Ineed pls 50 ! distinguish between directional, stabilizing, and disruptive selection. give examples.

All three types of selection are trends across generations in which the average frequency of a trait in a population changes. Population ecologists use ALLELE FREQUENCIES (the proportions of VARIABLE alleles at a given gene locus measured in a population) and measure change across generations.

This is easiest visualized using normal graphs - most individuals in the population will be average (or MEAN) and become fewer at the extremes.

For example, here is a graph of human IQ. 100 is the mean. As it goes higher or lower, there are fewer individuals with those IQ's.

1: most common garden plants prefer loam — soils with a balance of different-sized mineral particles (approximately 40% sand, 40% silt, and 20% clay) with ample organic matter and pore space. however, some plants grow better in sandy soils, while others are well-adapted to clay soils.

2: available water capacity is the maximum amount of plant available water a soil can provide. it is an indicator of a soil's ability to retain water and make it sufficiently available for plant use. available water capacity is the water held in soil between its field capacity and permanent wilting point.

3: it is the same for all living things (plants and animals). it also includes very tiny organisms that our eyes cannot see. they are known as microorganisms, and include viruses, bacteria and fungi.