1995/01/01 by David Lazarus, Heinz Hilbrecht, Cinzia Spencer‐Cervato +1 · 2 citations
Earth and Planetary Sciences · Environmental Science · #Marine Biology and Ecology Research #Isotope Analysis in Ecology #Geology and Paleoclimatology Research #Sympatric speciation #Phyletic gradualism #Genetic algorithm #Glacial period #Paleontology #Geology #Population #Allopatric speciation #Ecology #Biology #Phylogenetics
paper · doi:10.1017/s0094837300013063
openalex publication_date 1995/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/26
Speciation processes are only rarely studied with fossil materials, even though in principle hypotheses of speciation patterns are most directly testable in the fossil record. We quantitatively document in two widely separated South Pacific DSDP holes the mid-Pliocene speciation of the planktonic foraminifer Globorotalia truncatulinoides. Speciation, with continuous geographic co-occurrence of ancestor and descendant forms, occurred simultaneously at both localities over a period of ~500,000 years. This suggests a sympatric speciation process that involved a large, geographically extensive population. Globorotalia truncatulinoides underwent its most rapid and extensive evolutionary change between ~2.8 and 2.5 Ma. This time interval corresponds to the development of northern hemisphere glaciation, suggesting that climate-controlled paleoceanographic change may have played a significant role in the evolution of G. truncatulinoides.