Where did mitochondria come from?

Mitochondria, the powerhouses of the human cell, are passed to offspring only from the mother. Dad's mitochondria are used to propel those sperm toward the egg. Mitochondria have their own DNA, and their own system of replication and translation; they reproduce by simple binary fission. Sort of like a bacterium. That's why Lynn Margulis, in 1970, proposed that they--and chloroplasts--were independent organisms that genetically modified existing cells by taking up permanent residence in their hosts.

Click on Read more to see what they look like.

This photo was so beautiful, I couldn't pass it up. I took if from another source, which has not been updated since 2002. Don't know where it came from before that.

What a wonderful addition for multicellular organisms! Mitochondria made energy production so much more efficient by using starches and carbohydrates to produce energy and O2 and chloroplasts made it possible for cells to capture CO2 and produce starch and O2. I wonder which organelle came first?

Anyway, here's a salute to mitochondria and chloroplasts and successful genetic modification.

Marie Godfrey, PhD