Radiometric dating techniques available to anthropologists Us xxx no

Amphibian larvae are aquatic, and have gills for respiration; they undergo metamorphosis to the adult form.Most amphibians are found in damp environments and they occur on all continents except Antarctica.Then, even if circumstances change such that it no longer provides any survival or reproductive advantage, the behavior will still tend to be exhibited -- unless it becomes positively disadvantageous in the new environment.

radiometric dating techniques available to anthropologists-16

The term can also be applied to larger groups of organisms, as in "the adaptive radiation of mammals." adaptive strategies: A mode of coping with competition or environmental conditions on an evolutionary time scale.

Species adapt when succeeding generations emphasize beneficial characteristics.

ammonoid: Extinct relatives of cephalopods (squid, octopi, and chambered nautiluses), these mollusks had coiled shells and are found in the fossil record of the Cretaceous period.

amniotes: The group of reptiles, birds, and mammals.

They have moist scaleless skin which is used to supplement the lungs in gas exchange.

The eggs are soft and vulnerable to drying, therefore reproduction commonly occurs in water.

antibiotic resistance: A heritable trait in microorganisms that enables them to survive in the presence of an antibiotic.

aperture: Of a camera, the adjustable opening through which light passes to reach the film.

amphibians: The class of vertebrates that contains the frogs, toads, newts, and salamanders.

The amphibians evolved in the Devonian period (about 370 million years ago) as the first vertebrates to occupy the land.

In a diploid cell there are usually two alleles of any one gene (one from each parent).

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