A review of genetic analyses of hybridisation in New Zealand

Abstract

Hybridisation between related taxa has a range of possible biological consequences, ranging from the production of sterile offspring, through introgression of alleles into populations, to the formation of new species. Examples of plant and animal species hybridising with related taxa abound in the New Zealand region. We review New Zealand examples of hybridisation that have been verified with chromosomal, protein or DNA data. Contemporary hybridisation has been studied at hybrid zones where distinct populations meet and mate in a defined and stable zone of contact. The role of human habitat modification is highlighted with examples of recent range changes that have led to hybridisation and subsequent conservation problems. Hybridisation can result in the swamping of endangered species, although it can also act as a bridge for the transfer of adaptations among lineages. Historical hybridisation in New Zealand has been examined with phylogenetics and there are many examples of organelle introgression or capture. The origin of new species of New Zealand stick insects, ferns and daisies via hybridisation has been demonstrated with cytogenetic and DNA sequence evidence. Thus the importance of hybridisation in the evolution of New Zealand's flora and fauna is highlighted.

Keywords:

• conservation
• gene flow
• hybrid
• introgression
• New Zealand
• polyploidy
• speciation

Notes

Ecology Group/AWCMEE, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand.

Landcare Research, PO Box 40, Lincoln 7640, New Zealand.

MuseumofNewZealand Te Papa Tongarewa, PO Box 467, Wellington 6140, New Zealand/AWCMEE, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand.

Department of Zoology, University of Otago, PO Box 56, Dunedin 9054, New Zealand.

Bioinformatics Institute, School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland Mail Centre, Auckland 1142, New Zealand.

Institute for Molecular Systematics, School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand.

School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.