What is the biological significance of the coexistence of multiple causes and one effect?

One cause with multiple effects, multiple causes with one effect and one cause with one effect are naturally formed in the process of evolution of organisms. It may not be possible to say who is more meaningful about the different ways of inheritance. I think in addition to the above three cases, there is also the problem of multiple causes and multiple effects. It is referenced.

According to Izvestia, the color of the eyes of Europeans, for example, is determined by more than 60 genes, which in turn affect skin color. (In the past, skin color was considered a quality trait, controlled by only a few genes).

One cause multi-effect: one gene affects the phenomenon of many traits For example, the feathering gene of the feather chicken not only affects the recoiling of the feathers, but also affects the decrease in body temperature, rapid heartbeat, enlargement of the heart and spleen, and reduced fertility. This suggests that genes influence the performance of a range of traits through physiological and biochemical processes.

Multi-causal effect: The development of a trait is controlled by many genes, a phenomenon known as multi-causal effect. Major gene - One of the many pairs of genes that play a decisive role in the development of a certain trait is called a major gene.

Multi-cause one-effect refers to the control of a trait by multiple genes.

Whereas, one cause pleurality refers to the control of multiple traits by one gene.

Multi-cause-one-effect – a bunch of genes synthesize proteins that are functionally similar.

One-cause pleiotropy – one gene synthesizes an enzyme that controls a bunch of metabolic pathways, such as PFK-1.

The relationship between genes and quantitative traits is often "multi-cause-one-effect" or "one-cause, multi-effect".

The performance of quantitative traits is composed of genetic effects and environmental effects, and its phenotypic values and genotypic values cannot be completely consistent. The heritability of important quantitative traits in sheep is shown in Table 6-1.

Table 6-1 Average estimation of heritability (h2) of main traits in sheep.

The relationship between genes and quantitative traits is often "one source and one effect" or "one cause and multiple effects".

The performance of quantitative traits is composed of genetic effects and environmental effects on DAO, and its phenotypic values are not completely consistent with genotype values. The heritability of important quantitative traits in sheep is shown in Table 6-1.

Table 6-1 Average estimation of heritability (h2) of main traits in sheep.

For example, the height of the person copy

In a certain environment, (assuming that the effect of each gene is equal, note that there are often such words in the stem, especially "equal") is controlled by AABCC (each lowercase gene becomes an uppercase gene increases by 2 cm), becomes AABBCC or AABBCC or AABBCC is 2 cm longer (each uppercase gene is equivalent), and all becomes AABBCC is 12 cm long, which is the quantitative trait.

It is controlled by the micro-effect polybai gene and is phenotypically inadequate

It can clearly distinguish between different zhi types, and only the number of dao has this difference. There are four main characteristics: 1) it can answer the measure, and the measure value shows a normal distribution; 2) showed a continuous difference; 3) susceptible to environmental influences; 4) The genetic basis of the control quantity system is the polygenic system.

It means that quantitative change achieves qualitative change.

It has nothing to do with qualitative change, it is the continuous accumulation of quantity.