I read a captivating book,infact quite unusual one that gives me a sense of exhilaration.The book is Power,Sex and Suicide ,Mitochondria and the meaning of life by NICK LANE.The author provides breathtaking facts to establish that Mitochondria are the Clandestine rulers of the world.
Well,textbooks of the biology mention that mitochondria are power houses,a familiar word for any biology student.Few books dwell on its role in cell death . The book celebrates mitochondria for its role in our life,from rise to fall.
It is wonderful to note that mitochondria make the complexity possible in higher organisms,it governs and exceutes the power laws of biology,fulcrum for the two sexes,and a benovolent dictator, it kills us in the end.
Coming to the title,Why are they two sexes?
Some excerpts from the book.
The advantage of the sex lies in the recombination of DNA from distinct sources.which may help to eliminate broken genes and to foster variety.Hence the need for two parents.
What's wrong with having only one sex to do this,which amounts to having no sexes at all ?
Sperm are tiny and disposable.Men and males in general produce them by bucket load.Females produce far fewer,much larger eggs. needless to say,the eggs are immobile and sperms are motile. Why is it so?
Females invest more of their resources in the offspring,biologically.fertilised egg provides not just the genes,also all the nutrients and cytoplasm for the organism to grow.Sperm add next to nothing,except their genes.They behave like parasites.
Choroplasts and mitochondria are invariably inherited only from one parent,mother.It is the female who contributes to cytoplasm of the offspring. This is because mixing the cytoplasm from two different cytoplasmic genomes creates a conflict among cytoplasmic genomes.
The mitochondria exhibits selfish behaviour.They help safeguard their own transmission in the egg by eliminating males in hermaprodites.All through the evolution numerous tricks have evolved to exclude male mitochondria altogether
For those of you interested in some of the profound questions of science,this book is a must read.