- DNA is a double helix structure composed of nucleotides: A, T, C, and G. this is deoxyribonucleic acid — a molecule.
- DNA has a language that it uses to write your instruction manual (a code). Four chemical bases make up your DNA language including:
- Adenine (A).
- Cytosine (C).
- Thymine (T).
- Guanine (G).
- DNA has a language that it uses to write your instruction manual (a code). Four chemical bases make up your DNA language including:
- long chains of dna are called bases. the bases coil into 46 chromosomes.
- a complete set of dna is a genome.
- rna converts genetic material to proteins.
https://www.genetics.edu.au/PDF/DNA_RNA_genes_and_chromosomes_fact_sheet-CGE.pdf
a quote from the ending of the introduction: who we are and how we got here, by david reich:
Before diving into the book, I will recount something that hap- pened during a guest lecture I gave at the Massachusetts Institute of Technology in 2009. Mine was one of the last lectures of the term, meant to add spice to a course aimed at introducing students to computer- aided research into genomes with the goal of finding cures for disease. As I addressed Indian population history, an undergrad- uate sitting at the center of the front row stared me down. When I concluded, she asked me, with a grin, “How do you get funded to do this stuff?”
I mumbled something about how the human past shapes genetic variation, and about how, in order to identify risk factors for dis- ease, it is important to understand that past. I gave the example of how among the thousands of distinctive human populations of India, there are high rates of disease because mutations that happened to be carried by the founders increased in frequency as the groups expanded. I make arguments along these lines in my applications to the U.S. National Institutes of Health, in which I propose to find disease risk factors that occur at different frequencies across popu- lations. Grants of this type have funded much of my work since I started my laboratory in 2003.
True as these arguments are, I wish I had responded differently. We scientists are conditioned by the system of research funding to justify what we do in terms of practical application to health or technology. But shouldn’t intrinsic curiosity be valued for itself? Shouldn’t funda- mental inquiry into who we are be the pinnacle of what we as a spe- cies hope to achieve? Isn’t an attribute of an enlightened society that it values intellectual activity that may not have immediate economic or other practical impact? The study of the human past— as of art, music, literature, or cosmology— is vital because it makes us aware of aspects of our common condition that are profoundly important and that we heretofore never imagined.
text from The genetic legacy of African Americans from Catoctin Furnace, harney, et. al.:
about identity by descent:
IBD segments of the genome—that is, long segments of DNA that are identical in two or more people because they have been inherited from a recent com- mon ancestor. We searched for IBD segments shared between each of the Catoctin individ- uals and ~9.3 million 23andMe research par- ticipants. We identified 55,342 IBD segments shared between the historical Catoctin in- dividuals and 41,799 research participants, ranging up to 60 centimorgans (cM) in length (Table 1, figs. S8 and S9, and tables S5 and S6). We calculated the total IBD shared between each pair of individuals to estimate their most likely genetic relationship; however, we cau- tion that we are likely underestimating the true amount of DNA shared between these individuals, particularly among close relatives (36). In Box 1, we discuss how the relationships between Catoctin individuals and research participants with whom they share DNA can be interpreted (table S7), noting that not all present-day individuals who share DNA with Catoctin individuals are direct descendants. In fact, most connections are likely between col- lateral relatives—relatives who are neither direct ancestors nor descendants of one another but instead both descend from a common ancestor who lived generations before the Catoctin indi- viduals. Further, many of the most distant rela- tives whom we identified may not share a common ancestor who lived in the Americas. Instead, their connection may trace back to an individual who lived in Africa or Europe before their descendants’ arrival in the Americas, either willingly or as part of the transatlantic slave trade.
from who owns the ancient one, by kim tallbear:
For indigenous people, these requests present a conundrum. If more tribes agreed, more local DNA samples would be available for comparison, and the Kennewick Man’s relationship to specific North-American tribes could be clarified. But many are hesitant to participate after centuries of mistreatment of indigenous populations at the hands of Western science.