Growing to about a foot (30 centimeters) long, blind snakes act a lot like worms, burrowing under the surface of every continent except Antarctica. Unlike worms, though, blind snakes have backbones and tiny scales. "Continental drift had a huge impact on blind snake evolution by separating populations from each other as continents moved apart," said study co-leader Nicolas Vidal, of the Muséum National d'Histoire Naturelle in Paris. Now considered part of Africa, Madagascar split from what's now India about 94 million years ago. Since then, the blind snakes on Madagascar have changed enough to give rise to a whole new family, added Penn State biologist Blair Hedges, the study's other co-leader.
Blind Snakes Break Free of "Indigascar"
Blind snake fossils are nearly nonexistent, so their evolutionary history has been a mystery. But by comparing five genes from 96 far-flung blind snake species, the researchers were able to create a map of the snakes' evolutionary family tree. Using estimated time frames for genetic mutation, the team was able to estimate when the different species had arisen. The wormlike snakes first appeared on the southern supercontinent Gondwana, the team says.
As Gondwana split apart, the blind snakes were isolated to what the researchers call Indigascar—a landmass including what are now India and Madagascar. Relatively soon after the split, the newly recognized family arose, genetic data suggest.
Mystery of Blind Snakes' Spread
After the "Indigascar" split, blind snakes somehow migrated far beyond India and Madagascar. The snakes mysteriously appeared in Australia some 28 million years ago, for example—a period during which no land connections existed to that continent. And African and South American blind snake lineages apparently separated only 63 million years ago. That's some 40 million years after Africa and South America split up, so moving landmasses can't have caused the later evolutionary divide.
Initially the primary method of breeding Giant Pandas in captivity was by artificial insemination, as they seemed to lose their interest in mating once they were captured. This led some scientists to try extreme methods such as showing them videos of giant Pandas mating and giving the males Viagra. Only recently have researchers started having success with captive breeding programs, and they have now determined that Giant Pandas have comparable breeding to some populations of the American Black Bear, a thriving bear family. The current reproductive rate is considered one young every two years. Giant Pandas reach sexual maturity between the ages of four and eight, and may be reproductive until age 20. The mating season is between March and May, when a female goes into her estrous cycle which lasts for two or three days and only occurs once a year. When mating, the female is in a crouching, head-down position as the male mounts her from behind. Copulation time is short, ranging from thirty seconds to five minutes, but the male may mount her repeatedly to ensure successful fertilization. The gestation period ranges from 95 to 160 days. Cubs weigh only 90 to 130 grams (3.2 to 4.6 ounces), which is about 1/900 of the mother's weight. Usually, the female gives birth to one or two cubs. Since cubs are born very small and helpless, they need the mother's undivided attention, so she is able to care for only one of her cubs. She usually abandons one of her cubs, and it dies soon after birth. At this time, scientists do not know how the female chooses which cub to raise, and this is a topic of ongoing research. The father has no part in helping raise the cub.
Is it not the dream of a parrot owner to each one of his or her peers that they have a talking parrot? I know that was my goal. I always wanted to have a parrot that would greet every new guest that entered my house. It took a lot of training but in the end I finally achieved this goal and was able to tell everyone about it. What are some of the best things about having a talking parrot?The great thing about having a talking parrot is that you can teach them to answer every question you ask them with either a yes or no. How many other types of pets are there that can actually tell you if they have done something bad? After a great deal of practice a parrot can have the ability to understand every question it has been taught. Pretty amazing when you think about it.
t — and pick up fishing tips for his bear pal.