2) Experimental evolutionary biology

We use a powerful tool to inquire how nature solves fundamental biological questions: We simply let traits evolve in the laboratory under different environments, or of different genetic make-ups. Currently, we are focussing on how sperm parameters evolve under low oxygen and under high CO2. We also aim to look how the insect immune system evolves under these conditions.

2.1. Animal Behaviour and evolution: How much, and how rapidly, do reproductive traits evolve? Why is reproduction so complicated?

bugs matingReproductive traits of males can be harmful to females. Females can adapt to males upon which males evolve more harmful traits, leading to stronger, or novel, female traits and so on. This fast ping-pong play of coevolution results in a complicated network of sexual interactions. In bedbugs, during sex (upper picture) males force a copulatory knife (lower picture) into the female body (traumatic insemination) – females evolved a biomaterial that reduces the damage. Males transmit bacteria during mating – females evolved a novel immune organ. Males mate when females are unable to resist matinbedbug_penisg – females respond by situation exploitation – come and find out what that is. Pictures left: Bedbugs matings – no romance involved (top). The male copulatory dagger (below). Populations can evolve into new species (speciation) via sexual conflict, if females evolved traits that defend them only against males of their own, but not against males of a foreign population. However, different female genotypes may also respond to male harming in different ways (polymorphism). The prime example of such polymorphism is the genitalia mimicry in an African batbug in which males inseminate other males.

Further reading:

SEX HURTS – Our paper showing that traumatic insemination is widespread among animals, and has diverse forms and functions

SEX MAKES FEMALES YOUTHFUL – The seminal fluid of bedbugs makes female lay more eggs and toget old later, rather than earlier. A fountain of youth. Paper here.

MALES FORCE DEFENSELESS FEMALES TO SEX – see our paper on a new concept in animal behaviour

FEMALES MIMIC MALES THAT MIMIC FEMALE – Huh??? And all of this in genitalia… supports a theoretical model in sexual conflict.

SEXUAL CONFLICT SELECTS FOR A NOVEL ORGAN – Microbes transmitted during enforced sex in bedbugs leads to the evolution of a unique, novel immune organ. Paper here.

SEX REALLY HURTS – our new book chapter on copulatory wounding in animals and humans.

2.2. How much does the communication between mitochondria and the nucleus shape the offspring phenotype?

Mitochondria substantially influence the phenotype, that’s well known. What is less well known is how much the joint inheritance of (half) the maternal genome and the mitochondrial genome leads to evolutionary changes.

Further reading:

A LOT OF INFLUENCE ON THE PHENOTYPE and with substantial medical consequences for the Mitochondrial Replacement Therapy, as two of our papers show: one in Science, one in EMBO Reports

2.3. Other projects

– In collaboration with Jessica Abbott, Univ Lund, we are studying a range of fully sequenced Drosophila lines and ask how these different genomes respond to the same environmental manipulation.

INBRED – our new paper on inbreeding effects