Tag Archives: Science

Just One Gene Determines the Queen Bee

From science blogs:

“A research team led by Wayne State University, in collaboration with Michigan State University, has identified a single gene in honeybees that separates the queens from the workers. The scientists unraveled the gene’s inner workings and published the results in the current issue of Biology Letters. The gene, which is responsible for leg and wing development, plays a crucial role in the evolution of bees’ ability to carry pollen. “The gene – Ultrabithorax, or Ubx – is responsible for making hind legs different from fore legs so they can carry pollen” said Aleksandar Popadic, associate professor of biological sciences in Wayne State University’s College of Liberal Arts and Science and principal investigator of the study. “In some groups, like crickets, Ubx is responsible for creating a ‘jumping’ hind leg. In others, such as bees, it makes a pollen basket – a ‘naked,’ bristle-free leg region that creates a space for packing pollen.””

Full post http://www.mdconnects.com/articles/305/20140131/research-led-wayne-state-discovers-single-gene-bees-separating-queens.htm

Why Are Sloths So Slow?

“For sloths, it’s one that works and is based primarily on metabolism and adapting to that change! Sloths are eating incredibly poor food. Plants do everything they possibly can to guard against being eaten, from tying up material in difficult to digest things like cellulose or lignin to producing compounds to actively reduce the efficiency of their digestion! Sloths have overcome many of these defenses by digesting food for extremely long times. By taking longer to digest the food and developing internal adaptations to do so, they can get energy out of a very abundant resource in the tropics; however, this comes at a price: they are limited in speed! Sloths move extremely slowly, so once they’re spotted, they’re easy game. Fortunately for the sloths, they’ve managed to develop forms of crypsis to avoid being seen! They can move so slowly that they are actually able to host algae and plant material in their fur, making them blend into their surroundings more easily. Moving slowly also draws less attention in general, so they can avoid being spotted that way.”

Unidan comments on Sloth crawling out of the water.

Humans are Altricial and Precocial

“When we discuss life history of animals, we discuss them as altricial or precocial. Altricial animals produce large number of offspring with a relatively small energetic investment in each one; therefore, the offspring are born pretty weak and many will probably die. Cats, mice, dogs – any animal that produces a litter is probably altricial. Other animals are precocial. That means a large energetic investment goes into each offspring; they usually reproduce one at a time and their offspring are born pretty ready to handle a lot on their own. Think of elephants, horses, whales, and so forth: long gestation periods, and offspring born capable of pretty full locomotion. Humans are the odd case. We are secondarily altricial. Our reproductive strategy looks like that of a precocial species – one progeny at a time and a substantial resource investment in each – but our infants resemble altricial infants much more than precocial ones.

Human life history only make sense if you look at human infants as fetuses that are continuing to develop outside the womb, and happen to have been born prematurely. In fact, up until it reaches eight months to a year of age, it is much more consistent with developmental understandings to see any baby as a prematurely born infant. Therefore, most of the development that you see in an infant is that which would “normally” take place in the womb. This is because, quite frankly, our large brain size prohibits birth at full brain weight. Most precocial mammals are born with brains fairly close to adult brain size; we do most brain development outside the womb that other precocial species do inside.”

Anthropologist on Reddit  comments on ‘If a child is born premature, do they develop as if they were still in the womb?

Image from http://www.ascensionearth2012.org/2013/12/neanderthal-viruses-found-in-modern.html