"From Atoms to Traits" Reflection
Significance of Mendel
Mendel was an Austrian monk who, through breeding different pea plants, managed to clarify the confusion about blending inheritance. His experiments proved that although different morphological differences occurred among the different pea plants, these traits were not entirely gone because they could reappear in later generations. He also noticed that offspring of the different plants usually resembled one of the parents in particular. Mendel's experiments ultimately altered the previous perception of how heritable variants occurred.
Drawing of DNA and Who Discovered It
Watson and Crick DNA Model
as Drawn by Adam John Holliday
Five Examples of DNA Variation
Point Mutation- A single base-pair change occurs. This mutation inactivates the gene for signaling a molecule that regulates muscle growth.
Insertion- An intruding DNA element disables a gene that is necessary for starch synthesis. The water and sugar levels of the organism are thus altered.
Gene Copy Number- Entire cells are capable of being wrongly duplicated during cell division, which leads to differences between species that result in variation.
Duplication- Homopolymers within sequences are highly prone to duplication errors. These homopolymers being copied can lead to different coloration among organisms.
Regulatory Changes- Mutations in the DNA that control when and where genes are activated can lead to major deformations of an organism.
Evo-Devo
Evo-Devo is a biological field that analyzes the differences in the developmental processes of organisms in order to show the ancestral relationships between them.
Connection between Lactose Intolerance and Human Migration
The ability to digest milk after infancy was an unnecessary trait that hunter-gatherers didn't need to have thousands of years ago. The ability to digest in milk would have been an uncommon and abnormal trait that very few individuals would have possessed. Therefore, as the small population that had this abnormal trait would eventually migrate to different areas and pass this trait onto future generations. For this reason, the populations that were related to these "unusual" ancestors will be lactose tolerant while other population will generally be lactose intolerant.
