What happens when the recombination frequency is greater than 50 in three point crosses

Non parental genes will become higher than that of parental genes

Explanation:

Genes recombine when the chromosomes pieces swap physically along the chromosomes. Recombination frequency determines the percentage of offspring that recombined during the meiosis cell division.In case where recombination frequency becomes greater than fifty percent then the amount of non-parental genes would be greater than half of the total number of genes . This scenario is not feasible as in random assortment  ratio of parental to non-parental genes is 1:1.of genes the Therefore, in any case the recombination frequency will not increase more than 50 percent

is called echinoderms

i'd say that the moon rock is about 2.2 billion years old.