- 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.