Editing Common descent (section)

===Convergent evolution===
{{further|Convergent evolution}}

If early organisms had been driven by the same environmental conditions to [[Convergent evolution|evolve similar biochemistry convergently]], they might independently have acquired similar genetic sequences. Theobald's "formal test" was accordingly criticised by Takahiro Yonezawa and colleagues<ref>{{cite journal |last1=Yonezawa |first1=Takahiro |last2=Hasegawa |first2=Masami |title=Was the universal common ancestry proved? |date=16 December 2010 |journal=Nature |volume=468 |issue=7326 |page=E9 |doi=10.1038/nature09482 |pmid=21164432|bibcode=2010Natur.468E...9Y |s2cid=4318346 |doi-access=free }}</ref> for not including consideration of convergence. They argued that Theobald's test was insufficient to distinguish between the competing hypotheses. Theobald has defended his method against this claim, arguing that his tests distinguish between phylogenetic structure and mere sequence similarity. Therefore, Theobald argued, his results show that "real universally [[Conserved sequence|conserved]] proteins are [[sequence homology|homologous]]."<ref>{{cite journal |last=Theobald |first=Douglas L. |date=16 December 2010 |title=Theobald reply |journal=Nature |volume=468 |issue=7326 |page=E10 |doi=10.1038/nature09483|bibcode=2010Natur.468E..10T |s2cid=4317014 |doi-access=free }}</ref><ref>{{cite journal |last=Theobald |first=Douglas L. |date=24 November 2011 |title=On universal common ancestry, sequence similarity, and phylogenetic structure: The sins of P-values and the virtues of Bayesian evidence |journal=Biology Direct |volume=6 |issue=1 |page=60 |doi=10.1186/1745-6150-6-60 |pmc=3314578 |pmid=22114984 |doi-access=free }}</ref>