Search results
Results from the WOW.Com Content Network
In 1944, Reginald Ernest Moreau suggested that in more seasonal environments or higher latitudes, fecundity depends on high mortality. [11] David Lack suggested in 1954 that differential food availability and management across latitudes play a role in offspring and parental fitness. [12]
Less than 5% of breech babies have their heads in the "star-gazing" position, the face looking straight upwards and the back of the head resting against the back of the neck. Caesarean delivery is absolutely necessary because vaginal birth with the baby's head in this position confers a high risk of spinal cord trauma and death. [28]
The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged.The biomolecular data used for such calculations are usually nucleotide sequences for DNA, RNA, or amino acid sequences for proteins.
[21] [22] Babies who were fewer than 28 weeks of gestational age, or weighed fewer than 1000 grams, or fewer than 35 cm in length – even if they showed some sign of life (breathing, heartbeat, voluntary muscle movement) – were classified as "live fetuses" rather than "live births." Only if such newborns survived seven days (168 hours) were ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Survivorship curves can be constructed for a given cohort (a group of individuals of roughly the same age) based on a life table. There are three generalized types of survivorship curves: [ 1 ] Type I or convex curves are characterized by high age-specific survival probability in early and middle life, followed by a rapid decline in survival in ...
Locked twins is a rare complication of multiple pregnancy where two fetuses become interlocked during presentation before birth. It occurs in roughly 1 in 1,000 twin deliveries and 1 in 90,000 deliveries overall. [1]
“Early onset colorectal cancer (colon cancer in persons under age 50) is on the rise, but in absolute numbers, the risk is low. So there are a lot of people at risk, but very few will develop ...