Text 1
For years, genomic research supported the hypothesis that modern dogs () were domesticated from a single, now-extinct wolf population in Western Eurasia between and years ago. Proponents of this single-origin model point to shared genetic markers across diverse ancient canine remains, arguing that the complex behavioral adaptations required for domestication—such as reduced fear of humans and altered dietary tolerance—were so evolutionary improbable that they likely occurred only once. From this perspective, any genetic similarities found in eastern wolf populations are merely the result of subsequent migrations and interbreeding, rather than independent domestication events.
Text 2
Conversely, a study analyzing ancient genomes suggests a dual-ancestry model, showing that early dogs in eastern Eurasia and western Eurasia were genetically distinct. The researchers propose that wolves may have been domesticated independently by two separate human communities in these geographically isolated regions. While some biologists argue that this dual-origin theory overcomplicates canine evolutionary history, the distinct genetic profiles of early Siberian and European dogs suggest that human-wolf self-domestication pathways were not singular anomalies, but rather replicable ecological interactions that occurred when human settlements expanded.
Based on the texts, how would the author of Text 1 most likely characterize the dual-ancestry model discussed in Text 2?
- AAs a convincing framework that successfully reconciles the genetic discrepancies between western and eastern ancient canine remains.
- BAs a flawed hypothesis that erroneously claims Siberian and European wolves were genetically identical before domestication.
- As an implausible explanation that underestimates the evolutionary rarity of the behavioral and physiological changes required for domestication.Answer
- DAs a redundant theory that merely restates the well-established timeline of ancient human migrations.