A male is defined as the gender that produces sperm or pollen: small, mobile, multitudinous gametes. A female produces few, large, immobile gametes called eggs. But size is not the only difference between male and female gametes. A much more significant difference is that there are a few genes that come only from the mother. In 1981 two scientists at Harvard whose perspicacity we will reencounter throughout the book, Leda Cosmides and John Tooby, pieced together the history of an even more ambitious genetic rebellion against this parliament of genes, one that forced the evolution of animals
A male is defined as the gender that produces sperm or pollen: small, mobile, multitudinous gametes. A female produces few, large, immobile gametes called eggs. But size is not the only difference between male and female gametes. A much more significant difference is that there are a few genes that come only from the mother. In 1981 two scientists at Harvard whose perspicacity we will reencounter throughout the book, Leda Cosmides and John Tooby, pieced together the history of an even more ambitious genetic rebellion against this parliament of genes, one that forced the evolution of animals and plants into strange new directions and resulted in the invention of two genders.21 So far I have treated all genes as similar in their pattern of inheritance. But this is not quite accurate. When a sperm fertilizes an egg, it donates just one thing to that egg: a bagful of genes called a nucleus. The rest of it stays outside the egg. A few of the father’s genes are left behind because they are not in the nucleus at all; they are in little structures called “organelles.” There are two main kinds of organelles, mitochondria, which use oxygen to extract energy from food, and chloroplasts (in plants), which use sunlight to make food from air and water. These organelles are almost certainly the descendants of bacteria that lived inside cells and were “domesticated” because their biochemical skills were of use to the host cells. Being descendants of free-living bacteria, they came with th...
...more
This highlight has been truncated due to consecutive passage length restrictions.
their own genes, and they still have many of these genes. Human mitochondria, for example, have thirty-seven genes of their own. To ask, “Why are there two genders?” is to ask, “Why are organelle genes inherited through the maternal line?”
