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What causes a population to be stable?

What causes a population to be stable?

A stable population has an unchanging age structure and a constant exponential growth rate r; both structure and growth rate are determined by vital rates (mortality, fertility). This result explains the adjective stable in the term, stable age distribution.

What keeps a population size stable?

What keeps a population size stable? replacement fertility. This is the TFR that keeps population sizes stable.

What is stability in population?

The term stable population refers to a population with an unchanging (but possibly nonzero) rate of growth and an unchanging age composition (i.e., the population pyramid does not change in shape) as a result of age-specific birth rates and age-specific death rates that have remained constant for a sufficiently long …

What means population stable?

Stable populations are theoretical models widely used by demographers to represent and understand the structure, growth and evolution of human populations. By definition, stable populations have age-specific fertility and mortality rates that remain constant over time.

Are population sizes stable in nature?

In nature, population growth must eventually slow, and population size ceases to increase. As resources are depleted, population growth rate slows and eventually stops: This is known as logistic growth.

How would you describe a stable and stable population?

What is a stable and sustainable population?

By definition, stable populations have age-specific fertility and mortality rates that remain constant over time. SUSTAINABLE POPULATION :It is argued that a sustainable population is one that is consistent with sustainable economic development. …

What is stable and sustainable population?

What country has the most stable population?

Country Comparison > Population growth rate

Rank Country Population growth rate (%)
1 Syria 4.64
2 Niger 3.66
3 Angola 3.4
4 Benin 3.39

What is the stable population period in India?

Stable Population Period (1891-1921): According to Kingslay Davis, “India’s population remained almost stationary since 1800 at around 125 million for about 50 years. The population recorded at the time of 1881 census exceeded the figure for 1921 by 1.47 crore.

How are dolphins and fish adapted to live in water?

Both dolphins and fish have adapted to live their whole lives in the water, both have streamlined bodies and fins. But, dolphins are mammals and so they need regularly visit the surface to breathe air to survive, otherwise they would drown. Fish on the other hand extract oxygen from the water and do not need to surface.

Are there any Dolphins left in the world?

They are the Atlantic Humpbacked Dolphin, Ganges River Dolphin, Hector’s Dolphin, Indus River Dolphin, and Irrawaddy Dolphin. Aggressive fishing almost brought about the demise of the spinner dolphin in the eastern Pacific Ocean.

Is the dolphinfish a species of Least Concern?

Though the common dolphinfish is heavily fished by recreational and commercial fishers, its high productivity and young age at maturity have so far protected it from overfishing. Populations are stable and are able to support the heavy fishing. Currently, scientists consider the common dolphinfish to be a species of least concern.

Why are Dolphins considered to be warm blooded?

Like every mammal, dolphins are warm blooded. Unlike fish, who breathe through gills, dolphins breathe air using lungs. Dolphins must make frequent trips to the surface of the water to catch a breath.