Final answer:
Evidence supporting Dr. Malit's case for Neandertals and their co-existence with Denisovans includes nuclear DNA studies, the presence of Neanderthal and Denisovan DNA in modern humans, and mitochondrial DNA analysis. These genomic studies provide insights into interbreeding, common ancestry, and the evolutionary story of humans.
Step-by-step explanation:
Dr. Malit's case for the co-existence of Neanderthals and Denisovans, and their relationships with modern humans, relies on several types of genomic evidence. This evidence has helped to construct a story of human evolution that includes biodiversity within the genus Homo. Nuclear DNA studies have shown that Neanderthals and Denisovans were closely related to each other, yet distinct from modern humans. Additionally, the presence of Neanderthal and Denisovan DNA in modern human populations is compelling evidence of interbreeding between these species. For instance, mitochondrial DNA analyses revealed that Denisovans and Neanderthals shared a common ancestor, while other studies using the male Y chromosome, have suggested a replacement of the Denisovan Y chromosome in Neanderthals due to interbreeding with early humans.
Such genomic research has also provided insights into the possible competitive advantages that may have allowed modern humans to survive while Neanderthals went extinct. Genetic research has enabled modern humans to track their evolutionary story, understanding not only their lineage but also their interactions with other hominin species. This research continues to shape our understanding of human evolution and the complex web of interactions that existed between different hominin species over thousands of years.