Question

Crews et al Behavior whiptail lizard

1. In the whiptail lizards the female will not undergo normal ovarian growth in the absence of sexual active males. How do parthenogenetic female whiptails get around this problem?

2. How did the species of parthenogenetic whiptails arise?

Answer 1

Define parthenogenesis:-

Parthenogenesis is an evolutionary adaption that allows female sexual reproduction to initiate without the need for males for stimulation or sperm. Females become unisexual and can reproduce on their own.

1) Although they are unisexual they reproductively active species exhibit pseudocopulatory behavior of their ancestors if they are housed together. The behavior of mating still facilitates sexual reproduction for the species’ breeding season.parthenogenetic whiptails exhibit behaviors seen commonly in sexually active male whiptails during mating. Since male-typical and female-typical sexual behaviors can refer only to those behavioral displays associated with males and females in gonochoristic species (e.g., intrornission and receptive behaviors, respectively).

2) The new research by Baumann and his team reveal that these lizards maintain genetic richness by starting the reproductive process with twice the number of chromosomes as their sexually reproducing cousins. These celibate species resulted from the hybridization of different sexual species, a process that instills the parthenogenetic lizards with a great amount of genetic diversity at the outset. And the researchers found that these species could maintain the diversity by never pairing their homologous chromosomes (as sexual species do by taking one set of chromosomes from each parent) but rather by combining their sister chromosomes instead. "Recombination between pairs of sister chromosomes maintains heterozygosity" throughout the chromosome,