Got to admit, I thought this was about eugenics and culture.
In vitro fertilization (IVF) accounts for up to five percent of babies born in developed countries, and the technique has yielded some five million people ever since Louise Brown was born in the UK on July 25, 1978. And that’s just humans; the technology has been a huge boon in breeding farm animals. Yet there are hints that the procedure can have some unwanted effects on the resultant embryos. One such indication is a skewed sex ratio.
Looks like the fix is just a change in culture medium. It will take some time for this to become mainstream for human IVF. It also looks like (from the abstract) that this extra bath doesn’t harm male embryos in any way, so it won’t require genetic testing of embryos to sort out the girls (extra $$$ and mandatory freeze).
The best part is that this fix will likely increase overall success rates as those female embryos that would have failed instead thrive. Even a small % increase in success means so much to people desperately trying for a child, regardless of gender.
For centuries, humans have been curious about the effect that birth order has on personality, possibly because eldest children in ruling families typically inherited the seat of power. A new study published in PNAS finds that firstborn children tend to score higher on objective measures of intelligence and self-reported measures of intelligence. But it finds that there are no birth-order effects on other personality characteristics.
Older by minutes or even seconds, makes no difference… 😉
Pregnancy and birthing are very taxing on women, I’ve read studies that claim a woman’s body does not return to normal for 4-5 years after a pregnancy. I wonder if there is some correlation between the intelligence gap and the age difference of the siblings. Would not surprise me to find that pregnancies that happen before the body has fully recovered means that the woman’s body cannot give as many resources to the subsequent children during those critical developmental stages.
TLDR: Got older siblings? If so, here’s something shiny to play with. …but you missed the squirrel.
The human hand is remarkably different from that of other primates, with shorter fingers, a smaller palm and a significantly stronger thumb; of course, the most notable feature of our hands is the ability of the thumb to perfectly and comfortably oppose (come into square contact at the tips) each finger of the same hand. While we can’t know with 100% certainty all the factors that led to the evolution of our hands, it would seem it all revolves around this perfect opposability, and the various advantages that provides in certain scenarios, that has dictated the length of each finger.
On a related note, sickle-cell anemia is an example of evolution. It makes you completely immune to malaria (which kills children before they can become adults) in exchange for having a natural lifespan of 25-30 years (long enough to reproduce).
Yes, yes, you can tell me all about why I definitely shouldn’t be eating those mashed potatoes in a moment. But right now, I’ve got some news for you (and some potatoes to eat).
A new study in September’s Quarterly Review of Biology attempts to do some forensic reconstruction of ancient human diets using an interesting method: looking at physiological changes and the nutrition that would have been necessary to support them. Of particular interest to the researchers were a pair of salivary amylase genes that began to rise a million years or so ago, along with the rise of cooking.
What always bugged me about ‘paleo’… ancient humans ate whatever was handy. If grains and tubers were nearby, that’s what people ate. The diet of someone in the tundra is vastly different from someone in Polynesia, whose diet was different from someone in the rain forest.
How much of a dose of radiation do you get by snuggling up against your significant other for a year? Unless they’re glowing green, it’s a small dose, but it’s not nothing. We’ll tell you how much radiation you, and the people around you, emit.