Table 1

Lamarckian and quasi-Lamarckian phenomena

Phenomenon

Biological role/function

Phyletic spread

Lamarckian criteria

Genomic changes caused by environmental factor

Changes are specific to relevant genomic loci

Changes provide adaptation to the causative factor

Bona fide Lamarckian

CRISPR-Cas

Defense against viruses and other mobile elements

Archaea and bacteria (present in ~1/3 sequenced genomes)

Yes

Yes

Yes

piRNA

Defense against transposable elements in germline

Animals (apparently, all)

Yes

Yes

Yes

HGT (specific cases)

Adaptation to new environment, stress response, resistance

Archaea, bacteria, unicellular eukaryotes

Yes

Yes

Yes

Quasi-Lamarckian

HGT (general phenomenon)

Diverse innovations

Archaea, bacteria, unicellular eukaryotes

Yes

No

Yes/no

Stress-induced mutagenesis

Stress response/resistance/

adaptation to new conditions

Ubiquitous

Yes

No or partially

Yes (but general evolvability/

Adaptability enhanced as well)

Koonin and Wolf Biology Direct 2009 4:42   doi:10.1186/1745-6150-4-42