 The most controversial model , known as viral eukaryogenesis , posits that the membrane @-@ bound nucleus , along with other eukaryotic features , originated from the infection of a prokaryote by a virus . The suggestion is based on similarities between eukaryotes and viruses such as linear DNA strands , mRNA capping , and tight binding to proteins ( analogizing histones to viral envelopes ) . One version of the proposal suggests that the nucleus evolved in concert with phagocytosis to form an early cellular " predator " . Another variant proposes that eukaryotes originated from early archaea infected by poxviruses , on the basis of observed similarity between the DNA polymerases in modern poxviruses and eukaryotes . It has been suggested that the unresolved question of the evolution of sex could be related to the viral eukaryogenesis hypothesis . 
 The most controversial model , known as viral eukaryogenesis , <a href='uninflect' title='1'><mark>posits</mark></a> that the membrane @-@ bound nucleus , along with other eukaryotic features , originated from the infection of a prokaryote by a virus . The suggestion is based on similarities between eukaryotes and viruses such as linear DNA strands , mRNA capping , and tight binding to proteins ( analogizing histones to viral envelopes ) . One version of the proposal <a href='uninflect' title='2'><mark>suggests</mark></a> that the nucleus evolved in concert with phagocytosis to form an early cellular " predator " . Another variant <a href='uninflect' title='3'><mark>proposes</mark></a> that eukaryotes originated from early archaea infected by poxviruses , on the basis of observed similarity between the DNA polymerases in modern poxviruses and eukaryotes . It <a href='been_done' title='4'><mark>has</mark></a> been suggested that the unresolved question of the evolution of sex could be related to the viral eukaryogenesis hypothesis . 
The most controversial model , known as viral eukaryogenesis , posit dat da membrane @-@ bound nucleus , along wit other eukaryotic features , originated from the infection of a prokaryote by a virus . Tdasuggestion is based on similarities between eukaryotes and viruses such as linear DNA strands , mRNA capping , and tight binding to proteins ( analogizing histones to viral envelopes ) . One version of the proposal suggest that the nucleus evolved in concert wwidphagocytosis to form an early cellular " predator " . anotha variant propose that eukaryotes originated from early archaea infected by poxviruses , on the basis of observed similarity between the DNA polymerases in modern poxviruses and eukaryotes . It done been suggested tdatthdanresolved question of thedaolution of sex could be related to the daal eukaryogenesis hypothesis .