Estimation of cell size and DNA content in fossil fishes and amphibians

✍ Scribed by Thomson, Keith Stewart ;Muraszko, Karin

• Book ID: 102337094
• Publisher: John Wiley and Sons
• Year: 1978
• Tongue: English
• Weight: 269 KB
• Volume: 205
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402050216

✦ Synopsis

Abstract

Genome size (cellular DNA contents) in living and fossil amphibians and their ancestors among the fossil lobe‐finned fishes are estimated indirectly through measurement of cell size, following procedures previously established in a study of evolutionary changes in the genome size of lungfishes. It is concluded that large DNA contents per cell arose several times independently within the Amphibia; that the ancestral lobe‐finned fishes and the early amphibians and reptiles all had small cell size and low DNA contents (5 –10 pg/nucleus). There is no evidence that an increase in genome size is a causal factor in major evolutionary change, rather it occurs in the end members of lineages.