Which graph represents selection that may lead to reduced variation in a population of

Theories about height as a trait, the height of individuals in a population will vary, and most individuals have an average height and fewer are very short or very high.

The effect of stochastic variations on demographic levels (reproduction and death) is much higher for small populations than for large ones. Stochastic variations in demographic levels cause small populations to fluctuate in random sizes.

The environment can directly affect the survival of small populations. Some adverse effects include stochastic variations in the environment, (year-to-year variations in rainfall, temperature) that can produce temporarily correlated birth and death rates (ie 'good' years when birth rates are high and mortality rates are low and 'bad' years when low birth rate and high mortality rate) which causes fluctuations in population size.

Island populations often also have small populations due to geographical isolation, limited habitat and high levels of endemism. Because their environment is very isolated, gene flow is poor in island populations. Without recognition of genetic diversity from gene flow, the alleles are quickly repaired or lost. This reduces the ability of island populations to adapt to new conditions and can lead to higher extinction rates.

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Natural Selection Type Chart

Variation/Population

Details

Class: Middle School

Subject: Health

Keyword: genetic, chart, variation/population

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c