Haldane 's Rule : An Observation

Perhaps, where they coexisted, some difference prevented interbreeding or the production of hybrids between these populations and early human ancestors. Usually such differences between related species originate as adaptations to the environment, not as devices for reproductive isolation.

Lake Malawi’s cichlid male population of fish are tested on their ability to build bowers to attract the female population. Altering this extended phenotype, or ability to build bowers resulted in no change of mating, but males that built successful bowers showed to

The article that we read was called The Mystery of the Rare Male Sea Monkey by Nadia Drake. The rough idea of this article was how the female Sea Monkeys(brine shrimp) reproduced asexually and how the male Sea Monkeys couldn’t breed with their own kind. So, as a result, the male shrimp breed with different species resulting in hybrid offspring. It also compared shrimp that breed asexually and another that bred sexually. The vocabulary words found in the article were asexual, chromosome, and DNA. Asexual was used when explaining how the female sea monkeys reproduce. Chromosome was used when they explained that when an asexual lineage emerges, it gains an extra set of chromosomes. Finally, DNA was used when it said that for asexual

fitness does well in its habitat and passes those favorable alleles onto its offspring when it reproduces.

Apply your understanding of how alleles assort and combine during reproduction to evaluate a scenario involving a monohybrid cross.

Part B: Genes X, Y, and Z are linked. Crossover gametes between genes X and Y are observed

Judson contributes to onefs understanding of sex among different organisms in that she makes difficult concepts simple to comprehend. Although she uses scientific terminology, she limits it so that anyone can understand the technical information she shares. Judson also describes the types of environments in which each species and

Evidence supports that most likely, with male extinction comes primate extinction. This is because crucial maternal genes are sometimes activated through males on their Y- chromosomes (Marvan et al., 2005). But there is still a possibility, as the loss of the Y-chromosome after relocation of the SRY gene might prove successful for humans. However, evidence shows that when a Y-chromosome becomes functionless species are readily capable to adapt to male-less conditions (Marvan et al., 2005). Studies of the Y-chromosome have shown the importance of mapping out its evolutionary history in order to better understand why the Y-chromosome looks and functions the way it does. Its divergence outside of the monotremes showed that primates have ancestral Y- chromosome relationships with earlier mammals that independently evolved from other sex chromosome. Similarly, the variation of male specific genes, such as DAZ, display how significant the modification of the Y-chromosome truly can be. Its susceptibility to evolutionary pressures such as mutation, genetic drift, and natural selection. a The Y-chromosome’s potential for being preserved across lineages is relatively high. Although, some mutation can occur occasionally during

Research groups from the Imperial College of Science, Technology and Medicine and the Institute of Evolution at the University of Haifa have been studying the model organism, Sordaria fimicola, in regards to controlling cross over frequency in response to environmental pressures. Sordaria fimicola is a good model organism because it has a fast life cycle and elongated asci that are easily seen under a microscope. In addition, there are multiple different combinations of ascospore colors due to recombination during meiosis.

The prediction that the percentage of male gametophytes would increase as the population density of the gametophytes increased, and the prediction that the percentage of male gametophytes would decrease as the population density of the gametophytes increased were not supported by our results. When the population density was low, the percentage of male gametophytes was relatively low because there would not be enough eggs to fertilize the sperm produced from both the hermaphrodite,and the sperm produced by the male gametophyte. When the population density was high, the percentage of male gametophytes was higher but still less than fifty percent because of the same reasons.The data from our results did support our

11. The progeny of a Drosophila female (heterozygous at three loci: y, ct, and w) crossed to a wild type male are listed below:

For our first generation (F1) of flies we chose to cross apterous (+) females and white-eye (w) males. We predicted that the mutation would be sex linked recessive. So if the female was the sex with the mutation then all females would be wild type heterozygous. Heterozygous is a term used when the two genes for a trait are opposite. The males would all be white eye since they only have one X chromosome. If the males were the sex that had the mutation then all the flies would be wild type but the females would be heterozygous.

First to understand reproductive isolation you must know what speciation is meant to natural selection. Speciation occurs when natural selection dives one species to split into two or more species (Bethel University, 2015). When speciation occurs, it can leave a one of the groups in reproductive isolation which is the inability to mate. This can occur for a few different reasons there could be a barrier that creates divide or unique phenotypical traits that will not allow for the mating with another species. This essentially will lead to the extinction of the new species that is doomed to reproductive isolation

When two species are super similar such as the fire-bellied toad and the yellow-bellied toad they can mate and make a hybrid of the two species. Is this hybrid considered a new species or not? Overtime this question will be answered by reinforcement of the fact that they are different species, fusion which would mean that they become one species, or stability which means that yes hybrids exist, but it does not make any difference. However, in the moment the question is what to do with these new

The two alleles, one contributed by the male and the one by the female gamete remain distinct; alleles do not blend with one another or become altered in any other way