Final answer:
The question relates to biology and involves understanding Ernst Haeckel's perspective on Neanderthals, a closely related human species that interbred with early modern humans, leaving a genetic mark on non-African populations. Studies have linked Neanderthal DNA to health issues and immune responses in modern humans.
Step-by-step explanation:
The question regarding Ernst Haeckel's reaction to Neanderthals is related to the field of biology, specifically human evolution and the study of ancient human species. It is known that Neanderthals are an extinct species within the genus Homo and are closely related to modern humans, having lived in Europe and parts of Asia until about 40,000 years ago. Discoveries in the field of genetics have shed light on the relationship between Neanderthals and modern humans, including findings of interbreeding and the sharing of certain traits and genetic markers. Genetic evidence shows that Neanderthal DNA makes up approximately 2 to 3 percent of the genome of people outside of Africa, indicating a complex history between the two species.
The Neanderthal genome has provided insights into diseases, immune responses, and adaptations that occurred as a result of interbreeding between Neanderthals and early modern humans. Indeed, studies have found links between Neanderthal genes and contemporary health issues such as diabetes, depression, allergies, and even responses to viruses like COVID-19. As modern human ancestors moved out of Africa, they encountered Neanderthals, resulting in genetic exchange before the divergence of different human populations around the world.
The debate about the fate of the Neanderthals includes various hypotheses, such as environmental changes, competition with Homo sapiens, spread of disease, or lower genetic diversity due to isolated and small populations. Current research continues to unravel the complex legacy of Neanderthals and their impact on modern human evolution.