Cladistics is the hierarchical classification of species based on evolutionary ancestry. It’s distinct from other taxonomic classification systems because it focuses on evolution rather than similarities between species. This is because it places heavy emphasis on objective and quantitative analysis. Cladistics generates diagrams called cladograms that represent the evolutionary tree of life. The starting point of cladistic analysis is a …

These affect the fingers and toes when they get very cold in winter. An inflammation sets in and produces red swellings that can hurt and/or itch once the coldness wears off.

When the huge plates that cover the Earth move, they create enormous tension that cracks rocks, forming long faults. Blocks of land pushed up between roughly parallel sets of faults form block mountains. Examples include the Ruwenzori Mountain range in Central Africa and the Sierra Nevada in the south-western USA.

People now live and work in high-rise buildings which depend on artificial energy sources like electricity. In the natural world, insects like spiders use a saliva-made fibre to construct their steely web. Termites build intricate airway systems in their habitat. In the same way, some architects and engineers have turned to nature for inspiration when designing buildings. These are called …

Batholiths are enormous masses of igneous rock made up of once-molten material solidified below the earth’s surface. These are usually made of granite and extend over thousands of miles. A well known batholith is located in the Sierra Nevada range of California, across 40,000 sq km.

An ‘anticyclone’ is opposite to a cyclone, in which winds move into a low pressure area. In an anticyclone, winds move out from a high-pressure area with wind direction clockwise in the northern hemisphere, anti-clockwise in the southern hemisphere. Such a high pressure area is usually spread over a large area, created by descending warm air devoid of moisture. The …

In most cars is power from the engine is used to drive either the front wheels or the back wheels. This contact with the road provides sufficient grip on all normal road surface. But when the roads surface is slippery such as when covered by snow or ice, two wheels may not get enough grip and one or both may …

It is not true that there are no tidal waves during the day. Tidal waves are the result of the gravitational pull of the moon and the sun, but the effect of the sun is much less than that of the moon. In fact, tidal waves occur twice on any day-night cycle of 24 hours — once when the moon …

In about 1500 B.C., Queen Hatshepsut of Egypt sent a fleet to the ‘Land of Punt’. No-one is sure where Punt was, but experts think the Egyptian sailors ventured out of the Mediterranean and sailed south along the coast of Africa. Astonishing voyages were also made by Arab and Chinese explorers. People from Asia reached Australia 25,000 years ago, by …

With video, you decide what to watch, you can use your television set to provide you with the films, shows, music-virtually any visual entertainment or information-of your choice. There are two systems: videotape recorders and videodisc players, each with their own particular advantages. Videotape and videocassette recorders play tapes and you can record television programmes on them as well as …