Contemporary scientists hold that human physical variations, especially in those traits that are normally used to classify people racially—skin colour, hair texture, facial features, and to some extent bodily structure—must be understood in terms of evolutionary processes and the long-range adaptation of human groups to differing environments. Other features may simply reflect accidental mutations or functionally neutral changes in the genetic code. In any given habitat, natural forces operate on all of the living forms, including human groups. The necessary interaction with these forces will affect the survival and reproduction of the members of these societies. Such groups already have a wide and complex range of hereditary physical characteristics; indeed, human hereditary variability is a product of human sexual reproduction, whereby every individual receives half of his or her genetic endowment from each parent and no two individuals except for identical twins inherit the same combination of genetic features. The global distribution of skin colour see map is the best example of adaptation, and the consequences of this process have long been well known.
Grassland Ecosystem: Types and Characteristics | Earth Reminder
Strix cunicularia Molina, Speotyto cunicularia Spheotyto cunicularia lapsus. The burrowing owl Athene cunicularia is a small, long-legged owl found throughout open landscapes of North and South America. Burrowing owls can be found in grasslands , rangelands , agricultural areas, deserts , or any other open dry area with low vegetation. Unlike most owls, burrowing owls are often active during the day , although they tend to avoid the midday heat. Like many other kinds of owls, though, burrowing owls do most of their hunting from dusk until dawn , when they can use their night vision and hearing to their advantage. Living in open grasslands as opposed to forests, the burrowing owl has developed longer legs that enable it to sprint, as well as fly, when hunting. The burrowing owl was formally described by the Spanish naturalist Juan Ignacio Molina in under the binomial name Strix cunicularia from a specimen collected in Chile.
All our CBSE NCERT Class 7 Social Science practice worksheets are designed for helping students to understand various topics, practice skills and improve their subject knowledge which in turn helps students to improve their academic performance. These chapter wise test papers for Class 7 Social Science will be useful to test your conceptual understanding. Board: Central Board of Secondary Education www. All the CBSE Worksheets for Class 7 Social Science provided in this page are provided for free which can be downloaded by students, teachers as well as by parents. So practising these worksheets will promote students problem-solving skills and subject knowledge in an interactive method.
A biodiversity hotspot is a biogeographic region with a significant reservoir of biodiversity that is under threat from humans. A hotspot is an area which faces serious threat from human activities and supports a unique biodiversity endemic, threatened, rare species with representatives of evolutionary of speciation and extinction. To qualify as a biodiversity hotspots on Myers edition of the hotspot map, a region must meet two strict criteria:.