Final answer:
Unequal crossing over can cause genetic disorders due to chromosomal abnormalities, such as duplications or deletions, potentially resulting in conditions like Down syndrome or Turner syndrome and affecting an individual's fitness.
Step-by-step explanation:
The clinical implications of unequal crossing over during meiosis are significant as it can lead to genetic disorders. Crossing over typically occurs between homologous non-sister chromatids, allowing for a reciprocal exchange of DNA and contributing to genetic variation. However, when the process is not precise, it may result in duplications, deletions, or more complex chromosomal rearrangements, which can manifest as various medical conditions or developmental abnormalities. Unequal crossing over can specifically cause disorders such as aneuploidy, where cells have an abnormal number of chromosomes, potentially leading to conditions like Down syndrome (trisomy of chromosome 21) or Turner syndrome (monosomy X). As these changes can impact a broad range of developmental processes, individuals with such mutations might be considered less fit compared to other members of their species.