1. summarize key points
There is breathtaking diversity in life forms, extinct and extant. But within this diversity are patterns, such as homologous traits (i.e. backbones in vertebrates which evolved in the common ancestor to all vertebrates), and repeated parts in structures that have been passed down to many forms of life (i.e. digits in dolphins, salamanders, horses and humans).
All of this diversity and repetition is encoded in the DNA. Genes get turned on or off in individual cells of an embryo, and their protein products cascade to surrounding cells, signaling for different body parts in response to different combos and strengths of signals.
From these gene networks, which are frequently shared between very distantly related organisms (like the nematode worm, fruit fly, and human) come body segmentation, polarity, and limb formation. The study of existing and created mutants has helped us investigate these gene networks and what their normal function is by seeing what they look like when the genes are non-functional.
Carroll runs through embryogenesis - how zygotes begin to divide, and as division occurs, the resulting ball of cells is broken up into geographical ranges of latitude and longitude. There are further divisions that occur until there are specific groups of cells within the whole that have a unique patterning of genes turned on and off. This further regulates gene expression in ever more specific places and groups of cells, leading the rise of body parts and tissue types in the embryo. The finer the detail or pattern (hairs, scale patterns, etc) the more local interactions between cells are responsible.
2. develop an argument bout compelling points
We can think about this in terms of the Delereax reading. All individuals have a singularity in the expression of their genes, and the process of regulation is the virtuality that leads to singularity from the transcendental field of life = self replicating molecules of DNA.
He goes on to state that what happened in embryology is that we made the simple invisible - visible. We can see spots, stripes, and other things as genes turn on and off inside the embryo. This also harks back to Merleau-Ponty's spaz attack against science's reductionist principle. When we break down complicated processes into their component parts and see their interactions to produce a whole, we understand more about the world. This understanding leads to a greater visual experience - one no longer views the fruit fly as some insignificant organism, one understands their origins, and how we all hark back to a similar, intricately-regulated and beautifully -realized common origin. As our understanding grows, so does our appreciation for the diversity and similarities of every form of life around us...
3. talk about these in terms of class ideas
Maybe I'll just merge points 2 and 3 together, because they seem to flow together a lot...
4. words I learned!
erudite: having or showing extensive scholarship; learned
There is breathtaking diversity in life forms, extinct and extant. But within this diversity are patterns, such as homologous traits (i.e. backbones in vertebrates which evolved in the common ancestor to all vertebrates), and repeated parts in structures that have been passed down to many forms of life (i.e. digits in dolphins, salamanders, horses and humans).
All of this diversity and repetition is encoded in the DNA. Genes get turned on or off in individual cells of an embryo, and their protein products cascade to surrounding cells, signaling for different body parts in response to different combos and strengths of signals.
Carroll runs through embryogenesis - how zygotes begin to divide, and as division occurs, the resulting ball of cells is broken up into geographical ranges of latitude and longitude. There are further divisions that occur until there are specific groups of cells within the whole that have a unique patterning of genes turned on and off. This further regulates gene expression in ever more specific places and groups of cells, leading the rise of body parts and tissue types in the embryo. The finer the detail or pattern (hairs, scale patterns, etc) the more local interactions between cells are responsible.
2. develop an argument bout compelling points
Addressing complexity - a thing mean be emergent, greater than the sum of it's parts, but this arises because the interactions between these parts makes for something unimaginably complex (but keep in mind that most people, when they see a fruit fly, see a nuisance and something nowhere near complexity. Thank you science for that expansion of my humility...). Our modeling is based on finding these simple invisible parts, and using our models to find our complexity with those building blocks (back to Holland).
There is a beginning to this order (in the egg) that came from the parent cell before it. So, really, the chicken came before the egg...
Complexity again! It's fascinating how we respond to complexity, thereby creating more complexity as organisms respond to our responses...All of life and evolution is just one huge interaction, between organisms and organisms, between organisms and environment. It takes the normal law that things go to chaos, and throws a wrench in it. Because there is an excess of energy, everywhere you care to inspect.
3. talk about these in terms of class ideas
Maybe I'll just merge points 2 and 3 together, because they seem to flow together a lot...
4. words I learned!
erudite: having or showing extensive scholarship; learned
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