The effect of vicariance and dispersal on the evolution of ratites. Introduction The ratites are an interesting clade within Aves, and one that caused problems for biologists and biogeographers for many years. This is a group of large, flightless birds that are distributed across all of the southern continents, separated from each other by thousands of miles of oceans. How do species incapable of dispersing across these geographic barriers display such a pattern? It wasn’t until Alfred Wegener (1912) presented his theory of continental drift that a reasonable explanation was available.
Diet The main food that Koalas eat is eucalyptus leaves. Eucalyptus leaves are very fibrous and low in nutrition. Eucalyptus leaves contain a lot of water so koalas don’t have to drink. The koala’s metabolism rate is also regulated in a way to complement the heat insulation of the fur. The metabolism of the koala is quite slow it is only 74% of other animals’ metabolism rate.
He discovered that the individuals who can survive long enough to procreate did so because of specific traits that had made them stronger and more able to survive than the ones that died off. This is known as “survival of the fittest.” Over time, the strong traits get passed down from generation to generation and the weak traits slowly disappear. Biology has shown that there are certain traits that get passed down genetically, for example, the Galapagos finches’ beak shape. The Galapagos finches developed different beak shapes depending on the type of food that was available in their environment. There was one group of finches that had narrow beaks for picking up seeds and insects, and another group that had shorter, stronger beaks for cracking nuts.
We all know about Charles Darwin and his theory of evolution by natural selection, so eloquently expressed in his “Origin of Species”, published in 1859. Darwin rightly postulated that humans evolved in Africa, and that a “missing link” remained to be discovered. Several“missing links” have been found in Africa, among them in the 1950s “Zinj”(Zinjanthropus), and “Handy Man”(Homo habilis), both discovered in Olduvai Gorge, Kenya by Louis Leakey, as well as “Lucy” (Australopithecus afarensis) discovered by Don Johansen in Ethiopia in 1974, to “Turkana Boy”(Homo erectus), discovered by Richard Leakey in Kenya in the 1980s. Each in its own time had been hailed as “the missing link”, and as our direct ancestor. Many discoveries have been made since, and the ‘family tree’ has proved to be quite ‘bushy’, as it were.
Howler Monkey I want to introduce you to the howler monkeys. Howler monkeys don’t need a loud speaker to talk. These boisterous primates eat leaves from the canopy of the forest along with fruits, nuts, and flowers. They live in tropical central and South America and also they live in small groups of about 12 individuals. They have a short snout, and wide-set, round nostrils and grow to be about 2 feet in length, not including their 30-inch tail.
Even though it is a popular animal doesn’t mean we all know the history of this exotic animal. The zebra is just like a human with its distinct stripes like how we have our distinct finger prints. Their main homeland is in Africa in the plains. They live in herds of small family groups all their lives. The males once they reach their highest maturity level will leave their original family group and will go find another one.
This battery allows consumers to mow their lawns more frequently without having to recharge the battery too often. Toro’s innovation allowed the company to develop a new product that is different from the lawnmowers in the current market. Product positioning is a marketing technique intended to present products in the best possible light to different target audiences (Inc., 2013). Toro’s three product positioning strategies against their competitors are consumer convenience, consumer values, and consumer health. Scout is convenient to consumers because it allows the consumer freedom of time, reduces frustration from heat, and limits the continual purchase of gasoline.
Big Foot Needs Big Home Les Schobert, the author of the article “Let the Zoo’s Elephants Go” spent more than thirty years taking care of elephants as a curator. After years living with wild animals, he started writing about the elements in Nation Zoo and the things that were happening to them. “Let the Zoo’s Elephants Go” was published on October 16, 2005 as an urgent call to Nation Zoo for freedom for elephants. In the article “Let the Zoo’s Elephants Go”, Schobert debated that Zoos must change the concept about keeping elephants in a small captivity and send them to a bigger place like sanctuary. Since elephants are big animals, they need to live in a lot bigger space, but the zoos only provide them small areas to live, so they can easily get harm, especially in their feet.
If we find the bones of hippopotamus or zebra in the desert it is obvious that this territory was savanna with lakes and rivers before. In this way scientists defined that 7 million years ago the habitat of our ancestors - Africa was a mosaic of different environmental areas. Tropical forests started to recede, giving place to the grasslands. As the environment in which our ancestors lived was changing, they had to
When the desiccation of the Sahara began in 5000 B.C.E., the peoples of the Sahara were forced to move somewhere habitable, and they migrated eastward toward the Nile valley. “Guns, Germs, and Steel” shows also how the changing climate affected development. The peoples in the region of the Black Sea had land they used to farm, but it eventually became unserviceable. They gradually moved into central Europe or Asia. Interaction and exchange in Africa also played a major role in development.