here, we present a protocol for assessing the Phanerozoic history of geo-disparity, and we apply it to stratigraphic bins arrayed throughout the Phanerozoic for which data were accessed from the PaleoDB. Our analyses provide no indication of a secular Phanerozoic increase in geo-disparity. Furthermore, fundamental characteristics of geo-disparity may have changed from era to era in concert with changes to marine venues, although these patterns will require further scrutiny in future investigations.

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