Search results
Results from the WOW.Com Content Network
The kiwi is a family of nocturnal birds endemic to New Zealand.. While it is difficult to say which came first, nocturnality or diurnality, a hypothesis in evolutionary biology, the nocturnal bottleneck theory, postulates that in the Mesozoic, many ancestors of modern-day mammals evolved nocturnal characteristics in order to avoid contact with the numerous diurnal predators. [3]
The emitted light and the reflected light combine and may be considerably more visible than the original light. The most visible frequencies are also those most rapidly attenuated in water, so the effect is for greatly increased colour contrast over a short range, until the longer wavelengths are attenuated by the water.
Swimming is a popular activity and competitive sport where certain techniques are deployed to move through water. It offers numerous health benefits, such as strengthened cardiovascular health, muscle strength, and increased flexibility. It is suitable for people of all ages and fitness levels.
A second reason why retinal evolved to be vital for human vision is because it undergoes a large conformational change when exposed to light. [38] This conformational change is believed to make it easier for the photoreceptor protein to distinguish between its silent and activated state thus better controlling visual phototransduction. [38]
Sleep can follow a physiological or behavioral definition. In the physiological sense, sleep is a state characterized by reversible unconsciousness, special brainwave patterns, sporadic eye movement, loss of muscle tone (possibly with some exceptions; see below regarding the sleep of birds and of aquatic mammals), and a compensatory increase following deprivation of the state, this last known ...
Black People Will Swim, based in Queens, N.Y., teaches hundreds of New Yorkers of color, with limited pool access, how to swim each year.
Swim instructors presume that their students want to learn at least one major stroke, probably “freestyle” or what used to be called the front crawl. Even people teaching swimming have been ...
A great cormorant swimming. Aquatic locomotion or swimming is biologically propelled motion through a liquid medium. The simplest propulsive systems are composed of cilia and flagella. Swimming has evolved a number of times in a range of organisms including arthropods, fish, molluscs, amphibians, reptiles, birds, and mammals.