To our knowledge, an algal felt from a penguin rookery in Antarctica displayed the highest autotrophic δ 15N value (approximately +31‰), which was attributed to the evaporation of ammonia from the soil, whereas the lowest value (−49‰) was observed in algae collected from a pond in the Dry Valley area in Antarctica (Wada et al. 1981).
They can also be observed in algae and cyanobacteria, suggesting that these are adaptations to the conditions prevailing in Antarctica.
Similar links between amino- and fatty acid metabolism have previously been observed in other algae, such as Chlamydomonas reinhardtii[ 39].
Rapid evolution has been observed in green algae as well as some diatoms and dinoflagellates (see Table 1).
These results are intriguing because they hint at the existence (present or in the recent past) of sexual reproduction in the Cyanidiales, a process that has never been observed in these algae either in culture or in the wild.
In the recent genome-wide assessment of rDNA organisation in land plants done by Wicke et al. (2011), it was concluded that a linked 35S 5S rDNA (L-type arrangement) should be regarded as the ancestral state as this type has been observed in streptophyte algae and early diverging green plants such as liverworts, mosses, hornworts, lycophytes and monilophytes.
Rare insertions of retrotransposon elements into the plastid genome have been observed in the alga Chlamydomonas reinhardtii[ 66], but based on our knowledge this is the first evidence of transfer of DNA from mitochondrial genome to plastid genome, and the potential presence of a possible retrotransposon in the plastid genome of a flowering plant.
High amounts of potential energy sinks like starch, lipids and secondary carotenoids have been observed in psychrophilic green algae (Leya et al., 2009; Remias et al., 2009).
Bioconcentration, bioaccumulation and biomagnification of antimicrobials have been observed in multiple organisms, including algae, aquatic blackworms, fish, and even dolphins, whereas affected terrestrial organisms include earth worms and higher species up the food chain.
The reversal of the ciliary-type beating of the flagella shown in this study has not yet been observed in other plants or green algae, but it has been reported for ciliates [ 76, 77] and some metazoa [ 78, 79].
