8 ms·
Well it's important to note that all organisms (almost certainly) descend from a single common ancestor (https://en.wikipedia.org/wiki/Last_universal_common_anc
by dekhn 2y ago
Well it's important to note that all organisms (almost certainly) descend from a single common ancestor (https://en.wikipedia.org/wiki/Last_universal_common_ancestor https://en.wikipedia.org/wiki/Last_universal_common_ancestor) and the organisms we work with often are quite close on the inheritance tree (really, a graph if you include horizontal gene transfer).
When you collect the same exact protein from a bunch of close species, their underlying sequences often differ by very little and those differences are really just random mutations that occurred and were tolerated. Some proteins got "locked in" as useful and could not really change since so many things depended on them. For example, eukaryotes like humans have a protein called "actin" that is incredibly well consereved across all mammals, and we can even see what appear to be very distant cousins in bacteria- those two parts of the tree of life diverged billions of years ago (you think legacy computing is bad?)
If you start to study biology through the lens of evolution/development (IE, looking at the similarities and differences in close and far related organisms) it starts to become a lot clearer. Many organisms with very different phenotypes actually just contain slight modifications to the parameters of common generator functions- for example, wings and arms seem to derive from the same ancestral body part. Most of the genes that make them are in common, it's just how and when the different genes get expressed that determines the finer details (I'm glossing over a lot here).
So since nearly all the players are the same, it's often not that hard to move a protein from a close relative (mice are pretty close to us) to another without any real loss of function or major change in phenotype. However, there are some fundamental differences that make comparing mice results to humans and sometimes we modify mice to appear more human to make them better model organisms.
(even after working in this field for some 30+ years, I remain constantly amazed any of this works at all. I felt the same way about Google's production environment, which in many ways resembled a very simple organism)
- mncharity 2y ago> If you start to study biology through the lens of evolution/development (IE, looking at the similarities and differences in close and far related organisms) it starts to become a lot clearer. Any suggestions on literature? Paper, survey article, text, whatever? Or any examples/thoughts of using that as a pedagogical framework? I've an oddball interest in exploring what science education content might look like if crafted with far far greater interdisciplinary expertise and resources. So I've wondered what an intro bio might look like with a more... "veterinary + engineering" flavor - broad scope, comparative and cross-cutting, systems concerns, solution vocabularies, etc. As an illustrative bit (years old so maybe now invalidated), perhaps highly-conserved regulatory micro-RNA might be used as a "available complexity" metric to create a much simpler "tree of life" for orientation. Or energy budgets as a lens. Or design themes (eg compartmentalization). Or conserved-outward (eg 16S to RNA to). Or emotive ("yay diffusion, and surfing just above the thermal-noise molecular mosh pit from hell" vs (an Analog Devices engineer's heartfelt) "Brownian motion is the devil. The DEVIL!!"). Or someone's picture book of motifs in cellular and embryonic development (eg perching pigeons spacing themselves evenly along a wire). Or ... . Most everyone is quite reasonably focused on the students and resources and objectives at hand. But that leaves the heavy lifting of exploring for long-term transformative opportunities rather unincentivized. Making it hard to envision just how much potential is being left on the table.
- acomjean 2y agoI think what you are getting at is that life is all very similar. Most species have very similar genes. Why you can study genes in flies and yeast and worms and have it be relevant to human genetics. In very simplified biology genes just make proteins. There is a fair amount of software to find these similar genes across various species called “orthologs” https://en.m.wikipedia.org/wiki/Sequence_homology#Orthology https://en.m.wikipedia.org/wiki/Sequence_homology#Orthology I’ve run some of these tools. They can be a little rough, but generally they work. You are right though, it’s totally amazing it works. Amazing being alive.