Each year in the United States, there are approximately six million pregnancies. This means that at any one time, about 4% of women in the United States are pregnant.
Did you know?
This year, an estimated 1.4 million Americans will have a new or recurrent heart attack.
Did you know?
There are 60,000 miles of blood vessels in every adult human.
Did you know?
About 3% of all pregnant women will give birth to twins, which is an increase in rate of nearly 60% since the early 1980s.
Did you know?
On average, someone in the United States has a stroke about every 40 seconds. This is about 795,000 people per year.
Difficulties in applying the morphological species concept
Species richness decreases with distance from the source pool.
Reconstructed Australopithecus afarensis spine shows that species walked upright.
DNA Among Species of Hominids
Invasive tumor: Tumor of the trachea invading and occluding airway.