caa a22 4500 386384711 CHVBK 20180307112055.0 cr unu---uuuuu 161130s1989 xx s 000 0 eng 10.1017/S0263593300028649 doi S0263593300028649 pii (NATIONALLICENCE)cambridge-10.1017/S0263593300028649 Little Colin Department of Zoology, Bristol University, Bristol BS8 1UG, U.K. Comparative physiology as a tool for investigating the evolutionary routes of animals on to land [Elektronische Daten] [Colin Little] Although many physiological characteristics are very labile, it is proposed that some are stable enough to provide evidence concerning the routes by which terrestrial animals moved on to land. Osmotic tolerance and osmoregulatory ability are investigated first. Marine littoral invertebrates tolerate wide osmotic changes but osmoregulate little. Freshwater invertebrates osmoregulate well, but over a narrow range. Terrestrial prosobranchs of the family Pomatiasidae, which have wide tolerance, may have originated directly from the sea. The Cyclophoridae, which are intolerant, may have moved to land from fresh water. Isopods and talitrid amphipods may all have had direct marine origins with no freshwater phase. Secondly, terrestrial animals of marine origin may have blood with higher osmotic pressures than those passing through fresh water. In prosobranchs, isopods and amphipods, the evidence agrees with the conclusions suggested from character one. Thirdly, the production of hypo-osmotic urine in terrestrial animals may be evidence of freshwater origin. The evidence again supports the initial suggestions about prosobranchs and amphipods. It is concluded that because there is little selection pressure acting on these characters on land, they can be used as evidence of ancestry. Possible use of further characters is discussed. Copyright © Royal Society of Edinburgh 1989 isopods nationallicence land invasion nationallicence osmoregulation nationallicence prosobranch gastropods nationallicence talitrid amphipods nationallicence urine production nationallicence water balance nationallicence Transactions of the Royal Society of Edinburgh: Earth Sciences Royal Society of Edinburgh Scotland Foundation 80/3-4(1989), 201-208 0263-5933 80:3-4<201 1989 80 TRE https://doi.org/10.1017/S0263593300028649 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0263593300028649 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Little Colin Department of Zoology, Bristol University, Bristol BS8 1UG, U.K NATIONALLICENCE 773 0- Transactions of the Royal Society of Edinburgh: Earth Sciences Royal Society of Edinburgh Scotland Foundation 80/3-4(1989), 201-208 0263-5933 80:3-4<201 1989 80 TRE CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge