Mammals shrink faster than they grow - Technology & Science. An international team of scientists, including some from Canada, has discovered that mammals shrink at faster rates than they grow — a finding that sheds light on the conditions that potentially contribute to extinction.
Their study, published Monday in the Proceedings of the National Academy of Sciences, shows it took about 24 million generations for a mouse-sized animal to evolve to the size of an elephant, but only 100,000 generations for very large decreases leading to dwarfism to occur. The research is unique because previous work in this area has focused on microevolution — the small changes that occur within a species. The paper studied 28 different types of mammals from the four largest continents (Africa, Eurasia, and North and South America) and all ocean basins for the last 70 million years. For example, one group would include the mammals related to an elephant, another group would include carnivorous mammals. Jessica Theodor is holding an elephant’s femur bone. The Talk.Origins Archive: Evolution FAQs. It Takes 24 Million Generations For a Mouse To Evolve Into an Elephant. 50-Legged Creature May Have Been Top Predator Of Ancient Seafloor.
An artist's rendering of a Tegopelte, a foot-long arthropod that lived 500 million years ago.Marianne Collins An ancient cockroach-like creature nearly a foot long once skittered along the seafloor in what is now Canada, a new fossil find reveals.
The fossil, a series of 500-million-year-old tracks, captured the movement of a large seafloor-dwelling creature with at least 25 pairs of legs. The animal was likely an arthropod called Tegopelte, a rare giant very rarely found fossilized. Arthropods are invertebrates with exoskeletons, a group that includes today's crustaceans and insects. Reporting the discovery Tuesday (Nov. 8) in the journal Proceedings of the Royal Society B, researchers led by Nicholas Minter of the University of Saskatchewan in Canada suggest that Tegopelte was a fearsome predator or perhaps a quick-moving scavenger, capable of "rapidly skimming across the seafloor" with only a few of its many legs touching the ground at a time.
Evolution. Most Beautiful Dinosaur Park. July 16th, 2011 Toxido In this time most of little kids don’t know about dinosaur because they are not still alive but our 3d and historical Hollywood films give a good view on dino life and therefore kids know very well.
In old age dinosaur is most biggest animals on the earth and dinosaur also have different species some dinosaur is like to eat vegetable and some dinosaur love to eat others small animals or small dinosaurs some time one big dinosaur is killed another big dinosaur but its so rare. Today I get to you in dinosar park but dont worry these are just sculptures and well painted. Therefore dinosaurs looks real and horoor too. You can leave a response, or trackback from your own site. Evolushark. How did life originate? How did life originate?
Living things (even ancient organisms like bacteria) are enormously complex. However, all this complexity did not leap fully-formed from the primordial soup. Instead life almost certainly originated in a series of small steps, each building upon the complexity that evolved previously: Simple organic molecules were formed. Simple organic molecules, similar to the nucleotide shown below, are the building blocks of life and must have been involved in its origin. Multicellularity evolved. Survival of the Sneakiest. How It Works. Artificial selection in the lab. Artificial selection in the lab For thousands of years, humans have been influencing evolution, through changes we have caused in the environment — and through artificial selection in the domestication of plants and animals.
In many cases, scientists have carefully documented evolution through artificial selection in the lab. John Endler performed experiments in microevolution, allowing artificial selection to manipulate the spots on guppies. Guppy spots are largely genetically controlled. Spots that help the guppy blend in with its surroundings protect it from predation — but spots that make it stand out help it attract mates. After fewer than 15 generations of selection, the markings of guppies in different ponds had substantially diverged as a result of natural selection. Endler then performed another experiment, with the same pond set-ups but without predators. Top-10-evolution-myths.pdf (application/pdf Object)