Which scientist demonstrated that skin color in humans exhibits polygenic inheritance?

Grain colour in wheat is determined by three pairs of polygenes. Following the cross $AABBCC$ (dark colour) $\times$ $aabbcc$ (light colour),in $F_2$ generation,what proportion of the progeny is likely to resemble either parent?

Which one of the following is an example of polygenic inheritance?

Which characteristic is responsible for human skin color?

Inheritance of skin colour in humans is an example of

In tomatoes,a plant with the genotype $aabbcc$ produces $100 \,g$ tomatoes,and a plant with the genotype $AABBCC$ produces $160 \,g$ tomatoes. What is the contribution of each polygene to the tomato weight (in $,g$)?