Transposons and the dynamic genome
Transposons were instrumental in our evolution contributing to our fitness more then all other  traditional mutations. As transposons (TEs) emerge into our collective consciousness, they become more and more significant. They constitute 50% of our genome, and continually move around.

Hitherto we were told that genome is static and nearly frozen. Keeping its image from generation to generation.   New studies reveal a dynamic and vibrant genome.  When facing stress TEs are turning over, some are born others disrupted. All are dispersed by transposases.

I regard stress induced TE changes  and gene mutations are protective measures to keep a living entity alive. This newly acquired insight is inherited by its progeny.

 The most famous fusion protein is BCR-ABL, which was created in a CML stem cell stressed by a virus. Medicine states, that BCR-ABL is a random error mutation which causes leukemia.  I maintain that BCR-ABL  was created by TE activation to slow leukemia progression.   Without this protective protein, patient might have succumbed  to stress  like in acute leukemia.