Quotes About Biology

Women are nothing but machines for producing children." Napoleon Bonaparte ( Not me...

By growing a beard, a man turns his face into an echo of his crotch; and the capacity to grow a beard very likely predates the use of cosmetics by a few hundred thousand years.

mucus, a mixture of white blood cells, water, the sticky protein known as mucin, and cast-off tissue cells.

heavy bleeding in the premenopausal years is in fact normal.

estrogen spurs the growth of many cell types—mammal, insect, grain.

The body of the average woman is 27 percent fat, that of the average man 15 percent fat. The leanest elite female athletes may get their body fat down to 11 or 12 percent, but that is nearly double the percentage of body fat found on the elite male athlete

My daughter's eggs are silver points of potential energy, the light at the beginning of the tunnel, a near-life experience. Boys don't make sperm—their proud "seed"—until they reach puberty. But my daughter's sex cells, our seed, are already settled upon prenatally, the chromosomes sorted, the potsherds of her parents' histories packed into their little phospholipid baggies.

In a sense, evolution adheres to the classic twelve-step program: it takes things one day at a time. It does not strive for perfection; it does not strive at all. There is no progress, no plans, no scala natura , or scale of nature, that ranks organisms from lowly to superior, primitive to advanced.

For the record, the average penis is about 4 inches long when flaccid, 5.7 inches when erect. That's a bit bigger than the gorilla's 3-inch erection, but then there's the blue whale, the world's largest mammal, who has, yes, a 10-foot pole.)

humans have twenty-three pairs of chromosomes and that the pairs of chromosomes are the same in men and in women, with the exception of pair number 23—the sex chromosomes. In that case, women have two X chromosomes and men have one X and one Y. Moreover, a woman's two X chromosomes look pretty much like all her other chromosomes. Chromosomes resemble Xs.

In a female guinea pig, a membrane normally covers the vaginal opening. It takes the release of sex hormones during ovulation to open up the membrane and allow the guinea pig to have sex.

The attrition continues, though at a more sedate pace, throughout a woman's youth and early middle age. At most, 450 of her eggs will be solicited for ovulation, and far fewer than that if she spends a lot of time being pregnant and thus not ovulating.

Perhaps eggs are like neurons, which also are not replenished in adulthood: they know too much. Eggs must plan the party. Sperm need only to show up- wearing top hat and tails, of course.

the pinkish peritoneum, the springy membrane that encloses and protects other organs.

I don't want to make too much of androstenedione, though. Testosterone isn't the only hormone that's overrated. All hormones are ultimately overrated, as well as poorly understood. But even though we know this mantra, we still get shackled by testosterone and need a new perspective to shake ourselves free.

I had to admit he looked nice. He has very regular features and straight teeth. I'd just read that even, regular features are universally recognized as beautiful. So no matter what I think of Brooks as a person, I'm genetically programmed to find him attractive. I resent that.

Here is the most important thing to understand about cravings: They are not caused by weak will or gluttony. Cravings are triggered by biological properties of the foods themselves. That is, certain foods have chemical makeups that cause us to crave them in very much the same way that drugs, alcohol, and tobacco have addictive components.

We are all connected; To each other, biologically. To the earth, chemically. To the rest of the universe atomically.

The atoms of our bodies are traceable to stars that manufactured them in their cores and exploded these enriched ingredients across our galaxy, billions of years ago. For this reason, we are biologically connected to every other living thing in the world. We are chemically connected to all molecules on Earth. And we are atomically connected to all atoms in the universe. We are not figuratively, but literally stardust.

Evolutionary biologists now reckon that the six to seven billion people now living share the same small number of ancestors living two or three thousand years ago. These circumstances make nonsense of anybody's pretensions to find a pure racial ancestry.

Everything can't be explained by some general biological phrase.

Whereas cells in men have just a single, maternal X chromosome, cells in women have both a maternal and a paternal X chromosome. Female cells inactivate one of the two X chromosomes, resulting in a mosaic of cells with distinct combinations of gene variants. This variety could result in an immunity advantage compared to the more fixed expression in males.51

Can we treat animal behavior with the same medicines, therapies, and approaches we use on humans? To me, the answer is an obvious yes. You

The average human comprises forty trillion eukaryotic cells and an accompanying microbiome of a hundred trillion bacteria, mostly in the gut, and one quadrillion viruses. We are, in raw cell numbers, more microbe than mammal.