Soru

The following dual passages discuss horizontal gene transfer in evolutionary biology.

Passage A
For decades, the neo-Darwinian synthesis relied on a singular, elegant metaphor: the Tree of Life. In this paradigm, genetic material flows strictly vertically from parent to offspring, with speciation represented by continuously branching, divergent lineages. However, rapid advancements in genomic sequencing have revealed that horizontal gene transfer (HGT)—the lateral sharing of DNA across distinct species boundaries—is not merely a bacterial idiosyncrasy but a pervasive, driving force in eukaryotic evolution. The sheer volume of exogenous DNA found in complex organisms dictates that the Tree of Life is no longer a tenable conceptual model. When genes are routinely acquired from distant relatives, viruses, and even environmental interactions, the concept of a neatly branching, isolated lineage inherently breaks down. We must discard the arboreal metaphor entirely in favor of a "web" or "net" of life. This conceptual overhaul is biologically necessary because acknowledging that eukaryotic genomes are profound, interconnected mosaics fundamentally alters our understanding of evolutionary novelty. Adaptation in complex organisms is frequently driven not by the slow, gradual accumulation of vertical mutations, but by the rapid, disruptive assimilation of pre-tested genetic packages from entirely different branches of the biosphere. To pretend that a few horizontal lines on a traditional diagram can capture this complexity is to willfully ignore the reality of genomic fluidity. The architectural foundation of modern evolutionary biology must be rebuilt from the ground up to center lateral assimilation.

Passage B
The recent deluge of genomic data has undoubtedly complicated our traditional understanding of evolutionary history. The discovery that horizontal gene transfer (HGT) occurs in multicellular eukaryotes—providing them with crucial adaptive traits, such as novel metabolic enzymes or pest resistance—has rightfully challenged the strict verticality of the classical evolutionary tree. Some researchers now argue this necessitates abandoning the tree metaphor altogether in favor of network-based models. Such a radical discarding, however, is premature and ultimately counterproductive to the study of biology. While it is undeniably true that the classic neo-Darwinian model failed to predict the extent to which eukaryotic genomes incorporate foreign DNA, vertical descent with modification remains the overwhelmingly dominant mechanism of inheritance for the vast majority of traits in complex, multicellular organisms. HGT events, though evolutionarily significant when they occasionally confer a massive selective advantage, represent a comparatively small fraction of the overall genetic architecture in most eukaryotes. Therefore, the Tree of Life remains an indispensable scaffolding for mapping macroscopic diversity. We should certainly update our models to reflect the reality that genetic material can occasionally cross lineage boundaries, perhaps by drawing lateral connecting vines between the robust branches of our phylogenetic trees. However, recognizing the existence of these lateral transfers does not negate the fundamental utility of tracing the primary, vertical pathways of evolutionary descent. Abandoning the tree framework would plunge comparative genomics into chaos, removing the very baseline required to identify when horizontal transfers have actually occurred. The tree provides the necessary context; without it, the web becomes an unreadable tangle.

Which one of the following statements most accurately expresses a view shared by the authors of both passages regarding horizontal gene transfer and evolutionary frameworks?