Carbon 14 has a half life of 5,730 years. Scientists measure how much carbon 14 the rock has. For objects older than 50,000 years, scientists will test the age of the things surrounding it.
In the coding region, natural selection tends to eliminate all of the mutations because of the high importance these regions have. The coding region contains genes that synthesize proteins and the changes in the DNA sequence can have devastating effects on the cell. Therefore, there are very few differences in the sequences of coding regions that can help us trace the lineage.
On the other hand, in the non-coding regions, the mutations often accumulate because they have little effect on the cell and the adaptive value of the organism. This enables us to trace up the lineage by comparing the sequences and seeing the differences in the sequences.
Offspring with a 3:1 ratio suggest that both parent that both parent that give rise to this offspring were both heterozygous. Heterozygous individual is someone who has two different allele at a locus whereby by one gene is dominant over the other gene. example of heterozygous parent is a parent Aa pair of alleles. In this pair gene A is dominant over gene a
