A2.3.5 (HL)—Several origins of viruses Topic Practice
A2.3.5 (HL)—Several origins of viruses Topic Practice
Students practise evaluating competing hypotheses for viral origins—virus-first, escaped genes, regressive—using evidence of polyphyly and parasitism.
How this is tested
- distinguish virus-first from escaped-gene hypotheses using evidence of viral genome integration or lack
- explain how obligate parasitism in unrelated virus groups supports convergent evolution rather than shared