Outbreeding depression in the common frog, Rana temporaria

• Theory suggests that parental relatedness is a continuous variable with a fitness optimum that we heretoforth will refer to as 'optimal outbreeding. In the present paper, we test this proposition from a conservation (translocation) perspective. Amphibians are facing a global decline and many amphibian populations are today small and threatened by extinction. Because genetic differentiation is often high between amphibian populations, they could be particularly sensitive to outbreeding depression, e.g. due to breakdown of locally adapted gene complexes. We tested if outbreeding would reduce fitness in common frogs, Rana temporaria, crossed from a large and an isolated, small population, separated by 130 km, using artificial fertilization. For females from the large population, tadpoles were significantly smaller and more malformed in crosses with males from the small population, than with males from the large population. For the small population, however, no significant paternal genetic effects could be found. The difference in response to outbreeding between populations was accompanied with significant differences in the importance of maternal effects. We conclude that care should be taken when translocating frogs between distantly related populations to avoid outbreeding depression.

Ämnesord

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Nyckelord

amphibian decline

inbreeding

outbreeding

rana temporaria

population divergence

genetic-structure

bufo-bufo

conservation

dispersal

selection

translocation

amphibians

heterosis

sylvatica

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)