Table 1.
Examples of natural (A) and experimental (B) chimeras across 12 obligately multicellular taxa.
Table 2.
Examples of natural (A) and experimental (B) chimerism in 18 mammalian species.
Fig 1.
Phylogenetic tree of the highest level of chimerism observed and the highest level of tumour invasiveness observed in each of 12 obligately multicellular taxa across the tree of life.
Red bars show the highest level of tumour invasiveness observed in each taxon, from low to high tumour invasiveness (no cancer observed, cancer/cancer-like phenomena, cancer, transmissible cancer). Black bars show the highest chimerism level observed in each taxon, from low to high chimerism (no chimerism observed, accepts cells from a close relative e.g., mother or twin, accepts cells from the same species other than a close relative, accepts cells from different species). The phylogenetic tree was created using the Time Tree of Life (http://timetree.org/). Images show example species in each taxon (images from http://phylopic.org/). The time bar shows millions of years (MY).
Fig 2.
The highest level of tumour invasiveness observed is positively correlated with the highest level of chimerism observed across 12 obligately multicellular taxa on the tree of life (PGLS analysis: * P-value < 0.05).
We show each taxon with a flask, a globe, or both, according to whether it consists of experimental chimeras (flask), natural chimeras (globe), or both. We use minimal jitter to better visualise individual taxa.
Fig 3.
Phylogenetic tree of malignancy, neoplasia prevalence, and the highest levels of chimerism observed in 12 terrestrial mammalian species.
Red shows the malignancy prevalence of each species. Pink shows the benign neoplasm prevalence of each species. Red together with pink show total neoplasia prevalence. In the case of adult humans, we only show their malignancy prevalence from https://ourworldindata.org, as we do not have data on their benign neoplasm prevalence. Black bars show the highest chimerism level observed in each species, from low to high chimerism (no chimerism observed, accepts cells from a close relative e.g., mother or twin, accepts cells from the same species other than close a relative, accepts cells from different species). The phylogenetic tree was created using the Time Tree of Life (http://timetree.org/). We obtained images of species from http://phylopic.org/. Time bar shows millions of years (MY).